Skip to main content
main-content
Top

About this book

This book includes a collection of chapters that were presented at the International Conference on Earthquake Engineering and Structural Dynamics (ICESD), held in Reykjavik, Iceland between 12-14 June 2017. The contributions address a wide spectrum of subjects related to wind engineering, earthquake engineering, and structural dynamics. Dynamic behavior of ultra long span bridges that are discussed in this volume represent one of the most challenging and ambitious contemporary engineering projects. Concepts, principles, and applications of earthquake engineering are presented in chapters addressing various aspects such as ground motion modelling, hazard analysis, structural analysis and identification, design and detailing of structures, risk due to non-structural components, and risk communication and mitigation. The presented chapters represent the state-of-the-art in these fields as well as the most recent developments.

Table of Contents

Frontmatter

Chapter 1. The Ranges of Uncertainty Among the Use of NGA-West1 and NGA-West 2 Ground Motion Prediction Equations

In this study, a comparison of the use of NGA-West1 and NGA-West2 ground motion prediction equations (GMPEs) to estimate peak ground acceleration (PGA) and spectral acceleration (SA) at 1.0 s for moderate to high seismic hazard area have been presented. This paper focuses on updated estimated ground motion due to the use of NGA-West2, and their impact on the hazard map related to those estimated by NGA-West1 for two cities in South East Asia with different level of seismic hazard. In addition, comparison of the range of epistemic uncertainty between NGA-West1 and NGA-West2 have also been determined. In general, the combined effects of lower medians and increased standard deviations in the new GMPEs have caused only small changes, within 5–20%, in the probabilistic ground motions for considered sites compared to the previous results. In addition, the results illustrate that the variation in seismic hazard due to GMPEs seems to be lower for NGA-West2 comparing to NGA-West1 for area with controlling earthquake magnitude of 6.0–6.5. However, for area with controlling earthquakes of small magnitudes in the range 5.5–6.0 or very strong earthquakes (M > 7.5), the variations in seismic hazard seems to be similar for both NGA-West1 and NGA-West2.

Teraphan Ornthammarath, Pennung Warnitchai

Chapter 2. On the Manifestation of Ground Motion Model Differences on Seismic Hazard Sensitivity in North Iceland

In this study, probabilistic seismic hazard assessment (PSHA) for North Iceland is explored in terms of its sensitivity to one of its key elements, the selected ground-motion models (GMMs). The GMMs in previous PSHA studies for Iceland are reviewed and in some cases recalibrated to the Icelandic dataset using a Markov Chain Monte Carlo (MCMC) algorithm which is useful in regions where the earthquake records are scarce. To show the ground motion model variability as it is manifested in PSHA uncertainties, the hazard maps of standard deviation and coefficient of variation (CV) of PGA at two hazard levels for GMMs before and after recalibrating are shown. The results indicate that the recalibrated models are promising candidates to be applied for future hazard studies in Iceland, but more importantly they show how to what extent and how the epistemic uncertainty of the GMMs contribute to patches of heightened hazard uncertainties, especially at near- and far-fault distances where there is a particular lack of data.

Milad Kowsari, Benedikt Halldorsson, Jónas Thor Snæbjörnsson

Chapter 3. Bayesian Hierarchical Model of Peak Ground Acceleration for the Icelandic Strong-Motion Arrays

A reliable estimation of regional ground motion plays a critical role in probabilistic seismic hazard analysis (PSHA). The earthquake resistant design of structures within a region of a small spatial scale is often based on the assumption of relatively uniform form-factors which leads to the assumption of same station condition. However, for some small-scale regions this may not be the case. In this study, we propose a new Bayesian Hierarchical Model (BHM) for peak ground acceleration (PGA) records from two small-aperture Icelandic strong-motion arrays. The proposed BHM characterizes source effect, local station effect, source-station effect, and an error term that represents the measurement error and other unaccounted factors, separately. Posterior inference is based on a Markov chain Monte Carlo algorithm that uses the Metropolis algorithm. Uncertainty in unknown parameters is assessed through their joint posterior density. Analysis of PGA records based on the proposed BHM will improve the comprehensive understanding of the source effects, localized station conditions, and wave propagation.

Sahar Rahpeyma, Benedikt Halldorsson, Birgir Hrafnkelsson

Chapter 4. Towards an Automated Kappa Measurement Procedure

We present an automatic algorithm for measuring the high-frequency acceleration spectral decay parameter (κ) on seismic records of strong ground motion. This task is often done manually due to the strongly varying quality and characteristics of earthquake recordings, such that an adaptive algorithm is required to mostly reproduce manual measurements but in a less subjective way. We prepended a P- and S-phase picking algorithm to achieve complete automation, and we discuss the common pitfalls for such attempts regarding both algorithms. To test the measurement schemes, a dataset of accelerograms from South Icelandic earthquakes is used on which all parameters have been determined manually as well. The proposed program facilitates automatic creation of κ-value databases from input record databases, which might be used in regional hazard analyses and to better constrain earthquake source parameter inversions.

Tim Sonnemann, Benedikt Halldorsson

Chapter 5. Application of MASW in the South Iceland Seismic Zone

Multichannel Analysis of Surface Waves (MASW) is a seismic exploration method to evaluate shear wave velocity profiles of near-surface materials. MASW was applied at seven locations in or close to the South Iceland Seismic Zone, providing shear wave velocity profiles for the top-most 15–25 m. The profiles were utilized for seismic soil classification according to Eurocode 8. The results indicated that the sites that are characterized by sandy glaciofluvial, littoral or alluvial sediments fall into category C and the sites where the deposits are cemented to some degree belong to category B. Furthermore, the MASW measurements were used to evaluate the liquefaction potential at a site where liquefaction sand boils were observed during an Mw6.3 earthquake occurring in May 2008. The simplified procedure of assessing cyclic stress ratio to normalized shear wave velocity revealed that liquefaction had occurred down to 3–4 m depth, which is consistent with observations on site.

Elín Ásta Ólafsdóttir, Bjarni Bessason, Sigurður Erlingsson

Chapter 6. Experimental Study of All-Steel Buckling-Restrained Braces Under Cyclic Loading

Buckling-restrained braces (BRBs) are the type of braces which capable of yielding in tension and compression under cyclic loading. BRBs provide the nearly symmetrical hysteretic response under cyclic loading and higher energy dissipation. Though the all-steel BRBs are considered as cost-effective and light-weight, the main parameters influence their cyclic performance are the flexibility of steel restraining elements, friction between core the restrainers, and interlocking mechanism. In this study, the cyclic performance of all-steel BRBs (ABRB) with angle restrainers has been investigated experimentally. Two reduced-scale ABRB specimens with and without welded stiffeners are tested under cyclic displacements in accordance with AISC 341-10 (2010) provisions Both specimens are subjected to axial strain of 3.5%. The main parameters studied are hysteretic response, energy dissipation response, and displacement ductility. A finite element model has also been developed to predict the cyclic response of ABRB specimens and to compare the experimental results.

Ahmad Fayeq Ghowsi, Dipti Ranjan Sahoo

Chapter 7. Seismic Design Procedure for Staggered Steel Plate Shear Wall

Steel plate shear wall (SPSW) is used as a lateral force-resisting system capable of dissipating the input seismic energy through metallic hysteresis. High axial force demand on the vertical boundary elements (VBEs) results in relatively heavier sections at the lower story levels of SPSWs. This lead to a non-uniform interstory drift distribution over the height, which may exceed the acceptable drift limits. Staggering of web plates can reduce the axial force demands in VBEs, ensuring better drift distribution and improved energy dissipation. This study aims at developing a design methodology for the staggered SPSW systems having the similar over-strength as the conventional counterpart to ensure an acceptable yield mechanism. A linear static analysis procedure is used to predict the axial and flexural demand in VBEs. The effectiveness of the proposed procedure is validated through the non-linear analysis for a six-story SPSW.

Abhishek Verma, Dipti Ranjan Sahoo

Chapter 8. Passive-Hybrid System of Base-Isolated Bridge with Tuned Mass Absorbers

Nowadays, improved versions of earthquake response modification devices are being introduced to maximise efficacy in dynamic vibration abatement in structures. Here, hybrid system has been proposed to be used for earthquake response modification of bridges by combined use of two passive devices: base isolation systems and tuned mass absorbers. The efficacy of the passive-hybrid system is verified by implementing it in a reinforced concrete (RC) bridge subjected to earthquake ground motions. The RC bridge has three continuous spans and supported on two piers in the middle and abutments at the ends. In the developed numerical model, the flexibility of the founding soil has been accounted for. The numerical model is analysed to determine the dynamic response of the bridge equipped with the passive-hybrid system and a comparison is made with the dynamic response determined without installing such systems. Primarily, it is concluded that the passive-hybrid system exhibits significantly improved performance in dynamic response abatement of the bridge. Nonetheless, the founding soil flexibility at the bottom end of the piers influences the efficacy of the tuned mass absorbers provided at the mid-span of the bridge deck because it affects the modal response quantities.

Said Elias, Vasant Matsagar

Chapter 9. Monitoring and Damage Detection of a 70-Year-Old Suspension Bridge – Ölfusá Bridge in Selfoss, Case Study

Ölfusá Bridge in South Iceland is located in the town of Selfoss on the ring road Route 1 in Iceland, approximately 50 km from Reykjavik. It is a suspension bridge across the Ölfusá glacial river and while being a very important link in the road transport network in Iceland, it also serves as a vital link for the community of Selfoss for both vehicles and pedestrians. Inspections of the main cables of the suspension bridge have indicated an inadequate level of safety due to corrosion, as well as significantly heavier traffic loads and increased self-weight due to rehabilitation of the bridge deck. A system identification of the bridge was conducted in 2012 and a permanent monitoring system was installed in 2014 with the aim of identifying changes in the structural performance of the bridge. The measurements have provided valuable information which are used in the operation of the bridge. The measured modal properties have been used to calibrate the FE models of the bridge, which are used for structural analysis and the structural reliability assessment of the bridge. The continuous monitoring of the cable forces gives the possibility of identifying changes in the structural response of the bridge in addition to the regular visual inspections.

Gudmundur Valur Gudmundsson, Einar Thor Ingólfsson, Kristján Uni Óskarsson, Bjarni Bessason, Baldvin Einarsson, Aron Bjarnason

Chapter 10. Performance of Base Isolated Bridges in Recent South Iceland Earthquakes

Since 1983, 15 Icelandic bridges have been base isolated for seismic protection. Lead-rubber bearings have been used in all cases. Nine of these bridges are located in the South Iceland Lowland, which is an active seismic zone where earthquakes of magnitude seven can be expected. In June 2000 two Mw6.5 earthquakes struck in the area and in May 2008 a Mw6.3 event hit the area again. Four of the base isolated bridges were located in the near-fault area of these earthquakes with a fault-to-site distance of less than 15 km, and most likely three of them were subjected to strong low-frequency near-fault velocity pulses. None of the bridges collapsed or were severely damaged and all of them were open for traffic immediately after these events. Post-earthquake response analysis has indicated that the base isolation was important for the performance of the bridges.

Bjarni Bessason, Einar Hafliðason, Guðmundur Valur Guðmundsson

Chapter 11. Cyclic Capacity of Dowel Connections

Dowel connections are most frequently used to join different types of precast elements in RC precast industrial buildings. Such connections are typically subjected to the following types of potential failure mechanism: (a) local failure characterized by the simultaneous yielding of the dowel and crushing of the surrounding concrete, and (b) global failure, characterized by spalling of the concrete between the dowel and the edge of the column or the beam. The strength corresponding to these two types of failure has been estimated using different procedures available in the literature with significantly different accuracy. While the strength corresponding to the local failure is estimated quite precisely, the strength corresponding to the global failure is typically considerably underestimated. The new procedure for the estimation of the global failure is proposed and described in the paper. It was evaluated based on the strut-and-tie model.

Tatjana Isakovic, B. Zoubek, M. Fischinger

Chapter 12. Ductile Knee-Braced Frames for Seismic Applications

This paper presents the behavior and design concept of efficient structural steel systems based on innovative applications of knee braces. Advantages of knee-braced frames (KBF) include relatively simple connections for ease of construction and reparability after an earthquake and less obstruction as compared to conventional bracing systems. Various configurations of KBFs can be designed and detailed for different levels of strength, stiffness, and ductility. KBFs are designed so that all inelastic activities are confined to the knee braces and designated yielding elements only. Key design concepts to ensure ductile behavior of KBFs are first summarized. Finally, results from experimental and analytical studies into the behavior of KBFs are briefly presented. The results show that KBFs can provide viable alternatives to conventional structural systems.

Sutat Leelataviwat, P. Doung, E. Junda, W. Chan-anan

Chapter 13. Seismic Capacity Reduction Factors for a RC Beam and Two RC Columns

Many building structures can be damaged and even collapse during a severe earthquake. For this reason it is important to take immediate decisions about the safety of damaged structures in order to avoid possible human losses in case of aftershocks. Therefore, a quantitative damage assessment should be made to estimate residual seismic capacity. Reinforced Concrete (RC) Frames are one of the most common earthquake resistant elements used in Argentina. Consequently, it was judged necessary to study the residual seismic capacity of the basic components of this structural type. Experimental results and numerical models of RC beams and columns were considered to establish the reduction factors for different damage classes. A beam tested by the authors and two columns reported in the bibliography were studied. The results were compared with the values suggested by the revised Japanese Guideline for Post-Earthquake Damage Evaluation and Rehabilitation (2014) and a satisfactory agreement was found between them.

Pablo Mariano Barlek Mendoza, Daniela Micaela Scotta, Enrique Emilio Galíndez

Chapter 14. Single-Degree-of-Freedom Analytical Predictive Models for Seismic Isolators

Single-degree-of-freedom constitutive relations aimed at modeling the mechanical response of seismic isolators, specifically lead-core bearing devices and elastomeric bearings, are discussed in this contribution. Two constitutive models are considered. For the lead-core bearings, a model that defines the relation between the shear displacement and the generated shear force is postulated. This model involves a hysteresis parameter the evolution of which is separately defined. The mechanical behavior of the elastomeric bearings I s modeled assuming a constitutive law that takes into account several interacting mechanisms including the mechanical damage accumulation. Numerical procedures are developed for both constitutive relations. These numerical procedures are to be implemented in detailed finite element models and accurate finite element analysis of base-isolated structures.

Todor Zhelyazov

Chapter 15. The Evaluation of Nonlinear Seismic Demands of RC Shear Wall Buildings Using a Modified Response Spectrum Analysis Procedure

In the standard Response Spectrum Analysis (RSA) procedure, the elastic force demands of all significant vibration modes are first combined and then reduced by a response modification factor (R) to get the inelastic design demands. Recent studies, however, have shown that it may not be appropriate to reduce the demand contributions of higher vibration modes by the same factor. In this study, a modified RSA procedure based on equivalent linearization concept is presented. The underlying assumptions are that the nonlinear seismic demands can be approximately obtained by summing up the individual modal responses, and that the responses of each vibration mode can be approximately represented by those of an equivalent linear SDF system. Using three high-rise buildings with RC shear walls (20-, 33- and 44-story high), the accuracy of this procedure is examined. The modified RSA procedure is found to provide reasonably accurate demand estimations for all case study buildings.

Fawad Ahmed Najam, Pennung Warnitchai

Chapter 16. Seismic Fragility Assessment of Reinforced Concrete High-Rise Buildings Using the Uncoupled Modal Response History Analysis (UMRHA)

In this study, a simplified approach for the analytical development of fragility curves of high-rise RC buildings is presented. It is based on an approximate modal decomposition procedure known as the Uncoupled Modal Response History Analysis (UMRHA). Using an example of a 55-story case study building, the fragility relationships are developed using the presented approach. Fifteen earthquake ground motions (categorized into 3 groups corresponding to combinations of small or large magnitude and source-to-site distances) are considered for this example. These ground motion histories are scaled for 3 intensity measures (peak ground acceleration, spectral acceleration at 0.2 s and spectral acceleration at 1 s) varying from 0.25 to 2 g. The presented approach resulted in a significant reduction of computational time compared to the detailed Nonlinear Response History Analysis (NLRHA) procedure, and can be applied to assess the seismic vulnerability of complex-natured, higher mode-dominating tall reinforced concrete buildings.

Muhammad Zain, Naveed Anwar, Fawad Ahmed Najam, Tahir Mehmood

Chapter 17. Ambient Vibration Testing of a Three-Storey Substandard RC Building at Different Levels of Structural Seismic Damage

In this paper, the effects of structural damage on the modal characteristics of a substandard full-scale reinforced concrete (RC) building were investigated. The RC building was a representative of large number of existing substandard RC buildings. The building was subjected to different levels of structural damage through quasi-static reversed cyclic lateral loading. Ambient vibration tests were carried out not only before and after quasi-static lateral loading cycles, but also at a certain damage level. The vibration test survey showed that modal frequencies decreased while damping ratios increased with the increasing levels of damage. More importantly, since the structural damage pattern due to quasi-static cyclic lateral loading was similar to ones observed in existing RC structures after earthquakes, determining the changes in dynamic characteristics at different levels of structural damage can be useful for estimating the residual performance of the structure after an earthquake.

Pinar Inci, Caglar Goksu, Ugur Demir, Alper Ilki

Chapter 18. System Identification of a Residential Building in Kathmandu Using Aftershocks of 2015 Gorkha Earthquake and Triggered Noise Data

System identification is conducted to estimate the fundamental vibration period and damping ratio of a residential building in Kathmandu. Ground motion and structural response due to aftershocks of the 2015 Gorkha Earthquake, as well as noise data triggered by ambient vibration is used to identify the dynamic properties of the structure. In total, motion due to 3 aftershocks and 362 ambient vibration is used. The identification is based on estimating the frequency response function of the structure. When using the aftershock data, this function is estimated from power spectral density functions of motion recorded at the ground floor and roof of the structure. In case of triggered noise, it is assumed that the input motion is a white noise. Fundamental vibration period is estimated from the first dominant peak of the transfer function, and damping ratio is estimated by using the half-power bandwidth. The building being studied is a 4-storey reinforced concrete frame with masonry infill walls. The fundamental period of the building estimated from aftershock data and triggered noise data was found to be similar in the range of 0.24–0.4 s. Empirical relations available on the literature predict a fundamental period of 0.25 s for the building being studied. It can thus be concluded that the fundamental period of the building can be estimated with confidence using both aftershock and ambient vibration data. The damping ratio, however, showed greater variation. This variation is, in part, due to the inherent uncertainty in spectral estimation which requires smoothing operations that directly affect the bandwidth of the dominant peak of frequency response function.

Yoshio Sawaki, Rajesh Rupakhety, Simon Ólafsson, Dipendra Gautam

Chapter 19. Damage Observations Following the Mw 7.8 2016 Kaikoura Earthquake

On 14 November 2016 a magnitude Mw 7.8 earthquake struck the upper South Island of New Zealand with effects also being observed in the capital city, Wellington. The affected area has low population density but is the largest wine production region in New Zealand and also hosts the main national highway and railway routes connecting the country’s three largest cities of Auckland, Wellington and Christchurch, with Marlborough Port in Picton providing connection between the South and North Islands. These transport facilities sustained substantial earthquake related damage, causing major disruptions. Thousands of landslides and multiple new faults were counted in the area. The winery facilities and a large number of commercial buildings and building components (including brick masonry veneers, historic masonry construction, and chimneys), sustained damage due to the strong vertical and horizontal acceleration. Presented herein are field observations undertaken days directly following the earthquake, with the aim to document earthquake damage and assess access to the affected area.

Dmytro Dizhur, Marta Giaretton, Jason M. Ingham

Chapter 20. Seismic Rehabilitation of Masonry Heritage Structures with Base-Isolation and FRP Laminates – A Case Study Comparison

The cultural and historical significance of architectural heritage buildings demands intrinsic considerations regarding appropriate conservation measures that need to be undertaken in order to restore or maintain their historical values. In this paper two contemporary seismic strengthening measures with varying degrees of invasiveness and strengthening efficiency are employed in a case study numerical simulation on a typical neo-renaissance masonry heritage building. The use of fibre reinforced polymer composites and the implementation of base-isolation was considered in the study in order to achieve the desired, code-based seismic protection levels. Non-linear static analyses with incremental increases in levels of seismic intensities were conducted on mathematical models of the fixed-base, FRP-strengthened and base-isolated variants of the structure. The comparison of results based on static pushover analyses for various ranges of seismic intensity was presented, while each strengthening measure was assessed in terms of its efficiency.

Simon Petrovčič, Vojko Kilar

Chapter 21. From Seismic Input to Damage Scenario: An Example for the Pilot Area of Mt. Etna Volcano (Italy) in the KnowRISK Project

In this paper we present a multidisciplinary approach aimed at assessing seismic risk regarding non-structural damage. The study has been carried out in the framework of the European KnowRISK Project and focuses on the pilot area of Mt. Etna volcano (Italy). Both instrumental data and as well as macroseismic observations provide unique opportunities for testing innovative and classical approaches for assessing seismic risk. Starting from the seismic hazard analysis, we first identify a test site (Zafferana) affected by non-structural damage. We produce seismic scenarios based on macroseismic and ground-motion data and finally obtain the relevant risk map using the Italian census data to classify buildings into vulnerability classes and a model to predict damage distribution.

Raffaele Azzaro, Salvatore D’Amico, Horst Langer, Fabrizio Meroni, Thea Squarcina, Giuseppina Tusa, Tiziana Tuvè, Rajesh Rupakhety

Chapter 22. Seismic Performance of Non-structural Elements Assessed Through Shake Table Tests: The KnowRISK Room Set-Up

In the scope of the KnowRISK research project a set of tests were carried out on the LNEC-3D shake table in order to assess the seismic performance of several non-structural elements and building contents. The aim was to create a room that was as realistic as possible, not only in terms of spatial arrangement but also in terms of furniture and decorative objects. This would allow the presence of daily-life objects and furniture that can represent hazard inside regular homes during an earthquake. Damages were observed with increasing intensity seismic motions. In some of the tests different non-structural protective measures were implemented in order to observe how they mitigate the damage. Videos of the entire set-up were recorded during the tests, for the KnowRISK interventions, and accelerations were measured in a wardrobe and a bookcase. This allowed to obtain qualitative as well as quantitative data about the objects’ seismic performance.

Paulo Candeias, Marta Vicente, Rajesh Rupakhety, Mário Lopes, Mónica Amaral Ferreira, Carlos Sousa Oliveira

Chapter 23. KnowRISK Practical Guide for Mitigation of Seismic Risk Due to Non-structural Components

Good performance of non-structural elements can be decisive in saving lives and costs when an earthquake strikes. The European project KnowRISK aims to educate and encourage households to take the necessary precautionary measures to protect people, houses, and contents. Preparedness and prevention act on community resilience. Within the KnowRISK project, the idea of a Practical Guide has been conceived suggesting seismic mitigation solutions for non-structural components to non-experts stakeholders. It is intended to guide people into the first steps of prevention in a straightforward manner, minimizing or avoiding injuries, damage, and long-term financial consequences. The novelty of the Guide belongs to his philosophy: a path through increasing challenges corresponds to a growing level of safety. The idea is that anyone can mitigate seismic risk in its own environment by adopting simple and low cost measures. The Practical Guide may contribute to increase risk awareness. This kind of initiatives if undertaken at larger scales may also enhance social resilience.

Hugo O’Neill, Mónica Amaral Ferreira, Carlos Sousa Oliveira, Mário Lopes, Stefano Solarino, Gemma Musacchio, Paulo Candeias, Marta Vicente, Delta Sousa Silva

Chapter 24. A Study of Rigid Blocks Rocking Against Rigid Walls

The safety of typical bookshelf is investigated using an inverted pendulum approach. A general bookcase is modelled as a rocking block and its response to damped harmonic excitation is simulated. The rocking of the block is considered as one sided since these household items generally stand parallel to a wall. This approach adds restraints to the rocking behaviour. The overturning spectra for the bookcase is presented for one-sided and two-sided rocking for a range of damped harmonic excitations, demonstrating the chaotic behaviour of the inverted pendulum model. Furthermore, results indicate one-sided rocking to be more prone to overturning, making it a more unstable system than its two-sided counterpart.

Gudmundur Örn Sigurdsson, Rajesh Rupakhety, Símon Ólafsson

Chapter 25. Finite Element Model Updating of a Long Span Suspension Bridge

Errors and uncertainties in numerical models of structures affects the ability of these models to accurately predict the dynamic behaviour. However, model updating techniques can be used to calibrate the models based on experimental data. This paper presents a case study of sensitivity-based model updating applied to the Hardanger Bridge, a long span suspension bridge. Thirteen stiffness and mass parameters are chosen to represent the system uncertainties in a finite element (FE) model. Thirty vibration modes from system identification based on acceleration data is used to calibrate the FE model, using identified natural frequencies and mode shapes as objectives. In the updated model the average error in natural frequencies is reduced from 3.65% to 1.28%. The MAC numbers for the updated modes range from 0.678 to 0.999. The study indicates FE models of large suspension bridges can be significantly improved, but many uncertainties related to modelling simplifications are still present.

Øyvind Wiig Petersen, Ole Øiseth

Chapter 26. Characterization of the Wave Field Around an Existing End-Supported Pontoon Bridge from Simulated Data

The environmental excitation and the dynamic response are currently being monitored on the Bergsøysund Bridge, an existing end-supported pontoon bridge. Wave radars are monitoring the one-point sea surface elevation at six different locations. As the wave excitation is considered the main concern for vibration-based design of similar bridges, an appropriate description of the sea state characterizing the wave excitation is crucial. Furthermore, it is considered a necessity for an assessment of the quality of response predictions by comparison with measurements. In the current paper, time simulations of wave elevation are used to identify the already-known sea states. The Fourier Expansion Method (FEM) and Extended Maximum Entropy Principle (EMEP) are applied for this purpose. The results provide valuable insights about both the identification methods and the sensor layout.

Knut Andreas Kvåle, Ole Øiseth

Chapter 27. Identification of Rational Functions with a Forced Vibration Technique Using Random Motion Histories

Rational Functions are used to describe the self-excited forces acting on the bridge deck in the time domain. They can be identified indirectly based on aerodynamic derivatives or directly with the free (E2RFC method) or forced vibration technique, which can significantly decrease the testing time. The approach presented herein enables the extraction of Rational Function Coefficients by testing the section model at only one wind speed. This aim is achieved by increased complexity of the forced motion compared to the previous tests, which made it possible to test a wider range of reduced velocities by adjusting the motion frequency. In this study, motion histories generated from the assumed flat spectra are used. Wind tunnel tests on a streamlined section model utilizing simultaneous vertical, horizontal and torsional vibrations were performed to extract Rational Function Coefficients associated with 3-degree-of-freedom motion. Restrictions and improvements arising from the proposed methodology are described.

Bartosz Siedziako, Ole Øiseth

Chapter 28. The Dynamic Intelligent Bridge: A New Concept in Bridge Dynamics

A method is put forward for designing bridges with improved performance under extreme dynamic loadings, such as strong earthquakes. The basic idea is that varying the boundary conditions can lead to an improved structural performance under dynamic actions. The specific goal is to substitute current bridge joints that have a fixed width with variable-width joints, which initially can be either closed or open depending on their length and the serviceability requirements, while under seismic loading their width is optimised either with a one-off adjustment, or continuously varying through semi-active control. In all cases, a novel device is used that permits this improved behaviour of the joints, the moveable shear key (MSK), a device for blocking the movement of the bridge deck, which is not permanently fixed to the seat of the abutment but can slide, hence opening a previously closed gap or closing an existing gap between the deck and the abutment. The performance sought by varying the joint gap depends on the design objectives. A pilot study on the effect of gap size is also presented, which illustrates that it can significantly affect the response quantities of the abutments.

Andreas J. Kappos

Chapter 29. Systematic Methodology for Planning and Evaluation of a Multi-source Geohazard Monitoring System. Application of a Reusable Template

In this paper geohazards and their monitoring are considered in the general context of reservoirs and dams. A systematic methodology is used to identify and characterise multiple causes and effects, as well as their interdependencies. This methodology originated at NASA as a part of the safety management of the space program. Here, a recently presented, multi-system expansion of the method is introduced, which has been used to capture complicated data into a reusable template represented by interrelation matrices. This template has a general relevance for monitoring geohazards considering the safety of reservoirs and dams. The methodology and the related system analysis possesses some powerful diagnoses possibilities. The template is for instance, used to reveal the potential safety value of a multi-source system installed for monitoring geohazards in conjunction with a large reservoir in Iceland. The method presents an important step in a holistic risk and safety management of reservoirs.

Fjóla G. Sigtryggsdóttir, Jónas Th. Snæbjörnsson

Chapter 30. How to Survive Earthquakes: The Example of Norcia

In this paper lessons are extracted from the comparison between the very different consequences that similar earthquakes had on the neighbouring towns of Norcia and Amatrice during the 2016 seismic crisis of central Italy. It was found that the differences in damage were essentially due to the strengthening of most houses in Norcia done during the previous decades. This is also likely to lead to a much faster recover of the economy and livelihood in Norcia, as Amatrice needs to be entirely rebuilt.

Mário Lopes, Francisco Mota de Sá, Mónica Amaral Ferreira, Carlos Sousa Oliveira, Cristina F. Oliveira, Fabrizio Meroni, Thea Squarcina, Gemma Musacchio

Chapter 31. KnowRISK on Seismic Risk Communication: The Set-Up of a Participatory Strategy- Italy Case Study

KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) is a European project that addresses prevention measures to reduce non-structural damage caused by earthquakes. It is built on risk communication and takes action on pilot areas of the three participating countries: Portugal, Iceland, and Italy. The setting up of risk communication strategies in the project stands on the understanding local communities fragility, on their direct engagement, and on a holistic approach to vulnerability. The level of relevance of seismic compared to other hazards, the understanding, the memory of past disasters are indicators that affect the way a risk is perceived and preventive measures are taken. Similarly, the level of education, wealth, exposure to other, social, risks are aggravation parameters in risk computation to be accounted for when we communicate risk. Strategies for risk communication in KnowRISK rely on schools and citizen’s engagement, citizen’s science activities, tools for raising awareness.

Gemma Musacchio, Susanna Falsaperla, Stefano Solarino, Giovanna Lucia Piangiamore, Massimo Crescimbene, Nicola Alessandro Pino, Elena Eva, Danilo Reitano, Federica Manzoli, Michele Fabbri, Mariangela Butturi, Mariasilvia Accardo

Chapter 32. Seismic Risk Communication: How to Assess It? The Case of Lisbon Pilot-Area

This paper aims to present and discuss the theory and research strategy underlying the assessment of the KnowRISK risk communication in one of the KnowRISK pilot-areas, Alvalade parish in Lisbon city. The theory guiding this evaluation research stands on Precaution Adoption Process Model (PAPM), and is complemented by other proposals. Defining the most appropriate research design required answers to two basic questions: ‘what to assess?’ and ‘how to assess?’. The first-mentioned question implied to take into account KnowRISK risk communication main aims, clarifying which cognitive and behavioral changes were realistically expectable in the context of an earthquake dormant society as is the case of Lisbon. Concerning the second-mentioned question, the assessment of risk communication procedure stands in an evaluation research design that comprehends quantitative and qualitative methods.

Delta Sousa e Silva, A. Pereira, Marta Vicente, R. Bernardo, Monica Amarel Ferreira, Mario Lopes, Carlos Sousa Oliveira

Chapter 33. Shaping Favorable Beliefs Towards Seismic Protection Through Risk Communication: A Pilot-Experience in Two Lisbon Schools (Portugal)

Communicating science within disaster risk reduction using methods that encourage two-way dialogue between scientists and laypersons is a challenging task. This paper aims at presenting a methodological strategy of communicating risk and non-structural seismic protection measures through participatory approach. Such methodological strategy is part of a pilot experience of risk communication in two schools in Lisbon (Portugal) under the EU project KnowRISK (Know your city, Reduce seISmic risK through non-structural elements). The efficacy of education for seismic safety is often inhibited by an incomplete understanding of the process by which individuals decide to protect themselves from harm (Becker JS, Paton D, Johnston DM, Ronan KR. Nat Hazards 64(1):107–137, 2012a; Becker JS, Paton D, Johnston DM, Ronan KR. J Civil Eng Archit 6(6):673–681, 2012b). Becker et al. (in ibid) conceive such a process composed of a series of stages: knowledge and awareness, thinking and talking, understanding the consequences, developing skills. The above-mentioned pilot experience of risk communication was designed in order to trigger the cognitive process underlying behavioral change. Lisbon is a dormant society as far as earthquake risk is concerned. Given this, risk communication was firstly designed to generate awareness and knowledge among target-groups.

Delta Sousa e Silva, Marta Vicente, A. Pereira, R. Bernardo, Paulo Candeias, Monica Amarel Ferreira, Mario Lopes, Carlos Sousa Oliveira, P. Henriques

Chapter 34. The KnowRISK Action for Schools: A Case Study in Italy

“Know your school: be safe!” is a risk communication campaign, within the KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) project, involving schools in three European countries, namely Portugal, Italy and Iceland. Its main aim is to facilitate school communities’ access to experts’ knowledge on non-structural seismic risk reduction. In Italy we implemented a learning strategy to capture young people attention. We believe students will be influential in turning scientific knowledge to practical know-how. The strategy is based on Situated Learning Episode (EAS), where homework is for learning and skills, and classwork is for reworking and understanding. The KnowRISK-EAS starts and ends with two focus groups where students, and experts rework concepts and discuss best practices. Students are asked to implement a communication product addressing their peers. The assignment has a double goal: it helps to activate reflexive learning; it will be a project tool to trigger risk reduction attitude within schools communities.

Gemma Musacchio, Elena Eva, Giovanna Lucia Piangiamore

Chapter 35. Risk Perception and Knowledge: The Construction of the Italian Questionnaire to Assess the Effectiveness of the KnowRISK Project Actions

In this paper we describe the design of the Italian version of the KnowRISK (EU project Know your city, Reduce seISmic risK through non-structural elements) questionnaire. Purpose of the questionnaire is to evaluate if the actions of the KnowRisk project can promote in students and in the people involved, attitudes and behaviours to reduce seismic risk. In the first months of the KnowRisk project, a questionnaire was designed to assess the starting point (T0) on seismic risk Perception, Knowledge of risk and Practice (PKP) of students and public in general before the project actions. Practice was meant in terms of intention to act. The first versions of the KnowRISK questionnaire were built around four theme questions: Who are you?; Do you feel safe?; What do you risk? What would you do?. We also present a preliminary data analysis of the answers collected between March 29 2016 and May 12 2016 in three schools (one each) of the Lombardia (N = 127), Lazio (N = 24) and Liguria regions (N = 14) for a total of 165 students. From this experience, we derived the guidelines for the construction of a common questionnaire of the KnowRISK project: (a) to assess in different countries the effectiveness of a project it is preferred to have a common questionnaire; the questionnaire should consider both qualitative and quantitative aspects. In this regard it is helpful to use Likert scales and methods such as the semantic differential that consider both aspects and they allow quantitative scores which are amenable to sophisticated statistical data analysis; (c) there are three important dimensions to assess project effectiveness: perception; knowledge; and intention to act to reduce the risk.

Massimo Crescimbene, Nicola Alessandro Pino, Gemma Musacchio

Chapter 36. Awareness on Seismic Risk: How Can Augmented Reality Help?

To communicate the importance of knowing the risk of non-structural damage caused by earthquakes, we developed applications based on Augmented Reality (AR) features. These applications run on mobile devices, such as tablets and smartphones, by using their video camera and other on-board sensors, such as GPS, accelerometer, and gyrocompass, from which AR users do take advantage. Combined with a specifically designed exhibit, our AR applications can contribute to increase the common awareness on seismic risk, providing useful information on how to have safer homes in case of an earthquake. Building codes do not take into account non-structural elements, leaving communities at risk of injuries, blocking escapes and even causing deaths. In this framework, the personal preparedness is of paramount importance. The development of our AR applications is supported by the European project KnowRISK (Know your city, Reduce seISmic risK through non-structural elements).

Danilo Reitano, Susanna Falsaperla, Gemma Musacchio, Riccardo Merenda

Chapter 37. Development of a Common (European) Tool to Assess Earthquake Risk Communication

This paper reports work on an on-going EC project called KnowRISK aimed at reducing the seismic risk from non-structural elements in buildings. Specifically it reports work on the development of a European tool to assess the effectiveness of risk communication interventions and awareness raising training with middle and high school children in case study areas in Portugal, Italy and Iceland. It describes the difficulties research teams faced in agreeing a theoretical framework and in devising the survey tool. Although they all agreed it was essential to have a common survey if the findings from the research were to be compared across the three countries, one year into the two-year project two of the teams were moving in different directions. This was significant since some of the pre-intervention surveys had already been conducted. Both theoretical frameworks had merit and each of the questionnaires were capable of assessing the efficacy of the training. However, they were in no way comparable. Finally the paper details how these difficulties were resolved and a common questionnaire was devised that embodied virtues from both surveys. This was then applied in all three countries to provide comparable data, the findings from which will be reported elsewhere.

Stephen Platt, Gemma Musacchio, Massimo Crescimbene, Nicola Alessandro Pino, Delta S. Silva, Mónica A. Ferreira, Carlos S. Oliveira, Mário Lopes, Rajesh Rupakhety
Additional information

Premium Partner

image credits