Environmental Challenges in Civil Engineering III

The documented damage due to earthquakes has shown that a seismic structural design is insufficient to have good safety conditions if the soil filter effect and the Soil-Structure Interaction (SSI) are not considered. An important modification of the seismic action evaluated according to the technical regulations can occur because of site effects. The dynamic response at the foundation level often differs remarkably from the free-field one because of the kinematic and inertial interaction. Mitigating the seismic risk represents a huge environmental challenge in medium-high seismic hazard areas. The paper proposes a manageable procedure for estimating at a large-scale the SSI effects on the seismic actions impacting ancient masonry churches present in some municipalities in the Etna volcano area (Catania, Italy). The investigated churches represent a valuable cultural heritage in Italy, the preservation of which is a serious environmental and social challenge. By identifying the churches at the highest seismic risk, it was possible to define the priority in implementing seismic improvement interventions, thus ensuring the conservation of the historical heritage and the safety of local communities. Local Site Response (LSR) analyses were performed in free-field conditions; then the Author analyzed the fundamental periods and the pertinent spectral accelerations of the investigated churches, considering both the flexible-base building configuration and the fixed-base one: S_a(T_SSI) and S_a(T_fixed). Their ratios were assumed as indexes of SSI effects. The procedure discussed here can easily be extended to other villages or cities.

The economic and social damage caused by earthquakes is often tremendous, especially in historical sites where the buildings often have inadequate earthquake-resistant seismic structures. The damage caused by past and recent earthquakes demonstrates the necessity to promote specific actions for renovating historic buildings, highlighting the decisive role of the soil filter effect and dynamic soil-structure (DSSI) interaction. The eastern part of the Sicilian area (Italy) is characterized by high seismic hazard, and it is rich in historical churches with a great cultural heritage value. In this context, a great challenge is to evaluate their seismic risk and establish which of them are affected mainly by DSSI effects. This paper deals with a set of investigations for large-scale estimation of DSSI effects for historical churches of the eastern Sicilian area with the goal of establishing a priority for planning the seismic retrofitting tasks, suggesting more detailed analyses of DSSI phenomena. The analyses are performed on different historical churches, varying the properties of the masonry. Specifically, the effects of the number of seismic motions and the seismic behavior of the soil on the spectral accelerations are investigated, considering a fixed-base configuration and a flexible-base configuration that takes into account DSSI.

Buildings are designed for a 50-year lifetime. However, they can stand out for more without major repairs, depending on materials quality, climate aggression, use, and maintenance, among other aspects. Considering that Algarve’s building boom occurred between the 60s and 80s, a significant quantity of buildings is achieving their lifetime. Consequently, the demand for rehabilitation is rapidly increasing. Buildings, like other infrastructures, deteriorate over time due to several factors. However, the lack of maintenance stands out, and a structural survey is essential to determine the load capacity and ensure the safety of the society. Corrosion of reinforcement and spalling of the concrete cover may lead to loss of strength and unserviceability. Corrosion is initiated mainly by chloride contamination or exposure to atmospheric CO₂, and the presence of moisture accelerates this degradation processes. In this study, different types of buildings located along the Algarve coastline, suffering from serious structural pathologies resulting mainly from the carbonation of the concrete, are presented. This article describes the constructive pathologies observed and presents the campaign test results, including carbonation tests, the presence of chlorides, corrosion potential, and measurements of covers, among others. These real examples show a rather deteriorated state of the building constructions, which are more than 50 years old in this touristic region. Thus, a priority line on the path towards housing sustainability is urgent. The authors pretend to launch an SOS signal and a call for action, to implement maintenance and rehabilitation plans legally.

The paper deals with diagnostics and calculating the load-carrying capacity of the prestressed concrete railway bridge near the town of Stará Ľubovňa, the northeast part of Slovakia. The bridge object was probably built between 1965 and 1966 because the original project documentation was drawn up in 1964. The bridge is located on the Orlov-Podolínec railway line at 21.3 km. The bridge is made from precast prestressed post-tensioned box girders of three single spans. In the ground plan view, the bridge object is curved. In the transverse direction, the box-girder consists of two longitudinally connected parts connected in the transverse direction using transverse prestressing. The overall cross-section is a box-girder with 3 openings and 4 vertical walls. In 2023, in cooperation with practice, the Department of Structures and Bridges, the Faculty of Civil Engineering, University of Žilina, was asked to carry out the technical survey and diagnosis of the mentioned bridge. Visual inspection, diagnosis, and verifying real dimensions and material characteristics were requested. Non-destructive and semi-destructive testing methods were used to determine the material properties of concrete, reinforcement, and prestressing steel. After that, the load-carrying capacity calculation was done. For this purpose, a numerical 3D FEM model was created. The standard approach was used to determine the load-carrying capacity according to provisions, which consider the modified (lower) reliability levels and their adequate partial safety factors according to Eurocodes. The results of the diagnosis and the calculation are presented in the paper.

The paper presents some issues concerning the renovation of the Kyiv TV tower after the missile fire that followed the attack on Ukraine by the Muscovite invaders. It is noted that the 385-m-high Kyiv TV tower was inaugurated on July 30, 1973, and at the time of construction as well as for the next 37 years, it was the highest freestanding welded steel lattice tower in the world, and many new solutions were applied during the design of the tower. It is noted that on March 1, 2022, the Muscovite invaders launched a targeted double missile attack on the TV tower, which, despite some damage, withstood the impact of the blast wave. It is noted that after the attack on the TV tower, an inspection of its technical condition was carried out, which indicated that the joint of the tower metal structures at elevation + 56,000 m, which was directly in the center of the explosion, suffered the most damage. In some other metal structures, only separate holes, cracks, and dents of various sizes were found, which were formed due to the impact of the missile fragments. Design features for new TV tower structures intended to replace the destroyed elements and strengthen partially damaged elements are defined based only on solutions that would not interrupt the existing structural layout and stress state of the tower.

In global warming conditions during the last sixty years, climate changes towards warming and mitigation have been observed in the territory of Europe and Ukraine in particular. Such changes can lead to a change in the atmospheric precipitation pattern and extreme weather events – very heavy rains, snowfalls, squalls, dust storms, and blizzards, the amount of which has increased significantly over the past decade around the world. The consequence of changing precipitation patterns is the change in climatic loads on building structures – snow, wind, ice, and wind loads under icing conditions. Because the pace of global warming in Ukraine is generally faster than in the world, specifying climate loads is an important step to prevent possible damage due to natural meteorological events, which is the most dangerous demonstration of climate instability. This paper is the summary of research carried out in 2021, devoted to evaluation of the change trends in climatic loads and the subsequent conclusion regarding the need to clarify the zoning maps, which should be applied during the norm setting of loads, for which a comparison of climatic characteristics for the main meteorological processes is carried out. It is proposed to amend the load values for snow and wind, which were set in the state building codes DBN V.1.2-2006 “Loads and influences. Design norms” and National Annex`s to EN 1991.

A major mistake in repair and reconstruction projects is to treat the analyzed elements as homogeneous and subject to one-dimensional impacts. For the analyzed case, there is a need for a different analysis depending on the elements’s location. Each isolated case requires a different approach to other technologies and a different repair methodology to achieve the necessary durability. A deeper analysis of the past state, historical changes, the current state, and the expected durability makes it possible to determine additional conditions for future operation, giving the possibility of long-term durability and use of the entire facility. The analytical and research approach to determining the phenomena occurring in the designed, operated, repaired, and rebuilt facilities must be broad to set all the factors determining decisions on the design, construction, repair, reconstruction, and reconstruction of facilities. The traditional treatment of facilities without a detailed analysis of place and time is unjustified. Illustratively, unjustified in most cases is the typical: “There is a hole; it needs to be plugged”. We holistically determine what the hole is, where it came from, what effect it had on the neighborhood, what effects it had if left, what and how to fix it, and what long-term effects the repair will have on the hole and its surroundings. When examining and analyzing the elements, it is important to remember that the whole is most important. A holistic view, bringing together holistic and individual impacts, makes it easier to see the non-obvious effects caused by them.

Future-oriented flow production depends on consistent digitally controlled tool systems in the digital replica network. Concrete spray extrusion, for example, can be used to create facade modules consisting of a thin layer of shotcrete and rib-shaped supporting structures with high strength and excellent surface qualities. The newly developed combined nozzle offers the ability to both spray and extrude, adapting to mortar and concrete. Furthermore, flow production includes the automated integration of anchors for attaching facade modules to buildings, for which special anchor and tool systems have been developed. The measured values from the tests demonstrate the feasibility and increase in productivity. The creation of a digital replica (Industry 4.0) was based on the generated data and parameters. The resultant increase in productivity has positive economic effects. The use of lightweight structures enables the series implementation of modular constructions.

Lightweight structures, especially sandwiches made from resource-efficient, ecological, and sustainable construction methods in automated manufacturing processes, are important topics for the future. This paper reports on the development of a sandwich construction method based on the use of clay as a face material, natural fiber-based reinforcement systems, and corrugated cardboard elements as shear-resistant cores using robot-assisted manufacturing. The free moldability of the clay and the freedom of design in producing the corrugated cardboard elements allow for both flat and curved sandwich elements. The use of natural fiber-based reinforcement systems also allows the thickness of the clay surface layers to be adapted and reduced, which contributes significantly to mass reduction and offers the possibility of increasing the proportion of thermal insulation materials. The compartmentalized structure of the core can be specifically used to integrate acoustic or thermal insulation materials. Bio-based materials such as cellulose flocks, jute, hemp, or flax are particularly suitable. Functional integration has been successfully expanded to include surface heating and the integration of light and touch sensors for light control.

The paper presents the sustainable production of flexible and recyclable formwork elements. The models are produced by means of extrusion and processing concrete in a fresh and hardened state. The model milled to target dimensions enables resource-efficient molding with various casting resins. The combination with conventional formwork elements enables the production and simple demolding of complex concrete elements without demolding drafts or with local undercuts. A clinker-reduced concrete mixture with a lower CO₂ footprint than conventional concrete mixtures for 3D printing has been developed as part of the research. The extrusion and machining programs are created using Grasshopper, a visual programming environment used as an extension to Rhinoceros CAD software to create parametric geometries. This enables programming for planning the paths and controlling the 6-axis industrial KUKA robots. The extruded and processed formwork elements can be recycled. The material can be fed back into the printing process without negatively affecting the rheological and mechanical parameters of the concrete. The resulting material cycle is the key to the efficient and sustainable production of precast concrete products.

The paper presents the development of a resource-efficient automation solution for the production of prefabricated staircases using additive-manufactured, component-integrated formwork systems. The component-integrated staircase formwork is produced in an automated process by concrete extrusion with a special 3D printing concrete, then reinforced with steel and filled with casting concrete. In addition to the development and implementation of the component-integrated formwork concept and the associated automated production process, the development of a parametric staircase model is presented, which significantly advances digitalization in the manufacturing of precast stairs. The model considerably simplifies the creation of CAD geometries and the generation of production programs, enables the visualization of the production process, and provides a process simulation to evaluate the feasibility of production-critical designs. Particularly in light of the increasing shortage of skilled workers, the new manufacturing strategy, in conjunction with strong digitalization, offers the opportunity to relieve the burden on skilled workers, increase productivity, and make an important contribution to increasing efficiency and cost-effectiveness in production. The paper provides an overview of the entire development process from the conception phase to the final realization of the precast staircase. The focus is on material development and characterization, the development of a parametric staircase model for generating the production programs, the manufacturing and investigation of large-scale test specimens to verify the production strategies, and the production-related implementation of the component-integrated staircase formwork including reinforcement and casting process.

The current research work aims to utilize materials as inert or pozzolanic additives to produce precast concrete elements in the extrusion process (3D concrete printing). This material is a residue with a mineral-silicate composition that has been processed using pneumatic flotation. It is a by-product of the extraction of valuable metals from dumps. For this purpose, the material has been comprehensively characterized mineralogically, chemically, and physically before processing. The present studies aim to determine requirements and restrictions for the appropriate preparation of the material. This material is intended as an additive for the partial substitution of cement in concrete mixtures without affecting the existing properties. The newly developed concrete mixtures were thoroughly examined as part of a material technology study. Limit states were determined in relation to the maximum dosage of the filler for existing concrete mixtures. As a result, the mechanical and physical properties were analyzed to ensure consistent strength requirements. The influence of the filling material on the time-dependent drying behavior and the strength development were examined in detail. By using the new concrete mixture in the extrusion process, its strengths in terms of sustainability are expanded. The innovative potential of the extrusion process in the construction industry offers significant opportunities for realizing more sustainable building structures. This is especially evident in the context of the production of precast concrete parts, where sustainability and the substitution of cement play a central role. The possibilities include improved material efficiency, increased design flexibility, and reduced environmental impact.

This study aims to analyze the behavior of precast concrete slabs under both short-term and long-term loading conditions. The investigation focused on two commonly used precast slabs in building construction: the Vector (half-slab) and Teriva (beam-and-hollow tile floor). The experimental program involves full-scale slabs to non-uniform loading to investigate crack morphology, lateral interaction between precast elements, and displacement characteristics. Computational analyses were also conducted using various models, including beam, grid, and slab models. The calculated displacements in the beam model significantly overestimate the observed displacement values. These differences indicate the complexity of accurately predicting the behavior of precast slabs. The study highlights the significance of considering two-way action in the expert assessment of precast slabs.

Outdoor tourism represents a form of vacation immersed in nature, characterized by a pronounced seasonality linked to the summer season. In recent years, the sector has experienced significant growth due to introducing a hybrid housing system known as the maxi-caravan, produced industrially. This housing unit is considered an ideal solution due to its removable nature, portability, and comfort. The growing ecological awareness and the expanding market for this product require an enhancement of interior spaces to make the mobile unit more efficient in terms of environmental and spatial comfort and flexibility. This article proposes a maxi-caravan project designed for year-round use, characterized by innovative experimentation for interior spaces. Beginning with a study on ergonomic principles, the research explores the debate on rationalist and metabolist minimal living. The study identifies a multifunctional internal organization through versatile spaces. Regarding the mobile unit's sustainability, an off-grid plant systems are proposed. The project’s envelope, combined with the technical systems, allows the maxi-caravan to be used year-round. The sustainability of the maxi-caravan extends beyond materials, assembly, maintenance, and disposal, aiming to become resource-independent. Furthermore, the project aims to reconcile the paradigm of outdoor living with a high level of comfort, creating internal environments that surpass traditional camper and trailer standards. The research distinguishes itself by developing a specific methodology for studying minimal spaces within the maxi-caravan. The research combines literature reviews with empirical approaches, providing methods applicable to a comfortable and off-grid mobile unit resulting from collaboration between researchers and industrial producers.

Since 2023, the Department of Civil Engineering and Architecture at the University of Pavia has secured funding as a Department of Excellence in Italy with the DORIAN project. The project aims to create the Digital Twin of the city of Pavia, Italy, to develop a safe, sustainable, and resilient city. Within the project, the AUDe (Architecture and Urban Design) laboratory at the University of Pavia, within the Department of Civil Engineering and Architecture, aims to integrate the project with developing design ideas for Pavia to mitigate climate change. The research is based on two workshops organized by the AUDe laboratory in 2021 and 2022 titled “Towards an ecological city: Water & Public Space” and “Towards an ecological city: Water & Public Space_Design along Naviglio Pavese” as well as a doctoral thesis titled “Public Space Water Space. Designing collective space with water: adaptive strategies for the ecological city.” The addressed theme is the development of ecological cities through the design of public spaces with water to mitigate the effects of climate change in Pavia and enhance water resources. Analyzed topics include climate change and its effects on urban contexts, which can be mitigated by adopting nature-based solutions. Public space is the most suitable space identified for adopting such strategies, precisely due to its flexible nature and as a place where working with the soil is possible. During the Summer Schools, students were tasked with developing architectural projects for public spaces in Pavia using water as a resource. The aim was to introduce environmental mitigation systems, already extensively studied in metropolitan contexts, to a medium-sized city like Pavia, characterized by a strong historical character and a consolidated urban and architectural structure. The paper explores the research themes addressed and analyzes the projects realized by students during the workshop as the outcome of a design process that begins with a strong theoretical foundation at the drawing stage, serving as the starting point for developing the DORIAN project.

The universal design of the urban environment and architectural accessibility of public space are important issues in an era of growing awareness of the needs of people with disabilities. The article reviews recent literature on the topic to identify research gaps and create future research agendas. A semi-structured literature review was performed using specific keywords, narrowing down the results to articles in fields such as architecture and urban planning. The analysis provided insight into commonly used methodologies and highlighted important concepts and problems, including the need for public spaces to meet the needs of a diverse group of citizens and the limitations of traditional models for measuring accessibility. Further research is necessary to address gaps in knowledge, such as analyzing the overall structure of urban spaces rather than individual elements, towns and villages as a subject of the study and participatory research involving people with disabilities.

The author cites her research into buildings built from the 1970s to the present day, comparing the spatial relationship between greenery and architecture, the functional relationship with technical solutions, and the symbolic and associative relationship. The 1990s saw some spectacular realizations of nature-integrated architecture: Bad Blumau by Friedensreich Hundertwasser, Fukuoka Prefectural International Hall by Emilio Ambasz, and, on Polish ground at the same time, the Supreme Court building in Warsaw and the Warsaw University Library designed by Marek Budzyński. Later projects are more mature, using technical innovations and realizing the idea of sustainable development through integration with greenery. The article is the result of an analysis of selected projects by architect and urban planner Marek Budzyński—a pioneer of ecological and landscape architecture in Poland who gradually introduced individual ideas and successive innovative solutions into his projects until the standards of today’s large cities, where designing in the spirit of sustainable development has become a necessity. Through an analysis of the integration of architecture with greenery, urban and housing estate assumptions, and public buildings, the author shows how the ideas of sustainable development evolved in practice in Poland.

This research explores the challenges and sustainability issues in refugee camps worldwide, examining their urban nature and the gap between planning and reality. Using examples like Moria, Calais Jungle, Shu’fat, Sharawi, Dadaab, and Zaatari, the study argues that refugee camps should be viewed as urban settlements, even temporarily. Given the debate on the urban nature of the refugee camp, as illustrated by Herz and Agier and other illustrious theorists, if the camp is to be considered a city, it is correct to approach the planning of the camp with urban theories. The paper proposes a sustainable architectural approach rooted in appropriate technology, vernacular knowledge, and participatory construction, emphasizing efficiency and resilience and fostering a sense of identity among residents. The study examines the challenges of waste and water management and argues for a multi-faceted approach that involves camp residents in decision-making and infrastructure maintenance. It highlights the importance of addressing water, sanitation, and hygiene challenges to ensure health and minimize environmental impact. In conclusion, the research calls for urgent sustainable improvements in refugee camps, emphasizing a holistic approach considering architectural sustainability, resource management, and community involvement. It underscores the need for specific disciplinary approaches tailored to humanitarian emergency contexts while acknowledging areas for further research.