Structural Analysis of Historical Constructions

Studies of the history of ancient Greek architecture have primarily covered public architecture such as temples and stoa, which had similar architectural forms and structures. Consequently, many studies have been conducted from a formalistic perspective or have focused on design related aspects, and ancient Greek architects’ conception of the structure have hardly been elucidated. Analyzing tombs of the Hellenistic age which have diverse architectural forms and structures is considered to shed light on how ancient Greek architects conceived the relation between structure and design.Against the backdrop described above, with the elucidation of ancient architectural engineers’ conception of structure and design as the ultimate goal, this paper analyzes the impact on the structural characteristics of rock-cut tombs by the ‘position of the connecting part’ and the ‘height of the back passage of a rock-cut tomb’ by performing structural analysis using a three-dimensional FEM analysis program. As a result, above all, it was revealed that the maximum principal stress could be minimized by balancing the position of the connecting part and the height of the back passage of a rock-cut tomb.

Soils and foundation of Bayon temple of Angkor Thom has been studied since 1994 by Japanese Government Team for Safeguarding Angkor (JSA). The main tower of Bayon of 32 m in height from the base foundation mound which consists manmade fill of 14 m in thickness. The foundation was studied and found as a simple shallow direct foundation. This is just like a10 story RC building standing upon thick manmade sand fill without such a deep foundation with piling. At present, such a structure based upon thick sandy fill will lose the foundation stability in rainy season under monsoon climate of South-eastern Asia. The amazing mechanism attributed to the monument the standing for 700 years has been revealed as the unsaturated characteristics of well compacted silty sand.

The Great East Japan Earthquake of 2011 caused serious damage to a number of architectural heritages. Fukushima Photo Museum (Former Laboratory of Electrics Ministry of Communications), constructed in 1922 and designated as the local governmental important cultural property, was damaged. This heritage structure was categorized into an unreinforced stone structure with local tuff stones. The strong ground motion caused cracks in the stone walls, tilting of the pediment, and falling of the stucco ceiling in the rooms. The multi-disciplinary expert committee for the restoration project was established. In order to discuss the seismic reinforcement of this damaged stone building, structural survey was performed at the first stage of the restoration project. The construction material was the local tuff stone characterized by its rather low specific gravity of 1.2. While the joints were made of cement with insufficient bonding strength, the friction coefficient of the joints was evaluated to be as high as 1.5. Finally, the committee proposed the seismic reinforcement by employing prestressing technique utilizing vertical high-strength steel-bars. The girders on the stone walls were placed by utilizing laminated wood panel of the local products. 3-D finite element model was made to detarmine the prestressing force induced. Furthermore, seisimc safety of the structure was ensured by the static structural caluclation acccording to the Japanese Seismic Evaluation Standard of exsisting RCC building. The microtremore measurement was performed before and after the structural restoration. After completion, the long-term monitoring of stress of the prestressig force induced at the steel-bars has been conducted to check the relaxation of the induced stress to the steel-bars.

In this paper, we propose a method for an evaluation method of reinforcement effect of dry masonry in historical monuments applying DDA, which is one of the discrete mechanics methods, to evaluate structural performance and to design effective countermeasures. In DDA analysis methods, we developed a method to evaluate the capacity load after reinforcement of dry masonry by incorporating a spring of the reinforcement member, and verified the reinforcement effect using this method. From the numerical analysis, it was confirmed that the results differ depending on the installation location, and these parameters affect the performance. It is important that the masonry construction of dry masonry has an influence on the collapsing mode and capacity load, and it is thought that the non-linear collapsing phenomenon is well simulated by our proposed method. As the result, we tried to propose an evaluation function to verify the reinforcement effect due to the difference in the reinforcement method.

Thatch fields (grasslands where the thatch for thatched roofs is harvested) and thatched roofs are dwindling due to the decline of mutual aid, lifestyle changes, and modernization of agriculture. In recent years, there has been a shortage of thatch needed to replace even cultural heritage thatched roofs, making the maintenance of ordinary thatched buildings more impractical. This study aimed to identify modern maintenance and management methods of thatch fields in Shikoku based on case studies of self-procurement of Japanese pampas grasses in Shikoku. We surveyed seven fields that had harvested grasses as a material for thatched roofs within the past five years. We interviewed managers and harvesters of those fields regarding the harvesting process from November 2021 to February 2022. Results showed that the harvesting process depended on the availability of snowfall and storage warehouses. In conclusion, there were both technical issues in making “Kuro” and facility issues in storing grasses to sustain thatched roofs.

In Armenia, the rubble core method was used to build numerous extant churches, several of which are used daily. However, the country has a high risk of earthquakes, and some buildings are significantly likely to collapse owing to structural damage, including deterioration over time. In this study, detailed structural assessments of the deterioration of two typical churches were conducted.First, we discuss the on-site vibration measured and the vibration characteristics identified using a detailed three-dimensional structural analysis of the church of St. Hripsime. [1] The St. Hripsime church has large cracks inside and deterioration caused by water leaking from the inside due to the partial peeling of the south side wall surface. We infer that the vertical cracks observed in the niche may have been caused by previous small and medium-sized earthquakes. An analysis considering damage and deterioration quantitatively estimated a decrease in ultimate strength.Next, the vibration characteristics of Etchmiadzin Cathedral are presented, and the findings of a detailed structural characteristics analysis assuming damage and deterioration are described. The drums and domes of Etchmiadzin Cathedral are elongated compared to the substructure and have four independent pillars in the center. Finally, we discuss the results of an investigation of reinforcement plans focusing on the earthquake damage to the dome and the drum components of these churches.

Ensuring the seismic resilience of traditional rammed earth and stone masonry buildings in the Kingdom of Bhutan is essential for their preservation. This study aims to clarify the vibration characteristics of traditional masonry buildings during an earthquake, based on shaking table tests and seismic response analyses. Shaking table tests were conducted on four 1/6 scaled specimens of the same design and geometry as the full-scale specimens in previous studies. The test results clarified the relationship between the nominal PGA and acceleration response factor and the change in the vibration characteristics due to damage. For the numerical modelling, two-mass system models for each specimen were constructed based on the microtremor measurements conducted for each specimen before the shaking table tests and static full-scale lateral loading tests. Seismic response analysis, using two-mass system models, was conducted to simulate the dynamic behavior observed and recorded during the shaking table tests. The results showed that the numerical analysis produced a similar output trend until rocking or large horizontal cracks occurred.

After the Meiji Restoration in 1868, masonry techniques were introduced to Japan by the West, and Japanese architectural engineers were taught new techniques in construction. However, Japan is an earthquake-prone country and the Great Kanto Earthquake that occurred on September 1, 1923, in particular, caused devastating damage from Tokyo to Kanagawa. Consequently, masonry structures were deemed unsuitable in Japan, and reinforced concrete (RC)—which was introduced from around 1900—moved into mainstream fire-resistant construction. In the first quarter of the twentieth century, when the architectural structure was in a state of transition, a mixed structure that comprised brick walls and RC slabs was attempted, but the full picture was not clarified. Through an analysis of articles that were published by the Journal of Architectural Institute of Japan and drawings of mixed-structure buildings, this study examines the characteristics and changes of the mixed structure. Until 1910, concrete that was poured over shallow vaulted brick or corrugated iron plates that were combined with steel beams were widely used in the construction of fire-resistant floors. Simultaneously, there were examples of RC structures that were used in the construction of stair landings and entire staircases. After 1910, fireproof floors that were built with RC slabs on steel beams made way for RC slabs that used both small and large beams and haunching beams.

Snow load effect to vibration characteristics of Japanese traditional wooden main temple building and three-story pagoda of “Jion-ji”, Japan is studied using ambient vibration measurement and earthquake observation data. The 1st natural frequency of the main temple building ranged from 1.07 to 1.73 Hz in EW and 0.98 to 1.88 Hz in NS. The 1st natural frequency of the pagoda ranged from 1.23 to 1.66 Hz in EW and 1.20 to 1.49 Hz in NS. As a result, vibration characteristics of those heritage structures were affected by snow load distribution on the roof and amplitude of earthquake. In winter, thickly accumulated snow leads to the additional load, having caused the significant change of the vibration characteristics of the structure. The snow load on the natural frequency was as effective as small earthquakes. Large amplitude of strong earthquake is more effective to vibration characteristics of those buildings and decrease the natural frequency. From an earthquake engineering point of view, the equivalent mass of the structure with the snow load in winter was 1.9 times as heavy as that in summer, which indicated seismic safety of the structure would be affected by the snow load in snow area.

Mud walls, which have been used since ancient times in Japanese timber structures, have the advantages of being harmless to the human body and having a low environmental impact. However, as the quality of the materials is not uniform, it is difficult to clarify the mechanical properties without conducting the strength test. Therefore, in this study, compression and shear tests were performed on the wall clay. Furthermore, authors performed multiple regression analysis to derive the estimation formulas for the wall clay strength using the material properties, e.g., mixing ratio, particle size distribution, and wall clay density. As a result, the soil source, maturity period, and sand volume in the second coating soil affect the wall clay strength. The strength ratios of compression and shear of the wall clay were divided between 57% and 64% of the passing mass percentage of grain size 0.075 mm. The estimation formulas for the compression and shear strengths of the wall clay agreed with the measured values when the soil test data, water content, and density of the wall soil during construction and after drying were combined. Furthermore, shear strength could be estimated using the passing mass percentage of grain size 0.075 mm and average compressive strength.

Considering the limited strength of traditional masonry structures, retrofitting is essential. The purpose of this study was to discretize a numerical model that can be used to assess the behavior of brick masonry in earth mortar. The behavior of unreinforced brick masonry (URM) and brick masonry reinforced with timber was investigated through numerical simulation. The flexural strength of URM and reinforced masonry prism of size 280 mm x 350 mm x 860 mm (B x D x L) was calculated by three-point bending experiments. For reinforced masonry prism, ladder and diagonal brace reinforcement with timber were studied. From the results, it was observed that the diagonal brace reinforced prism withstood higher flexural tensile stress compared to the URM and ladder reinforced prisms. From the uniaxial compression test conducted on the same size of masonry prism, the elastic modulus (E) calculated was 310 MPa. A homogenous macro model was used in ABAQUS software to reproduce a previously performed three-point bending test of a prism built of brick masonry in earth mortar. Material properties such as density, E, and Poisson’s ratio were input to the software. The displacement value obtained was very low compared to the experimental result when E of 310 MPa determined from the uniaxial compression test was taken. The reason might be due to the involvement of both tensile and compressive forces in the bending test. In this study, the elastic modulus in tension (Et) was considered 1/5 of that in compression (Ec) for URM prism. Numerical model for the URM prism gave closer results to experimental value when Ec was 41 MPa, which was 1/8 of E determined from the uniaxial compression test (310 MPa). In uniaxial compression test, the direction of compressive strut formed was 90° to the bed angle. However, in three-point bending test, a compressive strut was formed from the point of loading to the supports. For URM and diagonal braced specimen compressive strut formed was 56.3° to the bed angle (θstrut), whereas for ladder reinforced specimen, it was 37.2°. For the ladder and diagonal braced reinforced model, crack was assumed at the tensile side of the masonry. By trial and error, the numerical result was in good agreement with the experimental value for maximum displacement at the mid-point under the condition that the E of 20.5 MPa and 41.0 MPa was taken for the ladder and diagonal brace model, respectively, with a 70 mm crack at the tensile side of masonry. In the analysis, it was observed that for URM and diagonal brace reinforced model, E was greater than for the ladder reinforced model. Namely, with the increase in compressive strut angle (θstrut), there was an increase in the value of E.

Throughout the years, historical monuments have been at risk from natural and man-made causes. Impact loading analysis plays an important role in structural engineering and is one of the risks to existing construction, whether being through partial collapses, vehicle crashes, or historical or modern-day warfare. This case study analyses the local response of a wall portion of the Torre de la Vela, a rammed earth tower within the UNESCO World Heritage Site of the Alhambra, Grenada, under impact loading. For this case study, the wall section of the tower was modelled with finite element methods (FEM) using different modelling approaches: using a continuum model, using a continuum model with removal of damaged elements, and using a contact element model. The Concrete Damage Plasticity (CDP) material model was adopted for the rammed earth structure. Different impactors were considered, including a cannonball with properties from the 16th and 17th centuries. The effect of impulsive loading on the material properties was accounted for using existing dynamic increase factors. The problem was solved using the explicit dynamic analysis available in Abaqus/Explicit. The different modelling strategies were compared and discussions on the use of different approaches were raised.

Reverse engineering is a process in which an existing object is studied to understand how it works and potentially improve it. In the Cultural Heritage (CH) sector, 3D scanning and parametric modeling tools have made reverse engineering a viable approach for studying and understanding historical buildings. This paper presents a method for studying the displacements and deformations in historical masonry buildings over time using reverse engineering techniques, such as Terrestrial Laser Scanning (TLS) and parametric 3D modeling. The proposed workflow is divided into three phases. First, a digital survey is conducted to create a 3D point cloud that accurately represents the current condition of the building's structural elements. This point cloud is called the Basic 3D Model (B3M). Next, the point cloud is reconstructed as a 3D NURBS topological model, and specific visual programming algorithms are used to cancel out the hypothetical deformations that have occurred over time. This model is called the Ideal 3D Model (I3M) because it represents the theoretical, undeformed configuration of the structures. Finally, the I3M is compared to the B3M to identify the deviation between the deformed and undeformed configurations. This comparison allows for determining the structural behaviour of the building's parts and evaluating the overall condition of the building to guide interventions for structural improvement. The method has been applied to several case studies in Italy, including masonry columns, façades, and timber trusses.

This study contributes to the structural assessment of the main pyramid in the archaeological complex of Huaca de la Luna, Peru. Built with millions of adobe bricks by the Moche civilization (200–850 A.D.), the monument is one of the largest adobe structures in the world. Located in a seismically active area, the monument shows signs of severe natural and anthropogenic damage. The pyramid was built as a succession of taller and larger platforms, each formed by erecting adjacent but disconnected vertical piers made of adobe masonry. A multiscale 2D nonlinear FE model is introduced for assessing the contribution of this pier architecture to the dynamic response of the pyramid. A representative cross-section of the pyramid is analyzed under plane strain conditions. Critical regions are modelled with individual piers represented by macroblocks separated by frictional interfaces, while a continuous description is adopted for the remaining part of the model. The analysis is performed in Abaqus/CAE Explicit using concrete-damaged plasticity and Mohr-Coulomb formulation for adobe construction and soft soils, respectively. The time-evolution of elastic strain and dissipative plastic energy is used to follow the development of local damage conditions up to structural collapse. The structural assessment includes (i) a quasi-static analysis aiming to predict the stress state due to gravitational loads, and (ii) dynamic analysis to identify lateral capacity and failure mechanisms triggered by monotonically increasing ground acceleration. Sensitivity analyses was conducted to evaluate the effect of the contact friction coefficient and the number of macro-blocks used to discretize the critical area.

The Gongsanseong Fortress is a fortress built to defend the capital of Baekje Kingdom, and has been inscribed on the World Cultural Heritage for its outstanding historical value as a cultural site that allows one to see Baekje culture and construction techniques. In 2013, part of the rampart collapsed due to localized heavy rainfall, and since then, scientific and engineering studies have been conducted for its stable conservation. Based on these studies, a maintenance system has been established, and is still in operation currently. Automatic measurement equipment was installed on structurally unstable ramparts to measure the microscopic movements, and it was found that the walls in the pond site (Yeonji) on the north side of the Gongsanseong Fortress moved the fastest. The movement of the wall is concentrated from winter to thawing season, and it is repeated every year. It was interpreted that the movement is caused by the freeze-thaw action of water. To visually confirm these movements, we compared 3D scan data taken in 2014 and 2021. From the analysis, the largest deformation occurred in the central part of the wall in the horizontal direction of the wall, while in the vertical direction, the deformation was more concentrated in the lower part of the wall than in the upper part. Deformation outside the tolerance range was observed in more than 70% of the ramparts, where the walls were pushed and protruded towards the frontal direction. The movement of the wall, as measured by some measurement sensors, takes the form of a reversible deformation that returns to the original movement after structural deformation. However, the 3D scan data shows that this movement is irreversible, which is different data from the measurement sensors. These results indicate that the application of a two-dimensional measurement technique to capture the spatial movement in a 3D space may distort the reflection of an actual movement, so the possibility of such distortion must be considered in the interpretation of the two-dimensional measurement results.

The Tomb of King Muryeong and the Royal Tombs in Gongju, Republic of Korea has been registered as UNESCO World Heritage sites in 2015 regarding the values as one of the representative cultural heritages of the Woongjin period (475 to 538 AD) in Baekje Kingdom. After the excavation of tombs, several damages occurred due to rapid environmental change. This study uses a 3D precise scanning to visualize microscopic changes in wall composition materials that are difficult to distinguish using sensors and record 3D shape information on vulnerable parts within the tombs. In addition, the obtained data were used to calculate the displacement during the study period through comparative analysis with the previous data of the tomb complex. Based on the RMS deviation analysis, no visible deviation was found in the tolerance ranges ± 2 mm and ± 1 mm. The results indicate that no additional cracks or detachment occurred in all vulnerable parts. However, the displacement analysis confirmed the sagging behavior for the lintel in the Tomb No. 5, which also appeared in the position transducer installed at the Tomb No. 5, indicating that minute movement occurred. It is estimated that the steel supports currently supporting the lintel are not providing adequate support due to corrosion, therefore reinforcement should be considered. The results of this study are expected to be applied as important basic data in preparing and processing conservation measures for the Tomb of King Muryeong and Royal Tombs in Gongju in the future.

Constructions can show cracks due to mechanical stress. Such cracks have been investigated for decades by means of mapping and manual measurement of crack widths. During the formation of a crack, the flanks separate from each other. The shape of the crack flanks and the relative motion of the flanks are independent of each other. To draw precise conclusions from cracks observed in a construction, a quantitative parameterisation of these cracks is desirable. Often the crack opening width and the opening direction can be assumed to be homogenous at least in sections, defining a unique crack opening vector. Here we present algorithms to automatically characterise cracks by determination of their opening vector based on digital images. The algorithms presented here permit to perform a quantitative and reproducible analysis with weak subsidiary conditions imposed on the photographs. The central parameterisation algorithms are robust against many interfering picture properties and do not depend on the exact position of the crack under consideration within the photograph. The precision of the extracted parameters can be estimated based on a statistical analysis. By using the algorithms for the analysis of true-to-scale rectified images metrical quantities can be obtained. It is possible to integrate the developed applications into the documentation process. The methods can be used together with deformation analysis and other complementary techniques. When working with rectified images the rectification parameters might be transferred automatically between similar pictures; this might be used in the analysis of a temporal sequence of images or to improve detail resolution. The algorithms described here might be used as a basis for assessing the precision of the extracted crack parameters without the need of a statistical analysis. In a more distant perspective, patterns consisting of several cracks might be analysed and the overall relative motion of sections separated by cracks might be deduced, to carry out a combined analysis of several cracks.

Old buildings were often constructed adjacent to each other, without the minimum gap recommended by modern codes. This further increases their seismic vulnerability by exposure to the risk of pounding, a complex mechanism involving repeated impacts between adjacent buildings. Although post-earthquake surveys worldwide confirmed that seismic pounding can significantly increase the extent of in-plane damage and cause early collapses, this phenomenon still remains largely unexplored, while ad-hoc assessment guidelines are missing. This preliminary study focuses on investigating the mechanical in-plane interaction among low-rise unreinforced masonry (URM) buildings of clay brick, a seismically vulnerable yet common structural typology across Canada and abroad. The main novelties consist in the unprecedented use for this task of experimentally validated numerical models developed in the Distinct Element Method (DEM) framework, enabling us to map accurately crack propagation up to collapse, as well as the quantification of key material and geometrical factors affecting earthquake performance. To reduce the otherwise prohibitive computational expense typically entailed by DEM and consider building-scale models, a new macro-modelling strategy is devised that idealizes masonry as an assembly of solid rigid blocks connected by nonlinear interface springs, forming an equivalent macro-crack network where failure occurs according to linearized softening joint constitutive laws. Using this expedited yet accurate analysis technique, a comprehensive parametric study is conducted to investigate the pounding of adjacent URM façades of varying height, material degradation levels and opening layout, tested under pushover loading schemes. Preliminary results, which also account for the stochastic nature of the mechanical properties of masonry, seem to suggest that the severity of damage due to building interaction is particularly dependent on the material properties, adjacent building numbers and the building height. These results will inform ongoing research on seismic pounding at McGill University, where the effect of dynamic loading will also be considered.

This paper presents an improved 2D modelling strategy which aims to represent the behavior of historical unreinforced masonry buildings on shallow foundations subjected to ground settlements. The application is presented with reference to a two-storey building, typical of the Dutch built heritage. The novelty comprises the inclusion of the effect of the lateral house-to-house separation walls of such old buildings. Additionally, the masonry strip foundation is modelled and supported by a boundary interface representing the interaction between the soil and the foundation. Two realistic hogging and sagging settlement configurations are applied to the model and their intensity is characterized using the angular distortion of the settlement shape. The response in terms of damage and deformations of the proposed modelling strategy is compared with the ones of five selected approaches based on the state of the art. For all the selected models, the damage severity is quantified objectively by means of a scalar parameter, which is computed considering the cracks’ number, length, and width.The results of the proposed 2D model agree in terms of displacements, crack patterns and damage with the 3D models. On the contrary, the façade models that do not include the effect of the lateral walls do not exhibit the same cracking and damage, resulting in lower damage and deformations for the same applied angular distortion. Accordingly, the proposed modelling strategy requires less modelling complexity and the analyses are 9 to 28 times faster to run with respect to the 3D models. The efficient and accurate model allows performing a wide number of analyses to easily investigate the role of the various building’s features.

The load multiplier of failure mechanisms represents an analytical evaluation of the behavior of a building during an earthquake. Provided that disaggregation phenomena are inhibited, out-of-plane mechanisms are the most hazardous among the possible failure modes in masonry buildings. The overturning can involve a wall either by itself (simple overturning) or by dragging a portion of the orthogonal wall (wedge-shaped overturning). Many literature works explored the geometry and load factor of these mechanisms. Notwithstanding, they led to various interpretations of the same failure mechanisms, especially when friction among the masonry units is considered. In addition, these theoretical approaches assume a monolithic drystone ashlar masonry, but common historical buildings in Italy, with roughly cut stone units randomly arranged on wide joints filled with poor mortar, can barely fit this condition.The paper compares the load multipliers for nine overturning mechanisms, both simple and wedge-shaped, calculated according to five literature approaches, of which three consider the influence of friction. These mechanisms were observed on seven masonry buildings in the historical center of Castelsantangelo sul Nera, hit by the 2016 Central Italy earthquake. The comparison enables to evaluate the contribution of frictional resistances to the loading conditions.Among those explored, two approaches which consider friction obtained similar outcomes, whereas the third one overestimated the multipliers. In general, frictional resistances increased load factors. Furthermore, the analysis on real buildings gave the possibility to compare the analytical outcomes of the expected failure mechanism with the real damage pattern and the real registered seismic action.

As notched beams are often and commonly found in historic structures, the assessment of potential bearing capacity is of utmost importance. In practice a few equations are found in the standards dealing with the problem, nevertheless, common use is only on tension side near the ends of the beams. To fill the gap and also allow for computing the critical force of arbitrary notched beam under arbitrary loads the authors use energy-based approach along with FEM. The idea is based on simple virtual crack closure technique and calculation of the work consumed by the crack to grow. Such a method is able to assess the bearing capacity of the whole beam. This procedure allows for a detailed analysis of the problem in real structure. The method described above is documented in the paper and a numerical model is constructed in ANSYS. The assessed values are compared to experimental work on real timber beams. Experimental work consisted of testing 9 beams (softwood; Norway spruce) with dimensions 0.2 × 0.25 × 5.9 m, a cut in the central part of the beam and 4-point bending load scenario. The numerical analysis is able to assess the critical load relatively well. Results are critically evaluated and drawbacks are discussed in-depth.

Heritage buildings and historic structures are highly complex systems that have to be understood by performing multi-, inter-, and transdisciplinary studies. It is therefore important to understand how structural parts influence each other and how individual structural elements and their position affect the general behaviour of the whole system.Recent studies concerning roof structures have highlighted that there is a close link between all structural elements, not only from a load-bearing point of view but also from a geometric point of view. Therefore, it was observed that the general shape of the roof and the position of the main structural elements were defined by complex geometric ratios.Starting from this observation, the study is aimed at evaluating how important these geometric ratios are in the structural behaviour of historic timber roof structures from the 18th, 19th and 20th century from Timisoara. To evaluate their importance, numerical simulations were performed on the main frames of the selected case studies with original geometric ratios and altered ratios and their behaviour was compared in terms of displacements in key areas of the structure. The main scope of the study is therefore to highlight whether the presence of pure geometric ratios improves the structural behaviour of the considered roof structures or if these principles are only related to the general aesthetics of the roof structure.

In unreinforced masonry structures, one of the most dangerous events that can occur during earthquakes is an out-of-plane mechanism. This type of response significantly changes if the wall is restrained by a horizontal element, like a floor, a roof or tie rods. The collapse, in this case, could take place for slipping/failure of the connection to the diaphragm or for overturning of the wall, following the formation of a crack at an intermediate height between the base and the top. Further, to evaluate the response of these kind of mechanisms, the assumption of a rigid top support can be too crude especially in case of a timber diaphragm or small diameter and large length tie rods.In this context, in order to capture the complex dynamic behavior of the wall, formed by two stacked rigid bodies (free to rock) connected to a spring, a specific analytical model (updated to account for additional masses active on the wall only during the earthquake) is used.For slender walls connected to a flexible restraint, the flexural out-of-plane mechanism is recurrent. These walls are common in the Emilia-Romagna region of Italy. For this reason, a building portfolio in Emilia is analyzed to derive mean and standard deviation of a log-normal distribution of the main parameters of the system.The variation of relevant parameters is investigated, in order to evaluate the effect of the elastic restraint at the top. The results of the analysis highlighted that stiff diaphragm can significantly reduce the rotations. Additionally, the study on the effect of the wall size pointed out how the top spring causes a reverse scale effect.

One of the characteristic features of the city of Utrecht is its extensive system of canals and wharf cellars, whose constructions date back as early as the 1200s, and which are now considered as one of the historical properties of the city. A typical wharf cellar in Utrecht comprises a masonry barrel vault with multi-layered rings for the cellar interior, masonry piers which are interconnected to the other wharf cellars, and spandrel walls for the façades. Due to increased traffic volume and urbanization which caused the increase of dead load and traffic load, it is important to assess the structural safety and state of maintenance of these historical structures. In this paper, a novel safety assessment framework for these structures is presented and applied to the analysis of a typical masonry wharf cellar in central Utrecht. The geometry of the cellar is first parametrically generated, which is then used to create a block-based numerical model for analysis using the Distinct Element Method (DEM), where bricks units are modelled as discrete blocks separated by zero thickness interfaces. Traffic loads in accordance with the Dutch Standard traffic model for regular vehicles and emergency service vehicles are calculated and the dispersion through the filling soil is modelled. The ultimate load due to these load configurations is then assessed. The analysis results can be used to identify the critical load cases and the failure mechanisms of the wharf cellar, while also providing general insights into the safety and stability of the cellars, thus aiding engineers in their efforts to extend the lifespan of these historical structures.

Bracket set frame (BSF) consists of two column-head bracket sets (CHBSs) and one beam (Tiaojianliang), CHBS consists of bearing blocks (Dou) and short beams (Gong), in a unique manner in traditional Chinese timber structures. The mechanical performances of a BSF is different from a rigid joint or hinge joint exhibiting the behavior of a semi-rigid joint. An analytical model of BSF along y-axis direction of a building is proposed. Based on the structural form of BSF, the analytical model of a BSF is composed of rotational spring elements representing the Mantousun (MTS), Dadou with mortise (DDM) and beam elements representing the beams (Gong, Fang and Tiaojianliang). The accuracy of this model is validated with a solid element model with the same geometric dimensions and mechanical parameters. Effects of the vertical load and section dimension of Tiaojianliang on the load resistance capacity of BSF are analyzed. Result suggests that the load resistance capacity of BSF will increase significantly with the vertical load increases. The load resistance capacity of BSF will decrease with the section dimension of Tiaojianliang decreases.

The Crypta Neapolitana is a historic tunnel attributed to Lucio Cocceio Aucto, a Roman architect of the first century AD. It runs within the current urban area of the city of Naples and crosses the Posillipo hill, that separates the Gulf of Pozzuoli from that of Naples. Since about one century the tunnel has been not used for its original purpose, due to the creation of other larger road and rail tunnels nearby. After being abandoned, several disruptions occurred along its route and the Crypta is not accessible anymore to the public. The tunnel runs across different pyroclastic formations: the deeper layer is a weakly cemented old tuff, with poor mechanical properties, that can be considered a transition material between an uncemented pyroclastic silty sand (pozzolana) and a tuff, with some specific sections in which cohesion is close to zero.To check the current static conditions of the tunnel, an in-situ investigation was conducted and elastic-perfectly plastic 2D analyses were performed with the FE code Plaxis. The main results are briefly summarised in this paper. They indicate that most times the critical instability mechanism is the onset of tension cracks at the sidewalls and the subsequent collapse of blocks, consistently with the evidence of the field survey.Therefore, before the historic tunnel is re-opened to the public, a diffused reinforcement is required.

This paper presents the stability verification of an old masonry tunnel that belongs to the archaeological site of ancient Nemea, Greece. The calculations are carried out using a 2D nonlinear finite element analysis with a damage model. The study presents the results of a structural evaluation in the case that the overburden load above the tunnel increases. This tunnel was initially studied by Alexakis and Makris (2013, 2014) and solutions were provided using Limit Analysis. In this study, a comparison is given regarding the calculated bearing capacity of the tunnel between Limit Analysis and the proposed FE model. Then, several aspects of the numerical modelling of masonry tunnels are discussed. Firstly, the influence of the constitutive law of masonry and the differences between the damage model and two plastic models. Secondly, the stiffness of the surrounding ground, which has an impact on the bearing capacity of the tunnel because the earth pressure is a function of the deformation on the tunnel. And finally, the mesh size, which impacts the depth of the cracked zone and produces a variation of about 15% in the bearing capacity results. From the damage model it was found that horizontal convergences are about 3 cm before failure. This output is a major advantage of the FEM analysis with respect to limit analysis, for it allows to suggest some displacement thresholds. Lastly, a brief discussion is presented regarding the rotational capacity of the hinges as a stability verification criterion.

Large support displacements are a major threat for masonry arches. In the last decades, the stability of masonry arches under large support displacements has been often analysed through analytical and numerical methods that adopted Heyman’s assumptions on the behavior of masonry arches and modelled arches as rigid-no tension structures. Although these methods were generally able to capture the collapse mechanisms observed in the experimental tests, they overestimated, even significantly, the experimental displacement capacity. The main aims of this paper are to investigate the reasons why rigid-no tension models fail in accurately predicting the actual response of dry-joint masonry arches to large support displacements and to propose a numerical modelling approach able to obtain a better matching between experimental and numerical responses. To achieve these goals, the case of a small-scale segmental dry-joint masonry arch tested to collapse under vertical, horizontal, and inclined support displacements was investigated. To simulate the experimental tests, a finite element micro-modelling approach was adopted. The arch was schematized as an assemblage of elastic and stiff voussoirs interacting at no-tension friction interfaces, which were considered alternatively rigid or deformable. The comparison between the numerical and experimental results demonstrated that the discrepancies between the predictions by rigid no-tension models and the experimental outcomes were due to the imperfections and resulting deformability of the joints of the physical model. A strategy to account for this deformability in the adopted modelling approach was thus proposed and validated by comparison with the experimental results.

This paper presents the structural damage assessment of Nostra Signora della Bastia sanctuary, a historic masonry church located in the Liguria region (Italy) in an area affected by slow-moving landslides. The church exhibits extensive cracking and large deformations, which are mostly localized in the central and lateral naves. To identify the causes of damage and deformations, structural analysis was carried out in combination with crack-pattern surveys, laser scanner surveys and deformation analysis. The deformation analysis suggested potential causes of damage and allowed damage mechanisms to be preliminary identified. Following what emerged from the deformation analysis, graphic static and kinematic analyses were performed to assess the structural safety of the most damaged elements of the church. Although the graphic analyses indicated the presence of further causes of damage, they provided further insight into the structural response of the church, showing the potential offered by the combined use of deformation and structural analyses for the structural damage assessment of historic masonry structures.

Block-based models, which can account for the actual block-by-block masonry texture, are becoming more commonly used for the analysis of historical masonry structures, given their high accuracy in representing masonry mechanics and their computational demand which has become lately approachable. However, the implementation of full-scale models where every single masonry block is accurately represented can be time-consuming, and even impossible, due to lack of relevant data. In this contribution, a 3D non-periodic masonry pattern generator is proposed for the block-based analysis of full-scale historical structures. This approach uses as input the digital solid model of the structure, in terms of voxels, and a representative texture of a small portion of a wall. The generator automatically creates the block-by-block arrangement of the whole structure through a pseudo-statistically meaningful representation, also in case of multi-leaf walls. An example of cultural heritage structure is used to assess the effectiveness of the automatic generator. Then, pushover-like analyses are conducted by means of an available block-based model, investigating the masonry texture influence on full-scale mechanical responses.

Masonry tunnels are underground structures which can experience degradation due to ageing resulting in damage or cracking. In this work, the stability of these structures is studied using the upper-bound kinematic approach of yield design theory. This method allows estimating the ultimate load of any system knowing the geometry and the strength of its constitutive materials. However, the determination of the optimal failure mechanism, that is to say the one giving the upper-bound of the ultimate load, can be tricky as regards the interactions between the ground and the structure itself. To overcome this issue, it has been chosen to decompose the problem in two sub-problems. On the one hand, existing kinematic models dealing with the stability of excavations are extended to cohesive-frictional grounds. On the other hand, a mechanism representing the deformation observed on-field is explored to assess the masonry lining stability. Yield design theory is used to determine upper-bound estimations of the ultimate load for excavations in purely frictional grounds, cohesive-frictional grounds, and for a masonry vault subjected to a concentrated load.

The work intends to study and analyse a case study of the City Palace Udaipur in Rajasthan, India. The City Palace complex, Udaipur is an exemplary model of the Rajput palace fortress and its construction lasted 400 years, starting from 1553C.E [1]. The Saleh Khana (armoury museum) had been intervened due to the presence of structural damage [2]. This work focusses on the analysis of the structural condition of the Saleh Khana (armoury museum), within the City Palace of Udaipur, India. In general, two main objectives are achieved. First, the modelling and assessment of the condition of the structure before the interventions are carried out. The obtained results are then compared with the documented damage present in the structure before the interventions to verify if the damage present at the structure was reflected properly while modelling and its only due to the vertical forces acting on the building. Secondly, the modelling and assessment of the condition of the structure after the interventions is carried out. The obtained results are then compared with structural analysis before the intervention to verify the improvements made with the interventions that were proposed and executed. To achieve these objectives, different 3D finite element models of the structure were analysed. The research was able to justify several important damage features of the building. Particularly, good consistency was obtained regarding the damage patterns of the stone frames and the vaulted roofs. Furthermore, the results indicate that the numerical model developed within the scope of this work can properly replicate the overall behaviour of the structure. The efficiency of the interventions executed in the Saleh Khana was estimated, and an improvement on the overall capacity of the structure under vertical loads of 67% can be expected.

The present study focuses on enhancing the seismic resistance of existing masonry structures. To that aim, the use of fiber-reinforced polymer (FRP) strengthening serves to improve structural behavior by attaching FRP strips to the masonry walls. Despite substantial study on the influence of such strengthening interventions on structural elements, computationally efficient numerical models capable of adequately depicting this phenomenon remain scarce. This paper therefore endeavors to develop and validate a numerical modeling approach to capture the effect of FRP strengthening on masonry panels. The proposed modeling approach leverages a newly developed macro-element, capable of capturing both in-plane and out-of-plane modes of failure. This is achieved by incorporating the FRP intervention into the section model through the addition of fibers, while the effect of transversal FRP strips on shear strength is accounted for by a proportional increase in the cohesion within the shear strength equation. This approach is further illustrated through a case study of a masonry building tested on a shake table. Overall, the suggested modeling strategy successfully predicts both the in-plane and out-of-plane response, indicating that equivalent frame models may successfully describe the response of masonry structures with FRP-strengthened walls. To conclude, the models discussed in this study can be employed for a time-effective analysis. Additionally, it can assist in determining the best strengthening strategy for potential retrofitting. For cultural heritage sites, where unnecessary retrofitting should be avoided, this aspect is particularly essential.

The historic district of Jeddah city has a unique traditional building structural system known as the Hijazi style. The structure system of historic Jeddah buildings is based on load-bearing walls and through a unique horizontal load distribution wooden system known as the "Tkalil" system. Moreover, exact identification of this Hijazi building style deficiency necessitates information besides familiarity through the original structural system, as well as the construction method of the Hijazi building style. This can be combined through an advanced scientific method for exploration. This paper will focus on evaluating the Tkalil structural system based on 3D laser scanning and Heritage Building Information Modelling (HBIM) techniques, through different case studies of the historical building in historic Jeddah, Saudi Arabia. Furthermore, the traditional construction technique for historic buildings in historic is multiple-leaf coral-stone masonry load-bearing walls. Moreover, there are several structural deficiencies patterns in these heritage walls which can lead to instability of these heritage buildings structures, as well as the degradation of the structural condition of these heritage buildings' foundations, as well as the flat timber ceilings. Indeed, using advanced techniques for data acquisition (Photogrammetry and 3D laser scanning), then analysing these data via the BIM platform can help to understand the core issues of these heritage buildings before applying any solutions. The 3D laser scanning will provide very detailed and accurate 3D point cloud models. These models will be the base for the heritage BIM models to be evaluated and to indicate the stability of these heritage structural systems.

Safeguard of the heritage of masonry infrastructural constructions is a relevant concern nowadays. The historical-monumental value of a large part of these artifacts, combined with their current functional reuse in the transport networks, make them interesting case studies. These structures are generally afflicted by structural weaknesses that make them vulnerable under dynamic actions, strongly present in the Italian peninsula, due to its widespread and high seismicity. In this framework, Finite Element analysis turns out to be a useful tool to better understand the structural behavior of masonry artifacts. In this paper, the seismic assessment of a masonry arch bridge, located in Italy, is proposed by means of a 3D FE modeling. The masonry material is described through the adoption of a constitutive law with damage, capable of capturing the degrading behavior of masonry under cyclic actions, characterized by a strain softening response. The phenomenological law is characterized by the presence of a scalar damage variable, describing the material degradation evolving during the analysis. After the investigation of modal shapes of the bridge, the horizontal capacity curve was estimated through a pushover analysis, and finally the structure was subjected to a set of natural accelerograms. The health state of the case study was consequently defined by means of damage indexes, and the most critical areas of the bridge were highlighted through the study of the damage patterns.

Among the different finite element modelling approaches available for the description of unreinforced masonry structures, the equivalent frame method is widely diffused. It is, in fact, capable of describing the response of masonry walls with good accuracy, thanks to the possibility of reproducing its main in-plane collapse mechanisms through the schematization of piers, spandrels and rigid zones with one-dimensional macroelements. Nonlinear hinges completed with appropriate constitutive laws are employed for the description of the nonlinear characteristics of masonry, both for shear and flexural mechanisms. In particular, a Bouc-Wen formulation is considered in this study and modified with the introduction of degradation by means of a scalar variable for damage and an additional parameter for flexibility increase, to properly account for the strength and stiffness degrade typical of masonry under cyclic actions. The dynamic behavior of a squat masonry wall under different types of excitations is investigated, as well as the effects of the damage and flexibility increase in the dynamic response of the panel.

Many historic structures in Canada are deemed unsafe and are closed or of limited access to the public. An “unsafe” steel and concrete heritage building rebuilt in 1930 has been analysed structurally. The building in question is the absorption building at the Turner Valley Gas Plant (TVGP), a National Historic site. Throughout the building lifespan the structural skeleton has been adapted to accommodate changes in the oil and gas processing. The TVGP was Alberta’s first natural gas plant built and thus the birthplace of the energy sector in Western Canada. The absorption building housed the first ever absorption plant in Canada in 1914. The load path, effects of modified and missing members, and capacity of elements were assessed. Due to a lack of historical records, Non-destructive testing methods were used to determine building properties. Geometrical data was collected with laser scanners and ground penetrating radar systems. X-ray diffraction, scanning electron microscopy, hardness tests and tension/compression tests were used to determine material stiffness, strength, and chemical microstructure. Four finite element models were developed to conduct a linear-elastic analysis to assess the effects of changes in structural integrity which may have occurred due to structural member modifications. A load test was performed to validate the models. Results confirmed the load path and the effects of modifying members as an initial assessment towards a complete safety analysis. The research also exposed gaps within current standards and provided a guide to future engineers on structural interventions in heritage structures as standards are developed.

This article deals with the restoration of the wooden frame of the Notre-Dame de Paris Cathedral as part of a scientific project after the 2019 burning. The purpose is to conserve the architectural heritage while ensuring the craftsmanship of the medieval age as described in [1], by Thibaut, Caré and Maurin in 2022. In this context, we have reproduced a part of the timber frame on the basis of the original schemes of the nave. Through an in-situ monitoring, this structure represents a study case in order to provide data relative to the kinetics of displacements of this structure composed of green oak. These informations allow to evaluate the global behaviour of the structure and its vulnerability by taking several deformability sources into account. A numerical bar model has been developed by using finite element software, like in the article [2] by Vannucci. P in 2021, to analyse the sensibility of material properties and geometry with data identified experimentally. We have also performed a retro-analysis focused on the axial stiffness of each connection in the model, by fitting data to reproduce the real displacements measured from static tests realized on the wooden frame. Similarly to the full scale tests performed on the article [3, 4] or [5], from full scale tests in-situ, we examine the effects of static vertical forces involving bending moment of the principal beams and including the influence of the scale factor and the global effects of this traditional timber frame. Furthermore, we carried out an experimental campaign consisting of tryout press on different traditional types of joints. The goal was to characterise their stiffnesses and their specific failure modes using images correlation like in the article [6] by Koch and Eisenhut in 2013. Concomitantly, numerical simulation are developed in order to investigate the dependence of the stiffness with contact gaps between the pieces, which is relative to the know-how of the carpenter and moisture content variations.

The ruins of the Kfar synagogue are located inside Bar’am National Park, in Northern Israel, near the Lebanon border, once part of an ancient Jewish village inhabited from 200 B.C. to Middle Age. The synagogue dates back to the 3rd century A.D. and was built using stones elements from pre-existing Roman-Byzantine public buildings. The building was heavily damaged by the Galilee Earthquake in 1837, which caused the collapse of the roof and part of walls and columns. Nowadays the ruins include 4 columns of the front porch, the main façade complete up to the second floor and part of inner walls and columns, while the entablature is almost completely collapsed.Considering the important historical value of the entablature - a unique example in Israel - the Bar’am National Park Authority decided to start historical, architectural, and structural studies with the aim of restoring its remains, planning to reconstruct the ancient front porch by anastylosis. The structural behavior of the remains has been analyzed through the Distinct Element Method (DEM), introducing the anastylosis reconstruction of the entablature to predict the seismic response of resulting structure. The stone elements have been modelled through rigid blocks and non-linear deformable interfaces; dynamic analysis has been performed based on local standard spectrum and accelerograms compatible with the seismological history and site soil condition.DEM simulation allowed to evaluate the seismic behavior of the reconstructed configuration, evaluating the opportunity of i) using monolithic or multi-drum new columns for the bearing of reconstructed entablature and ii) introducing connections between stone elements, addressing the design phase.

The dynamics the Santa Maria Annunziata church located in Camerino (Macerata province, Italy), subjected to transversal dynamic loadings has been analysed by using a distinct element code which implements the Non-Smooth Contact dynamics method. Since the contact between blocks is governed by the Signorini's impenetrability condition and the dry-friction Coulomb's law, the church exhibit discontinuous dynamics. The sliding motions of blocks are non-smooth functions of time. Numerical simulations are performed with the aim of investigating the influence of the friction coefficient and of some past retrofitting interventions on the global response. The results obtained are compared with the real damage that the Church suffered following the seismic sequence in central Italy in 2016, and for this reason the four main shock that strocked the area were used in the numerical analyses. A good agreement between the numerical and the real damages are finally obtained but it might be interesting to elaborate additional models in which the building presents different degrees of connection with the towers.

On the hills of some Andean cities in South America, the population has built their homes on terraces supported by traditional dry-stone retaining walls (“pircas”) without any regulation or code. Because this zone is prone to strong earthquake ground motions, it is necessary a better understanding of the pircas’s out-of-plane behavior and collapse mechanism for risk prevention and mitigation. However, no dynamic studies of this traditional construction exist to date. This work addresses a numerical study of the response of pircas subjected to ground motions in the out-of-plane direction and how different construction techniques (i.e. block arrangements and wall configurations) can affect this response. The dynamic analysis was carried out with the YADE (open-source software for discrete numerical models and focused on the Discrete Element Method, DEM). By varying the vertical separation of Through stones (tie stones) and overlap of stones in the cross-section of the walls, we obtained 5 models which were subjected to a representative seismic signal. Regular and parallelepiped clumps (groups of rigidly joined spheres) were selected for modeling the wall blocks due to their versatility in their geometry and lower computational cost than other types of particles supported by YADE [1]. The effect of the backfill has not been considered yet, since we are focused on the wall configuration effects on the dynamic response. In the absence of dynamic experimental results, the precise calibration of the numerical model has yet to be sought. The results obtained are preliminary. At a later stage, an experimental dynamic test will be carried out, and they can be properly calibrated. The numerical results showed that when the wall presents a cross-section with adequate overlap, the amount of Through Stone (from 2.2 to 3.6 per m2) is not important. On the other hand, when the wall cross-section has no overlap, the wall presents the least resistance to moderate damage levels and collapse. Additionally, it was possible to verify that the pseudo-static out-of-plane response (obtained in a previous study) is more conservative than the dynamic one.

The Fifth Minaret of Heart, part of the “Musalla” complex, 15th century, is the only one still standing in the Gawhar Shad area. The 42 m tower, whose external surfaces were completely covered by glazed tiles, used to corner the Madrasa, which was demolished at the end of the 19th Cent. This fact, coupled with several low-intensity earthquakes and recursive floods, has induced increasing leaning for over a decade starting from the end of the 80s, and the formation of an extensive crack at the base of the shaft. An emergency intervention carried out in 2003 prevented the collapse.The study pointed at a broad, multi-discipline knowledge path to systematize available information and determine the intrinsic material characteristics, the building technology solutions, the damage and vulnerability sources, the behavior under dynamic loading and the structural response in the current configuration.To determine the material characteristics, the following tests were carried out: uniaxial compression and indirect tension tests on bricks, penetrometer tests on mortar joints on site, porosity tests on bricks, X-ray diffraction tests and observation of thin sections at the optical microscope in polarized light on bricks and mortars and clay mineral composition. The building technology solutions were inspected at the site and supported by the analysis of borescope images. A seismic network composed of five seismometers was installed to implement Operational Modal Analysis. Results were exploited to calibrate the mechanical properties of the 3D solid mesh of the Minaret, retrieved by the Terrestrial Laser Scanner survey, and a set of modal pushover analyses were employed to determine the expected damage areas in the current configuration.

The Palacio Pereira, located in Santiago - Chile, is a historic masonry building that was severely damaged by the March 3, 1985 (Mw 8.0) and February 27, 2010 (Mw 8.8) earthquakes. This building was declared a National Monument in 1981, and its restoration began in 2016 after more than 30 years of complete abandonment. The seismic upgrade process included the repair of the existing structural damage and the execution of strengthening strategies to improve the seismic performance. In this context, this paper presents a brief description of the main works aimed at returning structural integrity, as well as the strengthening interventions carried out to improve the future seismic performance. In addition, the main results of an in-situ experimental campaign, aimed at identifying modal parameters from the response to ambient vibrations, are presented and discussed. Finally, a 3D Finite Element (FE) model of the building is updated by modifying the density and Young modulus of masonry to improve the matching between experimental and analytical frequencies. Results show that the new floor system provides a certain degree of diagram constraint.

The San Francisco de Assis church of Marcapata is a historical rubble masonry with mud mortar structure built between XVI and XVII centuries, located in the province of Quispicanchi, Cusco-Perú. Despite the importance of this monument, structural studies for its conservation and preservation are unknown. Those facts have motivated the realization of this study, with the objective to obtain data for the assessment of its actual structural condition. The paper begins with a brief description of the historical aspects of the Marcapata site and the Church, followed by the on-site structural inspection both at the exterior and interior of the monument. Based on in-situ non-destructive approach, Operational Modal Analysis (OMA) tests was further developed with reference to a representative wall of the monument. The results of the experimental field campaign were used to develop calibrated finite element models of the wall, and to indirectly estimate mechanical characteristics of the masonry. The initial structural inspection revealed the precarious state of conservation of the monument and the need for more detailed studies. Three-ruble-stone-mud-mortar wallets of 60 × 60 × 30 cm3 (height × length × width), made with materials like the original, collected around the site, were subjected to uniaxial compression monotonic load. A maximum compression resistance of 0.82 MPa was obtained. The dynamic properties of west wall of the church were identify through OMA tests. Three highly sensitive piezoelectric accelerometers and a data acquisition system were used. A fundamental frequency of 3.1 Hz was obtained using the enhance frequency domain decomposition approach. OMA tests also allowed to indirectly estimate a modulus of elasticity of 720 MPa for the masonry. The results obtained in this preliminary study will be used in the ongoing structural assessment of the Marcapata Church.

The need to safeguard and often restore the historical-architectural heritage has led over the years to the introduction of different types of structural reinforcements based on the use of fibres made of different materials capable of increasing the tensile strength of a given structural element. Such solutions are certainly valid in the case of seismic phenomena, while their behaviour in the case of another highly destructive phenomenon that can affect buildings is little investigated: fires. In the present paper, the behaviour of different types of reinforcements based on glass, carbon and basalt fibres, subjected to high temperatures was investigated. This work starts from some experimental data obtained through laboratory tests on suitably prepared specimens to build a numerical model capable of describing the evolution of the behaviour of these materials as temperature increases.

Masonry structures are built by laying brick or block elements, usually with mortar as cohesive joint, which results in its property that masonry is relatively strong in compression while weak in tension. Load capacity and the associated failure mechanism of a masonry wall or structure under lateral and vertical load depends on different parameters such as material (blockwork and joint) used, dimension of block elements and wall, different arrangement and workmanship of laying block elements. The historical center of Macau was recognized by UNESCO as one of the world heritages on 2005. Many of the historical buildings in this historical center were traditional masonry buildings in the south-east of China. Three types of masonry wall pattern, namely as the stretcher bond, Flemish bond and common bond, were commonly used in the construction of those masonry buildings. In this paper, the load capacity and the associated failure mechanism of these three different types of masonry wall pattern were investigated. Parametric study of these three different types of masonry wall pattern was performed by mean of limit analysis and Macro-block methods. The corresponding loading capacity results and failure mechanism obtained by these two methods were compared and discussed. It is found that lateral loading capacity for common bond and normal arrangement are smaller than Flemish bond. For Flemish bond, wall failed in sliding mechanism in the largest failure loading among these three patterns.

This paper presents a robust and accurate P-Delta Discrete Macro-Element Method (DMEM) formulation to assess the out-of-plane (OOP) rocking behavior of masonry walls, allowing for both mechanical and geometric nonlinearities with a limited computational cost. OOPs mechanisms are one of the main causes of failure or severe damage involving historical and monumental masonry constructions subjected to earthquake loading. These mechanisms can be activated at low-magnitude seismic actions mainly at the upper levels of masonry buildings due to the amplification of the dynamic response and wall displacements. In this paper, according to the DMEM, the wall is discretised in a number of shear-deformable macro-portions (macro-elements) interacting by interfaces allowing for flexural cracks and sliding at the joints. According to the proposed strategy, the equilibrium is imposed considering the system’s undeformed configuration, while the global load vector is computed at each step of the analysis according to the current position of loads. The model is validated against rigid-block numerical solutions accounting for large displacements and experimental tests. Finally, a real church façade is analysed, investigating the influence of the geometrical layout, boundary conditions, and masonry deformability on the structural response. The results confirmed the accuracy and efficiency of the model and its potential to be employed for real seismic assessments.

The conservation of the built heritage represents nowadays a great challenge for the scientific community and for the heritage managers since historical buildings can typically face both seismic and climate related hazards. To increase the resilience and reduce the vulnerability of historical constructions, specific strategies and methodologies should be developed and applied. In the framework of the Shelter project, funded by the European Union’s Horizon 2020 program, the Church of Santa Croce in Ravenna (Italy) was taken as a case study for the validation of such methodologies, involving a multidisciplinary approach. In this work, the structural behavior of the Church of Santa Croce was investigated through the development of a finite element model and the implementation of a Structural Health Monitoring system, with the possibility of accessing data in real-time. First, the historical analysis of the construction and slightly-destructive tests were carried out to investigate the constructive details, the state of damage, and the mechanical properties of the materials. After acquiring a detailed knowledge level of the construction, modal analyses and nonlinear static numerical simulations were carried out to assess the modal parameters and to reproduce the existing crack pattern. On the one hand, the numerical analyses supported the design of the monitoring system itself; on the other hand, a model updating was carried out to calibrate mechanical parameters not explicitly obtained through testing. The adopted methodologies and approaches are described in the paper, together with the results of the numerical simulations and preliminary results acquired from the monitoring system.

While understanding the shear strength of stone masonry structures is important for the design and the maintenance, we still lack computational tools for predicting the strength as a function of the stone layout. Here we implement an end-to-end image based kinematic analysis framework that converts the image of a stone layout of a wall into a 2D kinematic model. Machine learning and image processing techniques are applied to convert a wall image into a rigid block model, which is then used as the geometry input for an existing limit analysis approach using mathematical programming. This existing approach is extended such that also cohesion, limited tensile and compressive strength can be considered in the point-based formulation of interface failure. We apply the method to simulate the strength of stone masonry walls with mortar that are subjected to shear-compression loading and show that our method can demonstrate the influence of the stone masonry typology on the shear strength.

Sequentially Linear Analysis (SLA) is known for robust and reliable finite element simulations of masonry constructions, often considered challenging because of the brittle behaviour of the masonry material. Herein a sequence of scaled linear analyses is performed with decreasing secant stiffness of one integration point per analysis, representing local damage increments. This procedure is especially suited to simulate highly nonlinear collapse mechanisms. In this article, a benchmark experiment on structural historical masonry is first chosen. This benchmark is simulated using SLA, using the micro-modelling approach, with linear blocks/bricks and nonlinear interfaces using a multi-surface interface model. The results are compared against those of the experiment, nonlinear finite element analysis, and the Discrete Element Method (DEM), good agreement is found with those of the experiment, and the collapse mechanisms are also captured in a robust manner.

Fracture properties belong to one of the most important properties of wood due to its safety consequences that come out of the wood cellular structure and natural phenomena occurring in wood such as cracks. Cracks in wood may substantially decrease mechanical performance of wooden beams because they create stress contraction spots and, therefore, they should be studied with appropriate attention. To test fracture properties of wood, one can employ many techniques and tests. Specific testing procedures have certain requirements on specimens with respect to wood nature – grain angle, moisture, species and others. The general goal of this work is to analyze so called end-notched flexure test in three-point bending (ENF-3PB) scheme to provide fracture behavior of wood using such a test. The work consisted of utilizing 3D finite element analysis (FEA) to analyze sensitivity of testing procedure to various variables introduced to a specimen such as span-to-height ratio, friction coefficient and length of initial crack. The analyses considered wood as orthotropic material including both elastic and plastic regions of deformation using Hill’s plasticity. The crack path is modeled using cohesive zone models, contact between specimen and loading grips and supports was modeled using contact algorithms. Results show that ENF-3PB test is very sensitive to setup and in case of cumulative effect of studied phenomena, the measurement error might not be negligible.

Historic masonry structures form an important part of the world’s collective cultural heritage. Many methods have been developed for assessing the load carrying capacity of masonry gravity structures, from simple hanging chain representations to much more complex non-linear finite element models, though tools that can provide rapid and reliable assessments are still sought after. Here, a new automated procedure, termed thrust layout optimization (TLO) is presented. This is designed to overcome limitations of the traditional thrust line method, and more recently developed computer based alternatives such as the thrust network analysis (TNA) method. The new procedure is capable of automatically identifying admissible thrust lines in masonry gravity structures comprising general arrangements of masonry blocks, without the need to specify in advance the form of the thrust line or thrust network layout. As well as providing a rapid assessment of load carrying capacity, the TLO method provides a clear visual presentation of load paths. Also, sliding friction can be accounted for and large-scale problems involving complex geometries can be tackled, as demonstrated via various examples described in this contribution.

Peruvian construction technology has an original tradition of thousands of years, from a completely indigenous remote past to the cultural mixture of the viceroyalty centuries and the encounter with the rest of the world. This tradition has been, as is to be expected, strongly conditioned by the material characteristics of the geographical, climatic and territorial environment, with multiple adaptations and innovations. One of these innovations is the quincha, used throughout the coast of the Peruvian viceroyalty for the second and third levels of all structures. But the documentation indicates the use of a variant, the “double quincha” as an element that, using the width of more rigid supports, created an internal air chamber. This work references colonial and contemporary documentation and case studies in Lima, to verify the properties for thermal comfort of the double quincha, in one of the first studies of its kind for this material. Architectural surveys and systematic temperature measurements were carried out at multiple buildings in the center of the historic city- as well as the use of models in an energy simulator program. The results allow us to understand a little more both the constructive reasoning of quincha and the possibilities of this traditional method.

Qīujiā Zhàcaì Zuōfang was a vernacular building cluster in East Sichuan Basin of China with a history of more than a century. A Siheyuan quadrangles of the cluster, called as Shàngyuàn, was alternated and finally demolished after mid-20th century. The aim of this research was to define and reason the status of Shàngyuàn after its original finish and before demolition. As a result of this research, the history of the building cluster was first clarified. Architecturally, the historic length measurement system adopted to construct Shàngyuàn was defined, and the original architecture of Shàngyuàn around 1900s and before demolition were reasoned.This research was an application of existing study and theory about the vernacular buildings in Sichuan Basin and showed a methodology to verify historic building archives for built heritage conservation projects. It also provided a feasible approach to reason original building for the remains of Szechuan vernacular buildings, especially for those lacking reliable archives or photos.

The urban landscape appears as a synthesis between perspective, recognisable shapes, and repetitive and interpretable details. The connection between urban planning, built heritage, and the preservation of urban landscapes and historical building techniques represents one of the most important components when approaching new urban developments in historic areas and interventions in heritage buildings.Based on this, a study was conducted in Timisoara, Romania, a city with a wide variety of heritage areas. Despite this, there have been a series of difficulties regarding the protection and management of these sites, one of the main causes being aggressive new developments in/close to those sites, leading to the loss of highly valuable buildings, but also complex historic construction techniques. Regardless of these interventions in heritage areas, roof structures in Timisoara tend to be overlooked, leading to intact roofscapes around the city.Therefore, taking into account that the roof, not just as a part of a building but as an element of the urban landscape, the study highlights that all elements are interconnected, and none can be approached without taking the others into consideration when developing proper management plans for heritage buildings and historic urban areas. In addition to this, context-related decisions taken in the past also affect the general layout of the roof structures ultimately influencing the considered joined details.

Many countries are facing a drinking water crisis today, and many governments and NGOs are deriving new sustainable water supplies, ensuring quantity and quality. Aiding this, water infrastructure experts are also exploring the revival of traditional water systems and methods to address scarcity, especially to support societal traditions and cultural resilience. While protection of catchments and sources, recharging water tables and strengthening the role of communities-ensuring access and managing water are emphasised in the current conservation and revival strategies, a water system's most prominent and tangible component, i.e. access and protection structure itself, requires in-depth study to address present restoration challenges. A lack of understanding of the structure and construction of traditional water storage bodies as a product of multi-layered knowledge of topography, geology, hydrology, soil types, local contexts, etc., coupled with the linear and standardised approach, is yielding undesirable and unsustainable results such as inappropriate restoration of the structure, thus compromising structural and material integrity and heritage value. Hence it becomes critical to address this problem with a multidisciplinary technical understanding of excavation, structural and construction systems that have been used to build these architectural marvels, perhaps beyond the craft skills and knowledge available today. The paper explores how the historic step wells were technically and skilfully designed and constructed, the structural and geotechnical considerations/constraints, response to local hydrology, transformed modes of water extraction and how reuse can serve modern local functional needs while preserving and celebrating the historic character and cultural heritage values.

The San Francisco de Oña neighborhood is in southern Ecuador and is included in the national heritage list. About 20% of the heritage buildings are in an advanced state of deterioration, mostly abandoned and without maintenance. This article shows the intervention in one of these vernacular heritage buildings through a so-called Maintenance Campaign, which is an initiative developed by the University of Cuenca and is based on the recognition of values and the participation of different social and institutional actors through collaborative work, known as “minga” in the Andean world. The research was carried out based on two methodologies: a) the preventive conservation methodology according to ICOMOS 2003 and b) the participatory methodologies according to RedCIMAS (2015), which allow for active interactions and mutual learning among its actors. The University of Cuenca developed twenty maintenance projects in the San Francisco de Oña neighborhood, although due to the Covid pandemic it was only possible to intervene in one building. This case study turned out to be very interesting, because not only was a heritage building rescued utilizing traditional constructive techniques, but also an urban project by the Municipality of Oña was halted, which would have led to the destruction of part of this building by transforming a narrow dirt road into a wide road for heavy traffic. If this project had been carried out, heritage in Oña would have been affected in two ways. First, one of the buildings with the highest heritage value of this neighborhood would have been lost and second, a drastic change would have occurred in the historical cultural landscape of the San Francisco de Oña neighborhood.

During the 1990s, the Getty Conservation Institute (GCI) carried out a research and laboratory testing program, the Getty Seismic Adobe Project (GSAP), which investigated the performance of historic adobe structures during earthquakes and developed cost-effective retrofit methods that preserve the authenticity of these buildings. While the GSAP methodology was excellent and effective, it felt its reliance on high-tech materials, equipment and professional expertise was a deterrent to it being more widely implemented. To address this, the GCI initiated in 2009, the Seismic Retrofitting Project (SRP) with the objective of adapting the GSAP approach to better match the equipment, materials, and technical skills available in many countries with earthen sites located in seismic regions.The paper will analyze how the SRP was communicated and bought in by national and international stake holders, how high techniques analysis and low-key testing was combined to better understand the seismic performance of earthen sites, how the knowledge acquired in the process was disseminated among Peruvian and Latin American professionals, how two implementations’ projects were carried out and how a set of guidelines were adopted by Peruvian authorities.

2020 Zagreb earthquake sequence provided unprecedented opportunity to answer many unknowns and uncertainties in the understanding on earthquake performance of masonry buildings and to analyze many concerns affecting the post-earthquake assessment and renovation strategies in Croatia. These decisions are based on the updated knowledge obtained through the assessment. Condition assessment can be done on multiple levels, e.g. basic visual assessment of a structure, assessment with various destructive, non-destructive and semi-destructive testing methods, interpretation of a data from structural health monitoring, various levels of structural modelling and safety verification formats. Procedures mentioned are carried out to collect the data on several significant factors that affect the seismic behavior of buildings. The comprehensive data and overview on the seismic performance and management of masonry buildings after the earthquakes in Croatia can be used to test the effectiveness of existing models and to inform the development of new models for seismic risk assessment and resilience analysis. The condition assessment and renovation process of building of exceptional heritage importance will be presented and discussed. The value of information analysis presented for a case study building shows how additional information and acquired knowledge brings multiple benefits in retrofitting and management process.

The Industrial Heritage (I.H) is made of rests of the industrial culture with its historical, technological, social, architectural and scientific elements – parts of buildings, machinery, laboratories, firms, mines and locations where processing and refining procedures took place, warehouses and shops, energy production and transfer sites. Such electricity is used for transport and all its infrastructure as it occurs for places where social activities take place such as accomodation, training or religion worship facilities [1].The patrimonialisation process of the I.H. is essential as it recognises a community heritage made of memories and identity. The research is based on the Italian productive and vernacular patrimony, especially in the south of Italy, by taking into consideration the proto-industrial period – from the second half of the17th century to the second half of the 19th century – and analyses the organisation of the industrial system before the real industrialisation Era starting in the19th century.Italy is rich in working places, in fact, in southern Italy agribusiness has a great impact with its range of productive activities connected to agricultural products processing. Indeed, the milling vernacular industry represented an economical development source between the 17th and the first half of 20th century, this is the reason why there are lots of mills and bakeries for bread. The study deeply analyses the economic and social impact of water mills – vernacular and productive architectures of rural areas used to process wheat into flour. The “Val D’Agri” presents a large number of water mills and is located in the south-west part of Basilicata region. Its name comes from the river crossing the area. This analysis considers the functional recovery of watermills with a multidisciplinar criterion.

It is necessary to encourage the use of natural materials in construction due to the negative environmental impact of modern construction methods. Cane, or Arundo donax, is a grass reed that grows widespread across the world, in predominantly sub-tropical environments. Environmentally, the plant is invasive in most of the regions that it grows. Agriculturally, many farmers and landowners consider it a hindrance. Architecturally, with suitable skills and appropriate design, the material may be harvested and used to form lightweight, resistant, structural elements, namely catenary arches, for use in temporary, permanent or existing structures. As little research exists on the use of canes in arches, an experimental campaign was proposed.An initial material characterisation was carried out using the ISO22157-1 standard for bamboo, as cane standards do not yet exist and the plants are part of the same family of grasses, possessing similar geometric and growth characteristics. Weekly moisture content values were collected to check their variability over time. Compression parallel to the fibers values were determined and subsequently, the compression modulus.For the structural testing, three catenary arches of the same size were constructed by the “Canyaviva” method, using hands, tools and rope. This was achieved through the organisation of a workshop attended by members of the academic community.Once built, full scale tests were carried out using a steel frame loading apparatus, and the arches were loaded until failure. LVDTs were used to determine the deformation at specific locations and visual imagery was analysed for arch behaviour. Results provided strength capacities and collapse mechanisms of the arches.On a local level, it was concluded that the mid-section of the culm exhibits higher load resistance, and older culms resist load better than those with younger maturity. The material possesses a high moisture content that is dependent on surrounding environmental conditions. On a global level, when formed into an arch with a suitable configuration, the material has the capacity to resist up to seventeen times its weight, while maintaining a lightweight and flexible nature.

The structural restoration of the heavily degraded combined wrought iron and cast iron orangery of the castle Hof ter Borght at Westmeerbeek, Belgium, proved to be a challenge. This paper presents the problems encountered and the suggested interventions.The assessment of the condition of the construction was difficult because of the very extensive plant growth in and on the orangery, which had broken nearly all the glass panels of the roof and walls and covered most of the wrought iron and cast iron elements. During the disassembly of the structure, the weakened connections between several elements suffered unavoidable additional damage.Microscopical and chemical analyses indicated wrought iron and cast iron of low quality for several elements, exhibiting impurities and air pockets. The mechanical characteristics of the historical wrought iron and cast iron were determined by tensile and compression testing. A finite element model of the orangery is used to analyse the stresses in the structure, assuming an intact structure at first. Secondly, additional modern steel elements are added to support the weakened structure, along with the strengthening of the connections themselves. Several options for reinforcement of the cast iron connections are suggested and compared, ranging from recasting entire elements to bolted steel overlapping plates. Furthermore, the feasibility of local epoxy polymer filling for column feet anchorage and other epoxy prothesis applications for cast iron connections is assessed.

Most studies use historical approaches to studying castles based on historical descriptions. By contrast, this paper proposes the knowledge domain based on comprehensive research that includes compositional analysis of historical plans, natural lighting analysis of the initial built plan and its comparison with the current state, and analysis of space morphology. Such a detailed approach will help to understand better the changes in the building that has occurred over time, highlight the main compositional elements of the layout that identify the building type, and represent its authentic value that needs to be preserved. As the case study, a bastion castle in Ukraine was chosen, Brody bastion castle, also called a citadel. The results show that former design of lighting access to the spaces in bastion castle in Brody has even outreached the high-quality models of residential buildings in Palladio Book II, where more than half of the buildings do not have direct access to all spaces.

The article presents the process of rescuing the Baroque convent of the monastery in Plasy found on oak raft and piles. Santini designed a water system to bring clean water to the clay basins under the monastery. This measure kept the foundation structure under water and ensured its preservation.In the 18th century, knowledge of the behaviour of the building was lost, the water pipes necessary for the stability of the building were interrupted and many inappropriate interventions were made. Santini was mindful of this possibility and proposed an emergency scheme whereby ambient water is drawn into the foundation pools. However, now this source of water did not meet the requirements for the conservation of the foundation structure.This paper describes the partial repair of the water supply and evaluates its impact on the building by comparing the indoor microclimate before and after the repair, including the possibility of drying the indoor air in the building by spraying cold spring water, which in the past was provided by a baroque fountain.At present, the positive effect of the repair on the monastery’s foundation structure and the improvement of the indoor microclimate in the convent building through the spraying of cold water by fountain are evident. The tracking test has identified the connection of the parts of the water system and the division of the foundation water basins into independent units. Chemical analyses confirmed the suitability of the new water source for the foundation system.

The article deals with interventions in the Moorish Pavilion or Moorish Castle in Manguinhos, in Rio de Janeiro, main monument of the architectural complex of the Oswaldo Cruz Foundation – Fiocruz, one of the most significant and symbolic architectural ensembles in Brazil. It is the headquarters Fiocruz, under the supervision of the Brazilian Ministry of Health, the most prominent institution of science and technology on health in Latin America. It was protected by the National Historic and Artistic Heritage Institute (IPHAN) in 1980. The construction of the complex started in 1904 and the construction of the Moorish Pavilion started in 1905. It was on the initiative of the renowned Brazilian scientist Oswaldo Cruz and was designed by the Portuguese architect Luiz Moraes Júnior. The Moorish Pavilion, adopted the eclectic language and received the most varied influences of monuments, styles and decor: Montsouris Observatory (Paris, France), English railway stations, Elizabethan architecture (England, second half of the 16th century) and Moorish architecture (Iberian peninsula, 11th–15th centuries, especially Alhambra Granada, Spain),An architectural reading of the Moorish Pavilion will be made, examining the architectural language adopted; the material and building systems used in its construction; its meaning for the city and the heritage designation process, the surrounding environment in various periods, and the physical, functional and visual relationship with the city. Regarding the restoration works method, the following will be examined: causes of deterioration, diagnosis and state of conservation, interventions performed over the years, the project and methodology of the latest intervention. In the conclusion, the article will analyze the interventions undertaken in the light of the modern principles of cultural heritage preservation, the importance of the restoration works of the Moorish Pavilion Manguinhos, and its use as a public cultural and scientific space for the city.

The Gillender building in New York, constructed in 1897 and demolished in 1910, was the most slender steel-frame building constructed in the US before World War II, and was the among the tallest modern buildings when constructed. It is a good example of the best design practice of the first generation of steel-framed skyscrapers, and as such provides insight into the frames of those buildings. In short, did the frame design make sense by modern standards? Steel-beam design from the 1890s is generally acceptable today, although slightly over-conservative. However, column design and frame analysis have changed much more than beam design in the last 120 years, and portions of the original design do not meet basic criteria of modern codes. There were no structural problems, excessive movement, or signs of overstress reported during the building’s (admittedly short) life, which suggest that it was empirically competent for some level of loading. This paper compares original and modern analysis, and reviews reasons why the building functioned better than modern analysis suggests it would.

Two general approaches in concrete heritage preservation can be distinguished since the 1980s. Both have been met with approval from the official preservation authorities in German-speaking countries up to the present day. However, regarding the conservation of material substance and appearance, they are diametrically opposed and differ strongly regarding continuous reparability, reversibility, and monitoring.The following re-assessment is based on a historic analysis of the formation of the two approaches, which were for the first time widely discussed on the repair of the Antoniuskirche in Basel (repair 1987–1991) and the Liederhalle in Stuttgart (repair 1991–1993) respectively. The latter has been acknowledged as a best practice example for localized repair and careful preservation, whereas the first has been discussed as an exemplary case for renewal with imitation of the original surface appearance. However, as revealed trough a recent in situ condition survey and accompanied archival research, this one-sided perception has so far lacked to consider the diversity of the actual repairs.After about 30 years, we re-evaluated the two prominent cases of early concrete repair in heritage conservation to discuss the appropriateness and suitability of the approaches and their long-term consequences, also in light of the comprehensive contemporary discussions. Based on an ongoing DFG-funded research project, the paper points to new methods of systematic photographic survey and color measurement for the examination of repaired concrete surfaces, which are highly relevant for their assessment, monitoring and thus for future decision-making processes.

For the time being, there is a considerable amount of abandoned, historical buildings worldwide which are sadly distinguishable owing to the progressive state of dilapidation they are in. The primary reason for which these valuable constructions are forsaken is the absence of monetary funds that would naturally allow for their long-term maintenance. Ordinarily, the owners of these proprieties do not have such substantial financial reserves, which impedes the conservation or extension of the buildings’ lifespan. Nevertheless, the local authorities of some countries have devised numerous coherent policies through which they minimized the extinction of listed buildings. The present article introduces a particular and original strategy to rescue a grouping of Grade II listed buildings in Preston, United Kingdom, and restore their potential of being community beacons [1]. The architectural adaptability and conversion potential of these constructions have been rigorously examined in parallel with the community’s needs. So far, the collection of buildings has represented a social danger for the residents of Preston being gradually obliterated by the passage of time and exposure to damaging weather conditions. The access on site has been restricted for decades which inconsolably led to a faster physical degradation and an accelerated sense of oblivion among locals. Beside the regenerative quality of the proposed architectural solution, the initiative also encompasses a variety of benefits for the local inhabitants. If the buildings formerly operated as an orphanage for abandoned roman-catholic girls, a chapel, and a community ward, the new proposal champions an architecture that promotes shareability through a series of internal and external facilities which will serve the local and wider community. Therefore, the article will demonstrate that consolidation is not the singular option to reinstate a historic structure, but when perceived from a multidisciplinary perspective, it can yield successfully developed schemes where the viability of a physical form is complemented by a preserved architectural language.

In view of the pressing need for strengthening old masonry structures, while considering the importance of reducing CO2 emissions in the construction sector, masonry retrofitting techniques with environmentally friendly (i.e., non-cementitious and non-corroding) materials need to be studied and developed. This paper discusses the mechanical performance of historical brick single-leaf masonry elements strengthened with a textile reinforced alkali-activated mortar (TRAAM). Ferronickel waste slag was used as the precursor of the TRAAM matrix, whereas the textile reinforcement consisted of carbon fibers. The mechanical performance was determined experimentally on the basis of diagonal compression capacity of wallettes. Apart from normal conditions, the mechanical properties were also determined after fire exposure. Two fire tests were performed, with a high heating rate in the first stage, a steady-state stage, and a cooling stage. The maximum temperatures reached at the TRAAM overlays were in the order of 300 ℃ and 550 ℃, respectively, for the two tests. The results showed a significant increase in the shear capacity of the strengthened walls compared to non-strengthened ones, in ambient conditions. Fire exposure of the strengthened specimens did not lead to a decrease of the shear capacity compared to the unexposed strengthened specimens. This was attributed to the superb fire performance of the ferronickel slag based TRAAM.

The protection of heritage values manifested by historical structures under pressure of ever-expanding ideas of modernisation, driven by development requirements and new technical needs, presents a continuous contemporary challenge. Railways as heritage present a very specific challenge. Often referred to as socio-technical systems, their economic and safe use is essential to safeguarding their continued existence and by extension their heritage value. Railway infrastructure also often passes through cities and landscapes with heritage value. New social needs and technical changes encourage authorities to introduce new techniques or even to implement complex reconstructions in historical railway structures such as viaducts, bridges and tunnels or even their surrounding urban elements. A lack of (inter)national protection can lead to an irreversible loss of heritage values when authorities and stakeholders do not see benefits in the protection of historical and cultural attributes.In this chapter, two cases will be presented: the challenges posed by the infrastructural upgrades required for the operation of the historic Rhaetian Railway in the Albula/Bernina Landscapes World Heritage property in Switzerland/Italy and the demolition for reconstruction of the historic nineteenth century Grzegórzecki Viaduct in Kraków, Poland. It will present the special dilemmas posed by the maintenance of railways heritage as operational systems and reflect on the personal experiences of the authors with these cases, concluding that, while in a technical sense, much might be possible, standardized solutions are not appropriate to valuable in-use heritage rail infrastructure.

The paper presents the results of preliminary tests of a newly proposed Fiber Reinforced Polyurethane (FRPU) composite system with mineral interlayer for strengthening of heritage structures in seismic areas. The analyzed FRPU system consisted of strips of an unidirectional textile of Ultra High Tensile Strength Steel (UHTSS) cords embedded in a two-component highly deformable polyurethane. In the tests a layer of composite was applied to clay bricks covered with 6 mm-thick layer of hardened mortar. In this research two types of mortars were considered: a lime-based mortar and a cement-base one. The specimens were tested in a single lap shear test (SLST). The presence of mineral interlayer resulted in reduction in shear bond strength of the composite to brick when compared to reference specimens without mortar layer. The tests results indicated that the use of mortar layer did not significantly modify shear stiffness of the connection between the FRPU strengthening system and clay brick substrate. The results of the tests shown that the tested strengthening system seems to be an effective and reversible solution for strengthening of heritage masonry structures.

Sighișoara Citadel, listed as world heritage site since 1999 under position 904, has been the object of many research studies and analyses. Sighișoara is an important tourist attraction due to its valuable built heritage and to its potential connection with Vlad the Impaler. The fortified area occupies around two thirds of the hill and is made up of a higher plateau dominated by the evangelical church and a lower plateau occupied by the medieval settlement. The medieval fortification includes both plateaus, walls, and towers. From the originally 14 towers, nine towers have been preserved. They are slightly changed, but still in use today.The last research dates to 2020–2021. It consisted of modern recording, investigation methods intended to review and supplement the previous studies and assessments.This paper is focused on the comparative analysis of the remaining nine tower structure, on the processing of the results of the new research on the roof and other timber structures, and on the analysis of the previous interventions. Moreover, the paper is focused on drawing the attention on the exceptional values of the historic load-bearing structures, and on the possibility to extend the analysis methodology to other towers in Transylvania.The tower load-bearing structural systems consist of load-bearing walls in stone, brick, mixt masonry, vaults, and oak beam slabs. The roof structures with or without defence level are medieval structures of oak with one exception, which already bears the mark of Transylvanian Baroque roof structures.

The development of reinforced concrete through the 20th century has resulted in a wealth of historically and culturally significant concrete structures around the world. However, the durability and deterioration mechanisms of this new material were not well understood and, as a result, many historic reinforced concrete structures require ongoing maintenance and repair. Patch repairs are common during repair campaigns. However, balancing traditional conservation principles, such as minimal intervention and retreatability, with the best practices of contemporary concrete repair and the need to provide repairs which do not affect the historic aesthetic of the structure can be challenging. Three institutions, the Getty Conservation Institute (GCI), Historic England (HE) and Laboratoire de Recherche des Monuments Historiques (LRMH) are collaborating on the research project, ‘the Performance Evaluation of Patch Repairs on Historic Concrete Structures (PEPS)’, which aims to provide guidance on this issue. Over the course of the project, historic structures in the USA, France and England, which have been repaired previously have been assessed. This paper presents a comparison of the preliminary results from two case studies from England and discusses the different repair approaches that were implemented.

When subjected to earthquakes, some objects or structures can behave like rocking rigid bodies. Statues, ancient columns, computer servers and electrical equipment are frequently included in this category. Conservation of these objects can be a crucial task, due to their tangible and, at times, intangible value as well; base isolation technology has been proven to be a viable option for this purpose.The dynamic model of a rocking rigid block placed on a base isolation device is summarized here. Then, a displacement-based procedure to design this type of protection system for rigid rocking bodies is proposed, and the main steps are illustrated. The procedure aims to determine the characteristics of the isolator to prevent initiation of rocking motion during the design earthquake.The proposed procedure is successively validated by examining the dynamic response of the system to a suite of a spectrum compatible accelerograms. To this end, the minimum analytical period of the isolator that prevents rocking motion (identified using the proposed procedure) is compared with that obtained using time history analysis. The results highlighted the sensitivity of the system to the input records. Successively, a suite of accelerograms scaled to match the design spectrum at the analytical period of the isolator is used for validation. In this case, the efficiency of the proposed design method is demonstrated. The presented displacement-based procedure appears applicable for the preliminary design of the isolators, and the no rocking approach seems particularly suitable for small size objects.

Measurement models are a special type of model used in the field of civil engineering and architecture to analyze, understand, dimension, and test load-bearing structures. Like architectural models, they served as a communication medium and planning tool but were often damaged or destroyed in the measuring process. Consequently, only a few models have survived or found their way into collections. After the models had been elaborately produced in highly specialized workshops and tested by specially trained engineers, they fulfilled their purpose as tools and were dumped or kept as objects of a purely commemorative nature for as long as space permitted. The experimental equipment and testing facilities continued to be used for other tests so that the kept objects can be seen as mere fragments of their actual function. Since the potential of these fragments was not recognized until it was far too late, some of these objects have taken interesting paths in their preservation history, such as the measurement models for the Olympic roofs in Munich by Frei Otto or a test shell for the design of a concrete shell by the German shell builder Ulrich Müther. The preserved objects are repositories of knowledge about the design process. In the research project “Last Witnesses”, founded by the German Research Foundation in the Priority Program “Construction as Cultural Heritage”, the fragments are examined from the perspective of construction history and were digitally rebuilt for further research on the use and purposes of these objects in architecture and engineering.

The Lazzaretto Vecchio (hospital for the isolation of plague patients from 1423 to the XX c.) is an island located in the central lagoon of Venice, preserving a historical-monumental heritage of primary interest. Around the mid-nineteenth century the island was used as a military warehouse, and part of the built heritage was demolished. Restoration interventions date back to the late 1980s, the 1990s, and the first decade of 2000.With the aim of creating the “National Archaeological Museum of the Venetian Lagoon”, a masterplan was developed for the whole island including other cultural uses, eventually funded with € 11 million in 2020 (FSC 2014-20). Accordingly, in 2022 a wide investigation campaign (crack pattern survey, sonic & ultrasonic tests, borescope inspections, flat-jack tests, timber visual inspection, densitometry and humidity analyses, dendrochronology) took place, aimed at defining the structural features of the buildings. The structural analysis was then carried out, outlining in several positions – together with on-site tests outcomes – a precarious state of conservation and compromised safety conditions. Related restoration guidelines were then approved to support the definition of the detailed restoration design, currently ongoing.The paper will present the relevant site history and foreseen development, the outcomes of the investigation and structural analysis, the consequent design approach, balancing the structural safety with the required conservation issues.

The Cosmic Ray Pavilion is a double-curved concrete shell built in 1951 located in the National Autonomous University of Mexico, by the Spanish architect Félix Candela Outeriño, according to the Master Plan of the University City, which is currently listed as Heritage Culture of Humanity. The Cosmic Ray Pavilion was a project designed as a construction-machine, since its objective was not to be inhabited, but to house a series of equipment that would oversee monitoring cosmic radiation, and for its operation a surface with a minimum thickness of 15mm in its centre (where the machine would be positioned), which was constructively difficult for the technological advances of the time. (1951). Over time, the use of the space was modified, the original structure was altered, and adequate maintenance was not carried out on the envelope, which has caused the deterioration of the property. The evolution of the design proposal, the technical details of its execution and the challenges of the construction system were studied to know the current situation of the concrete shell through non-invasive techniques. The results obtained from the study of the structure of the Pavilion contrast with the information from the archive of the National Autonomous University of Mexico. The importance of non-invasive analysis methods in construction systems is discussed, to know the current situation of buildings, and generate intervention strategies that preserve the built heritage of humanity.

Romania hosts a large number of historic buildings. Some of them are listed as historic buildings of various value, value group A for national value, value group B for local value, and some of them are even included on the World Heritage List. The historic building protection has lacked continuity and was only resumed after the 1989 Revolution. Therefore, many historic buildings are severely decayed, have been subject to unauthorized interventions, and even to interventions conducted by non-specialists. While the historic buildings on the UNESCO List or of national value are approached with big care, benefit of funds for all planning stages, the historic buildings of local value or non-listed are in real danger. The hidden parts such as roof structures are even less considered when their value is minor.This paper analyses the interventions on a historic roof structure dendrochronologically dated back to the 1720s belonging to the church of the Bulgarian Franciscan Monastery. While applying the research principles for valuable historic roof structures, we also perform a theoretical analysis of several solutions for repairs and consolidation considering safeguarding the values, as well as of intervention implementation and efficiency based on analyses, tests, and structural modelling. This example may show how complex the reasoning when choosing a solution for repairs or intervention on 18th century timber roof structures.

Introduction: A good old engineer used to say, “If you want to find the essence of a thing, put down the magnifying glass and first go as far back as possible to see what the environment near and far was and is like for that thing. If you understand the context, you are ready for detailed research.” The topic of the paper is an excuse to discuss the breadth of the spectrum of impacts important to historic buildings, structures and their elements. Is it possible to define them all? How should a failure analysis be conducted to predict what impacts will result from repairs and what resistances should be designed? The answer is impossible and unreasonable without full knowledge of the conditions under which they were manufactured, built, how they were used throughout their lifetime, how they degraded over time and under what factors. Material and Method: 40 years of research and analysis of objects in the Medieval City of Toruń (listed as a UNESCO World Cultural and Natural Heritage Site), in constant contact with the rescue of monuments, is the place to collect materials and conduct analysis. To show how to approach the problem, four examples from recent years were selected. Selected elements of a frame building (wood, solid brick) from the turn of the 20th century, two masonry buildings from the mid-19th century and a newer one from the mid-20th century were analyzed to show the problems of reinforced monolithic concrete. Buildings with a main structure of reinforced concrete are infrequent examples of a monument but have begun to appear more and more often in conservation practice. For the purpose of the analysis, specially prepared inventories of objects with some of the features taken from the conservation stratification were used. The inventories were supplemented with a structural stratification defining the time and type of technologies and materials used from the time of construction through subsequent renovations, alterations and repairs to the date of analysis. No less important was the examination of historical changes in atmospheric conditions, air, water and ground pollution, and the history of changes in the surroundings of the buildings.This procedure made it possible to analyze the facilities on five levels: - as physical, biological and chemical creations, - as places intended for human use, - as objects of long-term attack of environmental impacts, - as part of an ongoing history forcing changes, redevelopment, - as objects of impacts related to the maintenance of an operational or non-operational state.Results: In the presented group of analyzed objects, damages with common and unique features were found, occurring only in the studied objects. Most of the problems are due to human activity, and mainly to the cost and insufficient knowledge of those taking care of the monuments.Conclusions: The most important thing is the dissemination of knowledge and the creation of mechanisms that require adequate preparation from people in the vicinity of monuments. Also of utmost importance is an emphasis on expanding the required spectrum of research and analysis before taking action.

A heritage structure gives an insight of intangible cultural manifestation which emphasizes the past and communicates the opulence of knowledge and skills behind it to the next generations. Heritage structures are the living archetypal in the journey to the roots of native culture. These structures because of their age endure a lot of wear, tear, and environmental distress. Every structure behaves differently depending on its age and style of construction. So, it's imperative that we understand the present-day condition of the structure. Recognizing and catering to the health of the structure can prolong its life and in turn, we can preserve it for generations to come about our rich heritage. A structural health assessment for those parts of the structure which is not in breach of the common person can be done with the help of high-end technology. Today’s technology when trained congruously with experts can give faster and more precise results which can help in the restoration of the Heritage structure. An expert system that can analyze the present structure and give information about the location, severity of the damage, and accurate methods to improve the health of that damage is possible with the help of artificial intelligence and deep learning.

Diagnosis of historic buildings is relevant because it contributes to their preservation in adequate and safe conditions; in the present work, the Electrical Resistivity Tomography (ERT) technique is applied on horizontal and vertical planes to study aspects of humidity, to recognize the internal geometry of elements, and to detect resistivity anomalies in two old buildings in the state of Aguascalientes, Mexico; these buildings are the Temple of the Inmaculada Concepción and Terán House. In the first, the electrical profiles obtained from the subsoil show a zone of low resistivity associated with a saturated layer that damages the wall due to rising dampness. On the second, the resistivity images obtained from measurements on two walls with humidity problems show the source and define some flow patterns. It could be concluded that using the obtained results ERT technique generates valuable information for the preservation of built heritage and, therefore, is viable for the diagnosis of historical buildings, mainly in the study of humidity and discontinuities in walls.

Heritage buildings in high seismic hazard areas usually have high vulnerability due to many factors affecting their seismic performance, including material properties, construction procedures applied and preservation conditions. One especially vulnerable structural system used for thousands of years, is the one using compacted soils as a construction material, called rammed earth structure. As rammed earth walls dry and harden, material properties and strength increases. However, weather phenomena during time like storms, floods, ice and snow change walls water content and could change overall structural behavior if there is no protection covers over walls. The aim of this work is to analyze the influence of weather on the seismic performance of rammed earth walls. Water content profiles of two selected walls were calculated and evaporation flux was modelled from experimental data in reduced scale models inside a climatic chamber. After, a finite element model was used for computing dynamic linear and nonlinear performance of earthen walls subjected to selected strong motion records, in different weather conditions. Results indicated that wall shear modulus increase as matric soil suction increase, rising earthen wall’s stiffness in dry conditions, increasing vibration frequencies. Under different water content situations, wall’s stiffness change, vibration frequencies decay and seismic performance changes considerably. Nonlinear walls’ behaviour indicates variable differences between dynamic results under saturation and under residual dry conditions. Those differences will have considerable impact in the design, construction, strengthening or rehabilitation programs on rammed earth buildings, impact that has been neglected when considering earthquake resistance and vulnerability of heritage constructions.

The conservation of Modernism heritage is of utmost importance today since the concrete heritage of the 20th century is now aged and faces severe durability issues. However, due to restrictions introduced considering their architectural identity and aesthetics, the repair and conservation interventions should be performed only if the reversibility of actions is ensured. The design of repair patches and retrofit layers should be based on this principle and at the same time performed in long-term and often in aggressive environments, indicatively sea exposure. This work report on recent experimental tests evaluating the compatibility criteria that should be established in order to ensure durability and the optimal mechanical performance of cement-based fiber-reinforced repair patches for degraded concrete. The adhesion to the degraded substrate is of utmost importance since bonding should lead to efficient interaction among materials, however should not alter the substrate consistency and response to service loads. The deterioration mechanism of chloride-ions exposure leading to concrete carbonation and rebars corrosion is tested by evaluating large open cracks as formed after bending of small-scale concrete slabs. The retrofit layering is applied after the accelerated exposure of the slabs to the chloride environment and evaluated by cyclic bending tests that follow. The compatibility of the materials under flexural stresses is monitored using an integrated inspection methodology: acoustic emission and digital image correlation, whereas the adhesion of the retrofit to the substrate is inspected using microscopy scanning and ultrasound pulse velocity. It is demonstrated that premature interfacial debonding can be linked to the incompatibility of materials due to different stiffness and lack of interlocking. This phenomenon can be catastrophic for future rehabilitation projects.

Historic centers usually have a dense urban fabric and little availability of open public space. After the covid19 pandemic, this lack has become even more apparent. In this context, the communal flat roofs of the buildings can represent an important potential to improve the quality of life in dense historical centers. Specifically, in the case of Barcelona, the project in which this research is framed studies how to use them as space of care, meeting, and rest specially addressed to the increasingly aging population. Prior to any action of rehabilitation or modification of existing roofs, their characterization is necessary.This paper presents an in-depth constructive description of the existing roofs in the historic center of Barcelona, never been done before. The different periods of construction show different solutions present that are described in this analysis, detailing the materials originally used and quantifying the main properties of the typologies that influence their behavior. These solutions are georeferenced and quantified in the historic center as a whole. The main interventions usually carried out are also described and geo-referenced. Finally, guidelines and aspects to consider for its rehabilitation for future use are provided, also quantifying the available potential of community roof surfaces that could assume new uses as communal space for citizens.

The Document on Authenticity (ICOMOS Charter on Authenticity, Nara 1994) and the results of conferences that preceded it, offer a solid theoretical basis. The Document builds on the Venice Charter and emphasizes “cultural and social values”. It does not offer worldwide uniform procedures, but presents general criteria allowing their application and verification in different conditions respecting cultural diversity of the world's regions. Almost 30 years since the adoption of the Document, authenticity is still in the centre of interest in the protection of cultural heritage. Authenticity and Integrity are emphasized when assessing the qualities of historical buildings and sites, as well as the quality of interventions. Authenticity criteria are a crucial factor in accepting historical objects/sites for the UNESCO World Heritage List. The aim of the research presented in this paper was to verify the practical applicability and implementability of the “authenticity test” (characterized in the ICOMOS Document and related studies) using the existing theoretical framework as well as its adaptations. Since the research was carried out in Central Europe, the actual “test” had been set up within the framework of a culturally relevant understanding of authenticity. On its basis historic structures have been analysed and by their means also architectural units. The theoretical characteristics (Form and Design, Environment, Function, Historical structures – in materiality and used technologies, Spirit), of the test were applied to historical building structures located in the World Heritage Site of Banska Stiavnica (exceptional town rich in historical structures, technical and cultural history). In order to assess the quality of previous restoration works and the degree of intervention on historic structures – vertical and horizontal (wooden ceilings, vaults, timber structures, staircases, portals, windows and doors, etc.) had been subject of non-destructive analyses based on a method developed for this purpose. It can be used for assessing or evaluating the quality and degree of interventions on historical structures/the degree of conservation and restoration and finally for evaluating the degree of preservation of their authenticity. These research methods can be inspiring and useful for experts in practice – for assessing the needed degree of intervention in historical structures as well as for obtaining the most objective assessment of the preserved authenticity.

In this study, temporal variation of charring depth of wood studs inside wood-frame walls (WFWs) in fire was investigated. First, the time variation in the surface temperature of wood studs inside WFWs was deter-mined based on ISO 834 fire-resistance tests, and the resulting heating conditions were used in subsequent heat exposure tests. Then, wood stud specimens of four different wood species (Chinese fir, Japanese cedar, southern pine and spruce) were each subjected to a heat exposure test in an electric furnace. The results exhibited no significant correlation be-tween the charring depth of the wood stud specimens and the preheating density. In addition, the test data validated that the equation proposed by Sugahara can be used for predicting the charring depth of wood studs in-side WFWs in a fire.

Earthen masonry is a historic construction technique widespread in the river Ebro basin (Spain). These masonry walls are made of small earthen blocks, such as adobes [1]. Throughout history frequent floods of the river Ebro have threatened the integrity of earthen masonry construction. Due to climate change, this region is undergoing an increase in the severity and frequency of flood events, causing considerable losses to architectural heritage [2]. According to various studies, earth as a building material has hygroscopic characteristics which influence its resistance to water [3]. The devastating effects of flood events on historic structures due to changes in the interaction between subsoil and foundations include damage to the superstructure [4]. This research proposes a flood risk assessment methodology following a component-based modelling framework. The susceptibility to floods of the building components is evaluated, considering the material, structural and morphological characteristics [5]. The conservation state of the assets is also considered, analysing material weathering, damage, and crack patterns. The individual parameters involved in the assessment have been weighted in order to ensure significant results. The methodology has been applied to a group of municipalities located in the floodplain of the middle course of the river Ebro, and this research aims to carry out a flood risk assessment of adobe buildings on a local scale. Different risk levels have been found depending on the specific characteristics and conservation state of individual assets. The correlation between structural damage and flood effects is examined to identify the origin of damage and recurring crack patterns. Finally, mitigation strategies are discussed in relation to the importance of the conservation of architectural heritage and vernacular construction traditions.

The Sendai Framework for Disaster Risk Reduction (SFDRR) upholds the development and implementation of measures to reduce hazard exposure and vulnerability to disasters. Among other aspects, the SFDRR recognizes the importance of cultural heritage for society, thus emphasizing the need to assess the impact that potential hazards may have on the built cultural heritage. Developing adequate risk assessment and management processes are fundamental towards this end and disaster damage and loss data are known to be essential for such processes. The development of systems, models and methods to collect and handle such data is, thus, seen as a worldwide priority. In this context, the paper presents a database framework for the worldwide collection of immovable cultural heritage disaster loss data currently under development. The concepts and technical aspects related to the data being collected and its structure are discussed, as well as the type of indicators being recorded. Challenges regarding disaster loss data collection for cultural heritage are discussed, as well as the benefits of these data for developing more rational disaster risk management approaches for cultural heritage.

The impacts of climate change, such as extreme events and progressive global warming, threaten the conservation and habitability of urban cultural heritage. Understanding climate risks to heritage must be part of planning and policy decision-making processes to increase the resilience and sustainability of both social and built environmental systems.. However, despite a large body of literature on climate-related hazards, there is a notable knowledge gap regarding a holistic conceptualization of hazards in historic urban areas, especially in the case of heat waves and urban heat island phenomena.The main goal of this study was to analyze and represent the interaction between historic built environment and heat waves via Geographic Information Systems (GIS) data, considering the vulnerability of historic areas both as urban systems and as heritage areas. To frame a holistic approach, socio-economic, cultural, governance (services and resources) and physical (gathering tangible characteristics of all infrastructures, elements and buildings) aspects of the system are taken into ac-count. To this end, a multicriteria risk assessment methodology is developed. Key performance indicators, criteria and requirements addressing relevant vulnerable elements of historic urban areas are identified for the development of the methodology. Moreover, as the foundation for the risk assessment, a categorization based on vulnerability to heat waves is proposed for both buildings and urban spaces. Here, this methodology’s results and its application on a GIS-based model in the historic area of Bilbao (Basque Country, Spain) are presented. This work aims to be replicable and to serve as a reference for future holistic assessments of heatwaves risks in historic urban areas worldwide.

Frequent large-scale earthquakes, climate changes, manmade hazards, and the duration of the service are the possible origins of structural damage in Taiwan. To detect the changing features and damage states of the structures, the demand for understanding the unknown system models of the operating structures has risen. The accuracy of structural health monitoring has become a significant issue. Therefore, four kinds of refined data-driven stochastic subspace system identification (SSI-DATA) methods, namely the mode-by-mode methods, are proposed in this research. Because the mode-by-mode methods only extract a single mode per iteration, the “mode elimination” and “signal reconstruction” steps are added to the traditional SSI-DATA. The mode elimination is realized by removing the singular components that have been exploited in the identified mode. Meanwhile, the signal reconstruction employs a similar approach used in the singular spectrum analysis after the Hankel matrix is regenerated with the removal of identified modes. Moreover, the effective projection operations and modification of the singular value decomposition process are employed in the refined methods. A unified analysis procedure is also introduced to automatically extract all the concerned modes one by one using the methods, while the errors between the reference frequencies and identified frequencies and the calculated frequency resolutions are the criteria for selecting modes. To verify the proposed methods, cases of a simulated eight-story frame and the actual operating bridge structure are studied using the proposed system identification methods. Consequently, the identification results show that the refined methods can yield slightly more accurate modal parameters of the structures. Moreover, the computational time of the second, third, and fourth methods is much less than the traditional SSI-DATA.

Flooding is among the natural hazards that cause the most significant damage to immovable and movable cultural heritage assets worldwide. Simplified flood vulnerability assessment methodologies are practical tools that can support decision-making strategies to address potential flood damage in cultural heritage assets. However, existing flood vulnerability assessment approaches tailored for cultural heritage are scarce or tend to have significant limitations. Therefore, this paper proposes a new simplified framework for the flood vulnerability and risk assessment of historic buildings using a hybrid approach that combines a baseline vulnerability curve with an indicator-based method, which was defined through an in-depth literature review. The baseline vulnerability curve expresses the potential maximum damage of the historic building as a function of water depth, and accounts for flood vulnerability parameters that reflect the geometric properties of the historic building and the location of the cultural content (e.g., the height of the building, the height and location of the artwork, the existence of underground levels, the distance between the external ground level and the ground floor level). Subsequently, the vulnerability curve is adjusted using a vulnerability index, which has eighteen flood vulnerability indicators categorised into four groups, to establish the resulting vulnerability curve that provides a relative measure of the expected physical damage of the historic buildings due to floods of different intensities. The paper illustrates the methodology through an application to a historic Portuguese building exposed to floods.

A noticeable feature of the traditional timber buildings are the giant roofs with overhanging eaves and swooping edges. The roofs can lead to huge wind loads and complex load distributions on the building surface, especially on corners and edges of the roof. The wind-induced damage of those buildings always starts from the lifting up of roofing tiles. In order to understand the roof damage mechanism of traditional Chinese timber buildings and prevent them from wind hazards, this study introduces a simulation-based methodology to evaluate the vulnerability of roofing tiles under various wind directions and speed levels. Wind pressure on the roof is first obtained using CFD (Computational Fluid Dynamics) simulation. Based on Monte-Carlo method, the ‘heat map’ of failure probability of roof tiles and failure probability curves of the tile at incremental wind speed are plotted. This study is of great significance to help better understand the wind-induced damage characteristics and probabilities of the roof of the traditional Chinese timber building, and also to raise the attention to the wind risk of built heritage which is often overlooked in comparison with other hazards.

Romania is a country located in Europe, with moderate seismicity and a very large number of historical churches. Banat region is the second most important seismic area in the country, located in the western part, characterized by shallow earthquakes of crustal type. In Banat area there are many historic churches, both Orthodox and Catholic. The majority of the churches are mostly with a central nave, made in masonry, with masonry vaults and complex wooden frameworks. They also present architectural-artistic details, such as paintings made by Austrian, Serbian and Romanian painters. Many of them have suffered different types of structural damages after past earthquakes. The damage types are different, depending on the type of earthquake and on the architectural conformation. The present paper investigates the seismic vulnerability for six historic churches in Banat area and presents the results of various empirical and numerical analysis and investigations. The analysis identifies the specific vulnerable points of the historic religious structures, illustrating the seismic vulnerability of the churches with central nave in Banat seismic area. Moreover, the paper brings out the importance of investigating the seismic behavior of religious buildings, as they are permanent part of each local community, and they present an important cultural value.

Heritage buildings are often subjected to loading conditions that they were not exposed to in their earlier life span. Induced earthquakes in non-seismic regions caused by energy exploitation activities, or strains in the ground that are caused by the climate changes, are new phenomena that alter the usual loading situations for historical buildings.In this paper, monitoring results of a historical building in Groningen (Netherlands) in case of induced seismicity as well as climate change effects has been presented. Long-term monitoring results, detected cracks and relevance of the monitoring data are discussed. In the special case of Groningen, weak and agricultural soil properties dominate the structural response in the region. The gas extraction activities caused a soil subsidence in the giant Groningen Gas Field, resulting decameters of settlement in the entire area, thus an increase of the ground water level in respect to the ground surface. This is the reason why the heritage structures in the region are more vulnerable to soil-water-foundation interactions caused by climate change as compared to the time these heritage structures were constructed. The ground water monitoring as well as the interaction of soil movements with the structural response become important. The study presented here suggests ways on how to effectively monitor historical structures subjected to induced seismicity as well as harsh climate effects at the same time.It was shown here that the newly developed cracks on the structure were detected in a very narrow time window, coinciding with extreme drought and a small induced earthquake at the same time. One explanation provided here is that the soil parameters, such as shrinking of water-sensitive soil layers, in combination with small earthquakes, may cause settlements. The soil effects may superimpose with the earthquake effects eventually causing small cracks and damage. The effects of the climate change on historical buildings is rather serious, and structures on similar soil conditions around the world would need detailed monitoring of not only the structure itself but also the soil-foundation and ground water conditions.

The Geographic Information System (GIS) is increasingly used in the scientific field for the management and conservation of built heritage. The present paper proposes a GIS methodology for the collection and analysis of the data related to the seismic risk and for the management of damage prevention interventions on masonry architectural assets, based on the empirical approach. Indeed, starting from the observation of real damage, that occurred after the recent Italian earthquakes, it was possible to collect a large amount of data, which has been organized and queried using the GIS tool. This methodology was tested on two different architectural typologies, designing two different databases: protruding elements and fortified architectures. This proactive tool allowed both the correlation between constructive features and damage mechanisms, through statistical analyses, and the comparison of the damage levels with the seismic action of the site, through the introduction in the GIS of the shake-maps, to identify the empirical fragility curves, which represent the expected damage, depending on the seismic action. Then, these functions were applied to an area without earthquake damage, using the seismic actions provided by the hazard map. This methodology allowed the identification of the assets most at risk in case of future seismic events, on a large scale. Knowing the vulnerabilities of the heritage means being able to act preventively, with planned conservation strategies, optimizing the management of economic resources, and minimizing invasive interventions.

Many characteristics mark U.S. timber barns as built cultural heritage: they provide use-value and identity-value to owners and communities; they are physical records of the history of individual farms, U.S. farming communities, and technological development; they are vernacular constructions, designed and built by a wide variety of entities with a wide variety of styles and technological understandings; and they are formed of historic and even rare materials. Further, as buildings distinguished by a large innate capacity to adapt to change, they embody a case study in sustainability and resilience – a capacity which can be stewarded into the future.Although considered American icons, their status as built cultural heritage, and the resulting impacts of their loss on communities, is not well addressed. Consequently, while they receive architectural and popularized attention, their structural stewardship has not been scientifically approached. And due to their age and outdated design, these barns are particularly susceptible to natural hazards, the primary of which in this region is severe windstorms.This work covers the results to-date of a project which aims to develop a structural vulnerability assessment for historic Midwestern timber barns under windstorms, with the end goal of providing an owner-usable tool for risk assessment and remediation. The significance and broader impacts of the work include supporting sustainability and community resilience, reducing economic impacts of natural hazards and climate change, and preventing identity and cultural heritage loss in rural U.S. communities. Current outcomes include the in-situ assessment methodology developed for characterizing this specific population; results, including challenges discovered, from initial in-situ assessments; and the implications for the vulnerability assessment approach.

Climate change is one of the major challenges of the 21st century. Renewable energy systems using solar and wind do not emit carbon dioxide and other greenhouse gases and thus may contribute to stave off the worst effects of rising temperatures. Europe strives for becoming the world’s first climate-neutral continent until 2050. Therefore, also Germany intends to expand the share of renewable energy and supports the implementation of renewable energy systems. Beside all advantages, the increased installation of renewable energy solutions also has a number of disadvantages. One of those is the negative effect on the appearance of cultural heritage.In Germany, around 1.3 million cultural heritage structures exist. The German law obliges heritage protection authorities to preserve building heritage and to prevent the historical appearance of protected structures from negative effects. But, the implementation of renewable energy systems may create a conflict between environmental interests and building heritage preservation goals.The authors analyze the increased implementation of renewable energy sources in Europe in general, and in Germany in particular. They focus on solar and wind energy installations. Additionally, the authors inform about current requirements resulting from German heritage preservation law. The paper explains how renewable energy solutions may negatively affect protected historical buildings and discusses the consequences for heritage preservation. As methodology, the authors use analysis of current German court cases as well as research literature under consideration of the experience of heritage protection authorities. Conclusion is that European countries should avoid playing off environmental goals and protection cultural heritage against each other, in the interest future generations.

Active geological processes are still observed on the slopes of Gediminas Hill. These processes lead to shallow landslides which are forming in Holocene technogenic soils (t IV). The history of technogenic soils appearance and their thickness on the Gediminas Hill surface is diverse. The main Gediminas Hill soil formation and surface changes during the Gediminas Upper and Lower castle construction periods are presented in this manuscript. According to currently existing Gediminas Hill engineering geological and geotechnical conditions and data on the constructions investigations the numerical 3D finite element model was prepared. This model includes geological layers and all constructions (including also tunnels). Due to the huge number of finite elements, numerical simulations were realized in a private Vilnius Gediminas Technical University cloud. Cloud services were chosen to quickly respond to changing needs of computing resource which demands calculations capacity up to 1015 GB RAM. According to prepared numerical 3D model the possible shallow landslides areas were found. Identified areas correlate with data on the slopes displacements measurements. Numerical 3D model allows to make a prognosis of possible shallow landslides formation.

Outdoor Built Environment (BE), such as squares, are paramount scenarios in historic cities. They attract many users that can be affected by both Slow and Sudden onset disasters, depending on the combination of possible hazards, BE modification in view of the BE morphological and constructive features, and the users’ vulnerability and exposure. The coupling of sudden and slow-onset disasters represents a critical but not remote situation. This work hence provides an approach to assess coupled multi-risk in historical outdoor BE by using behavioural simulation methods and to evaluate the effectiveness of mitigation strategies. The simulation model is based on a probabilistic, multi-agent and cellular automata approach, developed in a slow-to-sudden events perspective. Heatwaves (as a slow onset disaster) affect the initial users’ position in the outdoor BE in view of outdoor temperature. Then, a terrorist act (as a sudden onset disaster) appears, thus making users evacuate from the outdoor BE. The application involves relevant typological conditions of outdoor BE to trace rapid and generalisable overviews of emergency impacts that can be then verified in specific case-studies. The slow-to-sudden events approach is applied to different BE typologies characterized by different climate conditions for hazards, terrorist attacks, and mitigation strategies. Simulation analysis mainly concerns evacuation to focus on quick events faced by users. Results demonstrate the approach capabilities in comparing coupled multi-risks conditions depending on BE configurations. The approach can outline quick solutions in the considered typological BE, and can be applied to real-world scenarios to “tailor” strategies on effective BE conditions.

When floods occur, pedestrians may be forced to evacuate the risk areas, and the presence of emergency plans is fundamental to reduce fatalities. Historic Urban Built Environments (HUBEs) in flood-prone territories are critical scenarios because of complex and compact layouts, poor implementation of risk-mitigation strategies, and attractiveness for tourists unfamiliar with the spaces. This work provides a novel risk-based methodology to determine the optimal evacuation solution by varying the approach for the path choice, and the number of available shelters in the HUBE. First, an Integer Linear Program is defined to consider different pedestrians’ approaches to the path choice (i.e.: minimizing the path length, time, effort). Then, to select the best overall evacuation solution, a synthetic Risk Index RI is developed based on Key Performance Indicators that jointly consider aspects concerning the urban layout, the event intensity, and the human motion. The application scenario is a typological HUBE with narrow streets perpendicular to each other and a square close to a river, and the pedestrians’ motion conditions depend on the hydrodynamic conditions generated by a real-world flood within the HUBE. Results identify the minimum number of shelters to guarantee the minimum RI, the optimal shelter positions depending on the path choice approach, and the best evacuation paths from each position of the HUBE. Results offer first insights on where/how to install wayfinding systems and urban furniture and could represent a first step toward the development of tools for the communication of real-time risk update.

“Twentieth-century building materials and construction techniques may often differ from traditional materials and methods of the past. There is a need to research and develop specific repair methods appropriate to unique types of construction.”Approaches for the Conservation of Twentieth-Century Architectural Heritage, Madrid Document 2011, ICOMOS.Natural deterioration caused by the ageing of the materials and their exposure to severe environmental conditions leads to a significant increase in the vulnerability of constructions. The conservation of reinforced concrete structures of the early 20th century brings challenges due to the specific characteristics of their construction processes. If at the structural level these processes are already somehow identified and linked to the systems of construction engineers such as Hennebique, Coignet, etc., at the level of decorative elements like ornaments, sculptures or others, their conservation deals with unknown techniques and requires greater care to maintain their authenticity and integrity.Reinforced concrete, which is made of cement and steel, forms a material with a reduced lifespan when compared to natural and traditional construction materials such as stone or timber. Among other sources, the degradation of reinforced concrete is often caused by the corrosion of embedded steel, responsible for important losses of material which become particularly critical in sculptural elements.When facing the need to make conservation interventions to preserve, rehabilitate, or restore degraded cultural heritage elements, several restrictions must be dealt with. Such restrictions are related to the safeguarding of the heritage’s cultural value and significance that must be weighed against safety and durability needs, as well as against the duration and budget constraints of the intervention. To assist the decision-making process about the type of interventions that can be carried out, an adequate balance of the several constraints must be sought. Therefore, in this paper, a two-step approach that can be integrated within the maintenance plan is proposed. The first step consists of a method to determine a case-by-case intervention index that gauges the referred criteria influencing the type of intervention. The referred index weighs the influence of several qualitative and quantitative criteria which are graded according to the characteristics of the cultural heritage element under analysis. The second step focuses on the development of maintenance indicators that can be used to assess the performance of the interventions that are carried out. This procedure was developed and implemented in the decision-making process related to the conservation of the decorative elements of a 20th-century building theatre in Portugal. A detailed analysis of the selected criteria for the intervention index and maintenance indicators is presented, as well as the advantages that might come from implementing the proposed procedure for the development of a sustainable conservation plan. A preliminary assessment of the maintenance indicators confirms that preventive measures decrease the number of repairs that are needed over time, meaning that the intervention index is correctly assessing the level of intervention required for a given decorative or sculptural element.

In March 2020, the capital of Croatia was hit by two earthquakes of moderate magnitudes. The earthquakes caused high economic losses, due to damage that occurred in the city centre. The city centre is mostly made up of historical masonry structures that have proven to be extremely vulnerable in the case of an earthquake. The paper represents two approaches to estimating vulnerability: an empirical and an analytical approach, respectively.The case studies building aggregates are in the city centre, Lower Town. The application of the empirical approach requires data about previous earthquakes and the damage that occurred. Firstly, the macroseismic approach, which is an index-based method, is being used. Structures were categorized into typological classes. The results were calibrated according to data from the earthquake that occurred in 2020 and are presented in terms of vulnerability and fragility curves as well. Next, the analytical approach was considered, by performing a non-linear static analysis on the selected structural unit as a representative of the predominant structural typology present in the study area. The selected structural unit was modelled in software 3Muri, using the macro-element approach. The impact of structural interaction was considered by adopting a simplified numerical procedure. Moreover, fragility curves were derived from pushover curves.The main aim of the research was to compare the empirical and analytical approaches to validate the empirical approach. While the analytical approach is more precise, due to more input information, the macroseismic method is simpler to use and it provides results on a wider scale which is useful when developing risk mitigation strategies.

The September 2017 Puebla, Mexico earthquakes caused unprecedented devastation, loss of lives and widespread damage of historical churches in Puebla, Morelos and Oaxaca. Chavez et. al. (2021) and Pena et. al. (2021) present an analysis of observed earthquake damage data, including images, which was collected within three months of the earthquake event. The analysis focuses on the type of damage to each building element (e.g. Facades and bell towers, roofing systems - vaults and domes, side walls,), and the intensity of damage (minor, moderate, severe). A database was built to manage the collected data and present it to users based on built-in queries. Access to this database has been provided to the authors of this paper.The collected data and the analysis provided in those papers form the basis for a machine learning model to automatically identify types of damage and their intensity in similar earthquake events. The machine learning model will follow the development steps outlined in Rihal and Assal (2022) and will generalize some of the data elements, such as the building type, construction method, and material. It will also consider data about the earthquake event, such as the intensity and the epicenter and data about the location of each structure and its distance from the epicenter. The model will be trained and tested on the provided data. It can also be retrained with data from other events as they become available.

This paper addresses the seismic vulnerability assessment of churches in Central Italy and discusses the main outcomes of the in-situ survey activities carried out within the cooperation agreement between the Italian Network of University Laboratories of Seismic and Structural Engineering (ReLuis) and the Ministry of Cultural Heritage (MIC), aimed at collecting structural and damage information of existing churches. The seismic vulnerability assessment is performed on the basis of an empirical methodology applied through the use of the MaCHRO evaluation form. A predictive model, already calibrated for churches of the inner Abruzzi, is here extended to the Central area of Italy where, due to the high seismicity, cultural heritage features major alterations occurred over time. In the first part of the paper, the analyzed sample of churches is presented. A wide description of the anti-seismic devices and fragility indicators recurrent in the ancient masonry buildings of the territory is provided, highlighting their fundamental role in preventing (or promoting) specific local failure mechanisms. Statistics regarding all information of interest from a seismic viewpoint are given for the entire sample. In the second part of the work, the vulnerability of each church is assessed in terms of vulnerability indices (IVs), evaluated according to the procedure given by Italian Guidelines of Cultural Heritage. These indices account for both the sources of fragility and the existence of possible protection devices for each macro-element. Finally, based on the obtained IVs, fragility curves for predicting the extent of probable earthquake-induced damage in the analyzed churches are estimated. The results are proven to be useful for seismic risk mitigation purposes, allowing to define priorities of intervention on a large scale.

Impact tests on full-scale masonry panels are undertaken in order to explore the vulnerability of vernacular construction to rockfall hazards in mountainous areas. Seven 2.5 m high walls made of bricks subjected to a static gravity overload are subjected to a dynamic impact load on their centre, provided by ETAG concrete blocks launched at different energies (from 5 to 15 kJ). This experimental campaign is analysed through numerical simulations. Two different approaches have been explored: a micro-modelling based on the discrete element method (DEM) using the free software Siconos from Inria and a macro-modelling based on the finite element method (FEM) using Abaqus. Models have been adapted to the specificity of masonry structures under dynamic stress by hard shock. They show the strong influence of the overload on the resistance of the wall. The present work aims at assessing the damage generated by an impact on a masonry structure in real conditions. It also leads to question the failure characterisation of the structure after impact. On a long-term perspective, this work is intended to provide damage curves for masonry buildings and thus contribute to the development of normative prescriptions for natural hazard prevention.

Masonry bell towers represent some of the most iconic historical assets of European heritage. However, the typical poor mechanical characteristics of masonry, lack of maintenance and conservation interventions as well as their high slenderness could lead to significant vulnerability against natural actions, such as earthquakes. Given their widespread diffusion in the European and, especially, Italian territories, the seismic vulnerability assessment of such buildings at territorial level can benefit from simplified large-scale methods based on a low amount of input data. Such methodologies, combined with hazard and exposure quantification, are thus adopted for simplified risk analyses leading to the definition of prioritisation rankings aimed at planning intervention activities.In this paper, a novel methodology for fast seismic vulnerability assessment developed by the authors is described. This is formulated as a simplification based on parameter reduction of an existing analytical approach providing a force-based estimation of the structural capacity under horizontal loading. The capacity is then turned into a suitable vulnerability index ranging from zero to one. The methodology is applied to a sample of about 25 bell towers of Naples to perform a preliminary seismic risk analysis by means of purposedly developed fragility curves.