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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Artificial Neural Network Based Multi-Dimensional Fragility Development of Skewed Concrete Bridge Classes</title>
      <link>https://trid.trb.org/View/1505660</link>
      <description><![CDATA[Recent researches are directed towards the regional seismic risk assessment of structures based on a bridge inventory analysis. The framework for traditional regional risk assessments consists of grouping the bridge classes and generating fragility relationships for each bridge class. However, identifying the bridge attributes that dictate the statistically different performances of bridges is often challenging. These attributes also vary depending on the demand parameter under consideration. This paper suggests a multi-parameter fragility methodology using artificial neural network to generate bridge-specific fragility curves without grouping the bridge classes. The proposed methodology helps identify the relative importance of each uncertain parameter on the fragility curves. Results from the case study of skewed box-girder bridges reveal that the ground motion intensity measure, span length, and column longitudinal reinforcement ratio have a significant influence on the seismic fragility of this bridge class.]]></description>
      <pubDate>Tue, 29 May 2018 16:04:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1505660</guid>
    </item>
    <item>
      <title>Statistical assessment of seismic fragility curves for steel jacket platforms considering global dynamic instability</title>
      <link>https://trid.trb.org/View/1501647</link>
      <description><![CDATA[Many probabilistic studies in the field of offshore structures assume that the drift demand distributes lognormally around its median at all the intensity levels. However, this assumption may not be formally validated, and the purpose of this study is to investigate the assumption of lognormal distribution of the drift demand for the fixed offshore platforms, using Anderson–Darling goodness of fit test. The lognormal hypothesis for the drift demand can be investigated at two different regions as: (1) low intensity levels without any collapse case and (2) higher intensity levels with collapse cases. To this end, both the sample median and sample geometric mean are considered as the estimators of lognormal central tendency. The results indicate that the lognormal hypothesise is accepted based on the sample geometric mean at all the intensity levels. Nevertheless, the lognormal hypothesise is rejected at some intensity levels if the sample median is the central estimator.]]></description>
      <pubDate>Mon, 30 Apr 2018 09:19:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1501647</guid>
    </item>
    <item>
      <title>Probabilistic structural integrity evaluation of a highway steel bridge under unknown trucks</title>
      <link>https://trid.trb.org/View/1499100</link>
      <description><![CDATA[This paper presents fragility curves derived from a best-fit regression model that enable to quantify probabilistic structural integrity of an in-service highway steel bridge under multiple truck passages with uncertain characteristics. The regression model is able to be identified via analytical modelling techniques incorporating the bridge response quantities resulting from unknown five-axle trucks through structural health monitoring system. These quantities coupled with weigh-in-motion (WIM) data obtained from two weigh stations closest to the bridge are used (1) to identify which unknown trucks are presumably to travel over the bridge and (2) to quantify the plausible characteristics of the trucks and the corresponding load ratings determined following the AASHTO Manual. With this information, the regression models can be made to demonstrate load ratings as the truck characteristics change. Based on the best-fitted load ratings, nine significant truck characteristics were looked at in their role in causing a below satisfactory bridge capacity. Key findings reveal that the all axle weights affect the fragility curves though the axle weights are not significantly different, and the most significant axle spacing is the first spacing.]]></description>
      <pubDate>Mon, 23 Apr 2018 16:44:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1499100</guid>
    </item>
    <item>
      <title>Uncertainty and Dependence Analysis of Performance Limit State for Structural Multidimensional Fragility Evaluation</title>
      <link>https://trid.trb.org/View/1464912</link>
      <description><![CDATA[Considering uncertainty and dependence of performance limit states (PLSs), the study addresses a methodology to evaluate multidimensional fragility. The purpose is to identify the PLS uncertainty quantitatively. The dependence between each PLS parameters is also investigated. The limit state band is firstly proposed to describe the bi-dimensional case. Through interval estimation, the band area with a certain confidence level is determined. A reinforcement concrete bridge is used as example to illustrate the proposed approach for developing fragility curves. PLS threshold samples are obtained to formulate limit state function using incremental dynamic analysis. The study investigates the sensitivity of the method for fragility assessment when different confidence levels are considered. In addition, influence of correlation coefficient between PLSs is evaluated. Results show that a fragility interval is obtained with the introduction of limit state band. The interval length decreases as with the reduction of the confidence level. The probability of failure becomes smaller when the dependence between PLSs is ignored, which will result in overestimation of the structural seismic performance.]]></description>
      <pubDate>Fri, 28 Apr 2017 10:40:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1464912</guid>
    </item>
    <item>
      <title>Analytical Fragility Curves for Non-skewed Highway Bridges in Chile</title>
      <link>https://trid.trb.org/View/1464998</link>
      <description><![CDATA[Recent earthquakes in Chile and worldwide have caused significant economic losses due to the damage on the road bridge network. To conduct seismic risk assessment studies and to improve resilience of bridges, seismic vulnerability studies are required. The main objective of this study is to construct fragility curves of typical non-skewed highway bridges in Chile. The fragility curves are obtained from an incremental dynamic analysis of a two-dimensional model of the bent cap of a two-span simply supported underpass. As most bridges are constructed with seismic tie-down bars, their constitutive behavior was obtained experimentally. A total of five seismic bar specimens were tested to characterize their cyclic behavior in bridges with and without transverse diaphragms. The incremental dynamic analysis was performed with the two horizontal components of seven seismic records obtained from the Mw 8.8, 2010 Chile earthquake. Additionally, a parametric study is conducted to assess the seismic behavior of bridges with different configurations of seismic bars, with lateral stoppers, and with varying length of the transverse seat width. Results from this study reveal that seismic bars have a limited contribution to the seismic performance of the studied bridge, especially when lateral stoppers are incorporated. Additionally, the transverse seat width is found to be critical to reduce the collapse probability of the superstructure. The provided fragility curves may be used for seismic risk assessment and to evaluate possible improvements in seismic bridge design codes.]]></description>
      <pubDate>Fri, 28 Apr 2017 10:40:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1464998</guid>
    </item>
    <item>
      <title>Monte Carlo–Based Approach to Estimating Fragility Curves of Floating Docks for Small Craft Marinas</title>
      <link>https://trid.trb.org/View/1455172</link>
      <description><![CDATA[As a result of damage from the 2010 Chile and 2011 Japanese teletsunamis, tsunami risk to small craft marinas along the West Coast of the United States has become an important concern. This paper outlines an assessment tool that can be used to quantify the tsunami damage potential in small craft harbors. The methodology is based on the demand and capacity of a floating dock system and uses a Monte Carlo framework to address the uncertainty of input parameters. Detailed numerical modeling and damage calibration data from recent tsunamis are used to benchmark the approach. Results are provided as fragility curves and give a quantitative assessment of survivability. This tool yields an indication as to the survivability and/or failure of a floating dock system of vessels and floating components/piles subject to tsunami events. The objective of the presented effort is to quickly evaluate whether a floating dock is likely to survive or be destroyed by a particular tsunami scenario.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1455172</guid>
    </item>
    <item>
      <title>The Effect of Different Intensity Measures and Earthquake Directions on the Seismic Assessment of Skewed Highway Bridges</title>
      <link>https://trid.trb.org/View/1447247</link>
      <description><![CDATA[In this study the probable seismic behavior of skewed bridges with continuous decks under earthquake excitations from different directions is investigated. A 45° skewed bridge is studied. A suite of 20 records is used to perform an Incremental Dynamic Analysis (IDA) for fragility curves. Four different earthquake directions have been considered: -45°, 0°, 22.5°, 45°. A sensitivity analysis on different spectral intensity meas ures is presented; efficiency and practicality of different intensity measures have been studied. The fragility curves obtained indicate that the critical direction for skewed bridges is the skew direction as well as the longitudinal direction. The study shows the importance of finding the most critical earthquake in understanding and predicting the behavior of skewed bridges.]]></description>
      <pubDate>Thu, 26 Jan 2017 17:05:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1447247</guid>
    </item>
    <item>
      <title>Seismic vulnerability assessment of pile-supported wharves using fragility curves</title>
      <link>https://trid.trb.org/View/1323967</link>
      <description><![CDATA[In this study, the seismic vulnerability of a pile-supported wharf is assessed. Due to common lack of empirical data, the analytical fragility curves are developed using the results of the dynamic analysis of wharf subjected to the different time histories. Fragility curves are developed considering three engineering demand parameters, including displacement ductility factor (μd), differential settlement between deck and behind land and normalised residual horizontal displacement (NRHD). A sensitivity analysis using both the first-order second-moment method and the tornado diagram analysis is then carried out to evaluate the effects of uncertainties associated with geotechnical parameters in the seismic performance of the wharf. Adopted fragility curves are useful to seismic risk assessment. They can also be used to optimise wharf-retrofit methods. The results of sensitivity analysis demonstrate that uncertainties associated with the permeability of hydraulic placed sand fill contribute most to the variance of both NRHD and μd. While in the case of differential settlement, the friction angle of rock fill contributes most to the variance.]]></description>
      <pubDate>Fri, 10 Oct 2014 08:55:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1323967</guid>
    </item>
    <item>
      <title>Reliability Analysis of a Circular Bridge Pier Subject to Intentional Vehicular Impact</title>
      <link>https://trid.trb.org/View/1315288</link>
      <description><![CDATA[Bridges are vital to any transportation infrastructure and have the potential to highly impact an economic network if damaged and/or inaccessible. One of the major components in a bridge system is the bridge pier, which has to support several loading scenarios. This study focuses on the reliability of a reinforced concrete bridge pier subject to vehicular impact loading, which is designated as a hazardous load. Hazardous loads are typically high-intensity loads that are short in duration. These types of loads are receiving increased attention due to recent occurrences and their ability to initiate structural failure. To study the reliability of the bridge piers under this loading, Monte Carlo simulation is used in a first-order, second-moment reliability analysis on several column resistance and impact event combinations. The reliability analysis is carried out for five different vehicle classes to represent the likely vehicles to participate in the impact event. Additionally, sensitivity analysis is carried out to identify the factors that most contribute to high probabilities of failure: reinforcement area, vehicle speed, and vehicle mass. Fragility curves are generated to provide a graphical representation of the sensitivity analysis.]]></description>
      <pubDate>Mon, 04 Aug 2014 18:46:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1315288</guid>
    </item>
    <item>
      <title>Procedure for determining the seismic vulnerability of an irregular isolated bridge</title>
      <link>https://trid.trb.org/View/1243842</link>
      <description><![CDATA[A seismic vulnerability procedure, based on the capacity/demand ratio approach, is applied to an irregular isolated bridge. Special features are incorporated in both, demand estimation and capacity evaluation. The seismic demand is represented by an average pseudo-acceleration spectrum derived from 159 earthquake accelerograms recorded in the region where the bridge is located. The capacity spectrum method is adopted for estimating the structural expected performance for several limit states. The capacity curve derived from a static non-linear procedure is obtained by means of a lateral load pattern that follows the displacement configuration, previously assessed by the use of time history analyses of the bridge supported on non-linear isolator bearings. Based on a moment–curvature analysis of the pier's sections, the maximum curvature ductility was established for each of the four defined performance limit states. Finally, probability density functions of the bridge capacity and demand were assessed and fragility curves were proposed aimed at determining the expected behaviour of the bridge as function of peak ground acceleration (PGA) of the typical strong motions recorded in the area.]]></description>
      <pubDate>Fri, 29 Mar 2013 09:55:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1243842</guid>
    </item>
    <item>
      <title>Time-dependent seismic fragility curves on optimal retrofitting of neutralised reinforced concrete bridges</title>
      <link>https://trid.trb.org/View/1217467</link>
      <description><![CDATA[The neutralisation (carbonation) of concrete usually results in material deterioration of a reinforced concrete (RC) bridge, so that the seismic capacity of the structure tends to degrade over time. This paper determined the deteriorated plastic hinge properties of the neutralised RC bridge column and performed the pushover analysis to obtain the decayed seismic capacity curves. As a result, the time-dependent fragility curves with respect to some representative damage levels can be established and the possible seismic loss can be expressed as a function of service time. The S-surfaces representing retrofitting cost versus service time for a neutralised RC bridge subjected to different earthquake levels were determined quantitatively in a case study. Throughout the whole life-cycle of a bridge, critical service times corresponding to dramatically increased slopes in the S-surface associated with cost elevations can be identified to assist in the development of a financially optimised strategy for timely seismic retrofitting.]]></description>
      <pubDate>Thu, 15 Nov 2012 12:33:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1217467</guid>
    </item>
    <item>
      <title>Seismic fragility analysis of highway bridges considering multi-dimensional performance limit state</title>
      <link>https://trid.trb.org/View/1146856</link>
      <description><![CDATA[Fragility analysis of highway bridges is increasingly important as part of the risk assessment of highway transportation networks exposed to seismic hazards. A methodology is introduced to calculate fragility that considers multi-dimensional performance limit state parameters. The study makes a first attempt to develop fragility curves for a multispan continuous (MSC) concrete girder bridge considering two performance limit state parameters: column ductility and transverse deformation in the abutments. The main purpose of the study is to show that the performance limit states, which are compared with the seismic response parameters in the calculation of fragility, should be properly modeled as randomly interdependent variables instead of deterministic quantities. The sensitivity of fragility curves is also investigated when the dependency between the limit states is different. Results indicate that the proposed method can be used to describe the vulnerable behavior of bridges which are sensitive to multiple response parameters. The fragility information generated by this method will be more reliable and likely to be implemented into transportation network loss estimation.]]></description>
      <pubDate>Wed, 22 Aug 2012 15:36:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1146856</guid>
    </item>
    <item>
      <title>Seismic Vulnerability Assessment of Highway Bridges Considering Ground Motion Directionality</title>
      <link>https://trid.trb.org/View/1122138</link>
      <description><![CDATA[As highway transportation network systems are highly vulnerable to severe earthquakes, it is desirable to consider directionality effect of earthquake ground motion in assessing the seismic damageability of highway bridges. However, it is very difficult to rigorously incorporate the multidimensional effect of ground motions in the design and response analysis of bridges. The current paper presents a procedure in which bridges can be designed to ensure safety under single or a pair of independent orthogonal ground motions traveling horizontally with an arbitrary direction to bridge axis. This procedure uses nonlinear time history analysis and expresses the prediction of bridge seismic damageability in the form of fragility curves. Fragility curves are gaining practical recognition through, for example, their use in HAZUS for seismic risk assessment. Change in fragility characteristics of bridges for different direction of ground motion propagation directly indicates the effect of directionality on bridge seismic response. Result showed that ground motion directionality can alter bridge seismic damageability substantially and hence, plays an important role in the estimation of maximum seismic demand. In this context, the result here may add directionality as another factor to be considered in HAZUS to adjust fragility curves for standard bridges. The word directionality used here is different from “directivity” used in seismology to mean a specific characteristic of seismic fault movement.]]></description>
      <pubDate>Wed, 16 Nov 2011 14:51:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1122138</guid>
    </item>
    <item>
      <title>Seismic Performance Goals and Probabilistic Assessment of Expansion Joints for Highway Bridges</title>
      <link>https://trid.trb.org/View/1122125</link>
      <description><![CDATA[Seismic specifications acknowledge the need for post-event functionality for essential and critical bridges, either explicitly or implicitly, in terms of structural seismic performance. A move towards performance based design and assessment of bridges and their components necessitates the ability to evaluate the likelihood of achieving a given set of performance goals within a level of confidence. However, these strategic performance goals for seismic expansion joints in bridges have yet to be adequately defined and little research has considered the influence and performance of seismic expansion joints on the post-event functionality of bridge systems. Uncertainties in the ground shaking, seismic demand, and capacity must be characterized in order to assess the potential for damage to the joints themselves and their effect on the failure potential for the overall bridge system. Additionally, the states of damage evaluated should have links to anticipated functionality of the bridge in order to investigate how joint selection ultimately affects bridge functionality. This paper proposes a framework for reliability assessment of seismic expansion joints through the development of seismic fragility curves. Damage due to pounding in non-seismic joints and engineered seismic expansion joints are compared probabilistically. The curves can be used to evaluate the reliability of different expansion joints, as well as the influence of the joints on the bridge performance as a whole including anticipated allowable traffic carrying capacity.]]></description>
      <pubDate>Wed, 16 Nov 2011 14:51:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1122125</guid>
    </item>
    <item>
      <title>Seismic Risk Assessment of the Transportation Network of Charleston, South Carolina</title>
      <link>https://trid.trb.org/View/1120883</link>
      <description><![CDATA[The functionality of the transportation network following an earthquake event is critical for post-earthquake response and long-term recovery. The likely performance of a transportation network can be evaluated through a detailed seismic risk assessment. This paper presents an assessment of the seismic risk to the transportation network in Charleston, South Carolina and the surrounding counties to support emergency planning efforts and for prioritizing retrofit. This study includes an inventory analysis of the approximately 375 bridges in the Charleston area and convolution of the seismic hazard with fragility curves analytically derived for classes of bridges common to this part of the country. Damage-functionality relationships and replacement cost estimates based region-specific data are used to obtain economic loss and functionality estimates. Using state-of-the-art tools, the distribution of potential bridge damage and functionality is evaluated for several scenario events in order to aid in the identification of emergency routes and assess areas for investment in retrofit. Initial estimates of economic losses are assessed and preliminary recommendations for emergency routes and prioritized retrofitting are presented.]]></description>
      <pubDate>Wed, 16 Nov 2011 14:51:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1120883</guid>
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