"Fragility curves are useful tools for reliability evaluation of structures as well as for identifying the most vulnerable components. This study focuses on the seismic fragility analysis of highway bridges. Two main approaches are used for this purpose: component-based and system-based fragility analyses. The seismic vulnerability of two existing bridges located in Montreal are assessed as case studies.The main goal of this study is to develop reliable seismic fragility curves for highway bridge structures considering all significant uncertainties involved. Uncertainties include those associated with modelling structural behavior, seismic inputs and definition of component capacities. The procedures are implemented for the fragility assessment of two existing bridges as case studies. For this purpose, deterioration due to corrosion of reinforcing steel and its effects on structural behavior are included, as well as validation of the Finite Element Model using dynamic properties obtained from ambient noise measurements. Proposed methods for the selection of appropriate set of ground motion records, the type of model analysis and probabilistic modeling of component capacities are presented and illustrated for the two case studies.Two stochastic methods are proposed for validating the Finite Element Model of a bridge. The first method is based on classical hypothesis testing procedures while the second uses a Bayesian updating approach. The stochastic methods are also used to update the input parameters, detect probable major damage in the bridges and determine the confidence interval on model responses as a function of laboratory test data and field observations.In order to limit the uncertainties involved in seismic inputs, a state-of-the-art ground motion record selection procedure based on Conditional Mean Spectrum (CMS) is used. Incremental Dynamic Analysis (IDA) is performed to evaluate the record to record variability in seismic responses and to capture the nonlinearity in structural component behaviors.The first part of the thesis describes the application of component-based fragility analysis for the seismic vulnerability assessment of highway bridge structures. IDA is performed on the validated Finite Element model of the structure using an appropriate set of ground motion records. The results are used for estimating the relationships between ground motion intensity measures and component demands. A Joint Probabilistic Seismic Demand Model (JPSDM) is fitted to the results in order to develop component and system fragility curves of the structure.Since the component based fragility analysis of complex structures comprising a large number of components requires enormous computational efforts, in the second part of this study, a system-based approach for developing seismic system fragility curves is proposed which uses Support Vector Machines (SVM). SVM is a state-of-the-art machine learning technique which is used to discover patterns in highly dimensional and complex data sets. In this application, SVM is used to determine the relationship between ground motion intensity measures and peak structural responses. Seismic fragility curves are developed using Probabilistic SVM (PSVM). Finally, the efficiency of the proposed PSVM method for its application to vector-valued ground motion Intensity Measures (IM) as well as traditional single-valued IM are investigated." --

Curved bridges are constructed to conform to geometric constraints resulting from traffic and structural restrictions. They are different from their straight counterparts since the response coupling in the longitudinal and transverse directions and rotation of the superstructure may lead to significantly different seismic response. Observations from past earthquakes highlighted the seismic vulnerability of these bridges due to this coupled response. The consequence of bridge damage on the performance of transportation system is commonly assessed through Seismic Risk Assessment (SRA) of lifeline systems. Thus, seismic fragility curves are essential input to SRA to estimate damage to highway bridges and consequently to the network. The literature review shows shortcomings in fragility studies on the effect of horizontal curvature of bridges, specifically concrete box-girder bridges. This study aims to fill in the gap on the current state-of-the-knowledge in the seismic response and vulnerability of curved concrete box-girder bridges. Since this bridge type is common in California, the modern details adopted by CALTRANS along with the current seismic design considerations from SDC (2013) are used to select the representative benchmark bridges. To incorporate the uncertainty in geometrical, structural, and material properties of bridges into the analytical models, five sets of statistical bridge samples (each includes 160 bridges) with various subtended angles are developed. These bridge models are subjected to four sets of ground motions representing different site soil conditions and spectral characteristics. A total of 800 response history analyses are performed and the results are used to develop analytical component and system fragility functions for a range of subtended angles. A comprehensive study on the effect of horizontal curvature on the bridge dynamic characteristics and component seismic response is conducted. The median of system (bridge) fragility curves are proposed as a function of the subtended angle for each ground motion set. These functions can be used as input into SRA tools. The fragility analysis shows that the seismic vulnerability of bridges depends on the soil condition of the site and ground motion characteristics as well as the horizontal curvature of the bridge. Columns are found to have the most significant contribution to the system fragility curves. The analyses confirm that the current seismic details including PTFE/spherical bearings and isolated shear keys, suggested by CALTRANS, achieve the objectives of capacity-protected design of piles. Since the dynamic characteristics of bridges are sensitive to the curvature, curved bridges with subtended angles greater than 30 degrees require explicit modeling of curved geometry. In curved bridges, the coupling of transverse and longitudinal modes reduces the dominance of the fundamental mode in the bridge response and leads to the contribution of higher modes. The statistical evaluation of structural demands indicates that the curvature and the torsion demands on columns are amplified in curved bridges.

The Proceedings of the NATO Advanced Study Institute on Analysis and Design of Bridges held at ~e§me, lzmir, Turkey from 28 June 1982 to 9 July 1982 are contained in the present volume. The Advanced Study Institute was attended by 37 lecturers and participants from 10 different countries. The Organizing Committee consisted of Professors P. Gtilkan, A. C. Scordelis, S. T. Wasti and 9. Yl. lmaz. The guidelines set by NATO for the Advanced Study Institute require it to serve not only as an efficient forum for the dissemination of available advanced knowledge to a selected group of qualified people but also as a platform for the exploration of future research possibilities in the scientific or engineering areas concerned. The main topics covered by the present Advanced Study Institute were the mathematical modelling of bridges for better analysis and the scientific assessment of bridge behaviour for the introduction of improved design procedures. It has been our observation that as a result of the range and depth of the lectures presented and the many informal discussions that took place, ideas became fissile, the stimulus never flagged and many gaps in the engineering knowledge of the participants were "bridged". Here we particularly wish to mention that valuable informal presenta tions of research work were made during the course of the Institute by Drs. Friedrich, Karaesmen, Lamas and Parker.

This book presents a simplified approach to earthquake engineering by developing the fragility curve for regular and irregular moment-resisting frames based on different types of structural material, height, and ground motion records. It examines six sets of concrete and steel frames, which vary in terms of their height (3-, 6- and 9-storey) and include regular and irregular frames. Each structure frame was designed based on Eurocode 2 and 3 with the aid of Eurocode 8 for earthquake loading. The SAP2000 software was used as the main tool for the pushover analysis and incremental dynamic analysis. Readers are first provided with background information on the development of nonlinear analysis in earthquake engineering. Subsequently, each chapter begins with a detailed explanation of the collapse of the structures and the application in nonlinear analysis. As such, the book will greatly benefit students from both public and private institutions of higher, particularly those who are dealing with the subject of earthquake engineering for the first time. It also offers a valuable guide for Civil Engineering practitioners and researchers who have an interest in structural and earthquake engineering.

This book is a collection of select papers presented at the Tenth Structural Engineering Convention 2016 (SEC-2016). It comprises plenary, invited, and contributory papers covering numerous applications from a wide spectrum of areas related to structural engineering. It presents contributions by academics, researchers, and practicing structural engineers addressing analysis and design of concrete and steel structures, computational structural mechanics, new building materials for sustainable construction, mitigation of structures against natural hazards, structural health monitoring, wind and earthquake engineering, vibration control and smart structures, condition assessment and performance evaluation, repair, rehabilitation and retrofit of structures. Also covering advances in construction techniques/ practices, behavior of structures under blast/impact loading, fatigue and fracture, composite materials and structures, and structures for non-conventional energy (wind and solar), it will serve as a valuable resource for researchers, students and practicing engineers alike.