Download or read book Reliability based Condition Assessment of Existing Highway Bridges written by Naiyu Wang and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Condition assessment and safety verification of existing bridges and decisions as to whether bridge posting is required are addressed through analysis, load testing, or a combination of methods. Bridge rating through structural analysis is by far the most common procedure for rating existing bridges. The American Association of State Highway and Transportation Officials (AASHTO) Manual for Bridge Evaluation (MBE), First Edition permits bridge capacity ratings to be determined through allowable stress rating (ASR), load factor rating (LFR) or load and resistance factor rating (LRFR); the latter method is keyed to the AASHTO LRFD Bridge Design Specifications, which is reliability-based and has been required for the design of new bridges built with federal findings since October, 2007. A survey of current bridge rating practices in the United States has revealed that these three methods may lead to different ratings and posting limits for the same bridge, a situation that carries serious implications with regard to the safety of the public and the economic well-being of communities that may be affected by bridge postings or closures. To address this issue, a research program has been conducted with the overall objective of providing recommendations for improving the process by which the condition of existing bridge structures is assessed. This research required a coordinated program of load testing and finite element analysis of selected bridges in the State of Georgia to gain perspectives on the behavior of older bridges under various load conditions. Structural system reliability assessments of these bridges were conducted and bridge fragilities were developed for purposes of comparison with component reliability benchmarks for new bridges. A reliability-based bridge rating framework was developed, along with a series of recommended improvements to the current bridge rating methods, which facilitate the incorporation of various in situ conditions of existing bridges into the bridge rating process at both component and system levels. This framework permits bridge ratings to be conducted at three levels of increasing complexity to achieve the performance objectives, expressed in the terms of reliability, that are embedded in the LRFR option of the AASHTO Manual of Bridge Evaluation. This research was sponsored by the Georgia Department of Transportation, and has led to a set of Recommended Guidelines for Condition Assessment and Evaluation of Existing Bridges in Georgia.

Download or read book Integration of Structural Health Monitoring Information to Reliability Based Condition Assessment and Life Cycle Costing of Bridges written by Bhasker Dubey and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to Transportation Association of Canada (TAC), the rough estimate of number of bridges in Canada is 80,000 with the replacement value of $35 billion. A large number of bridges will need replacement during 2005 to 2015 which will result in 50% annual increase in replacement cost. Recent alarming incidents of the Laval De la Concorde Overpass collapse (2006), Canada and the I-35W Mississippi River bridge collapse (2007), USA show the gravity of the situation. One of the main factors responsible for this situation is the present available techniques of the bridge condition monitoring and rehabilitation are not able to cope up with the drastic deterioration and ageing of the bridges. The widely employed method for bridge inspection is visual inspection, and it lacks the reliability-based assessment of bridge and its components. The instrumentation of the bridge with Structural Health Monitoring (SHM) systems and assessment of the bridge condition and behaviour based on the information obtained from SHM systems is one of the promising solutions of the present problem. The main focus of the current research is to integrate SHM data with traditional information (e.g. visual inspection), develop a reliability based structural condition index using the updated information on a structures operational performance, and assessing the value of information for SHM in regard to the overall lifecycle cost of a structure. This study develops a methodology for a reliability based assessment of the bridge components using SHM system information, and information updating by fusing SHM data with traditional information for precise evaluation of expected life cycle cost. The methods developed herein have been demonstrated through a case study based on an existing bridge namely, the Crowchild Bridge in Calgary, Alberta. A finite element model of the bridge has been developed and validated against the field data. This validated model has been used to simulate the static load test on the bridge, deterioration in the bridge and to study the bridge response under the different loading conditions. The artificial neural network (ANN) technique has been used for the diagnosis of the SHM data, and then the reliability index of the bridge deck has been calculated using the Monte Carlo Simulation technique. A method for updating the bridge deck repair strategy is introduced based on the reliability index calculation. The maintenance and rehabilitation strategy is updated based on the hypothetical results. The results of updated strategy are compared with un-updated one using the Bayesian Theorem. The expected life cycle cost is evaluated considering the capital cost, maintenance and rehabilitation cost, user cost, and failure cost. Capital cost is treated as deterministic while maintenance and rehabilitation cost, and user cost are considered probabilistic. Each individual cost and then total cost is calculated per m 2 . The value of information is also discussed.

Download or read book Reliability based assessment of highway bridges written by Parag C. Das and published by . This book was released on 1999 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reliability and Safety of Cable Supported Bridges written by Naiwei Lu and published by CRC Press. This book was released on 2021-06-17 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge design and construction technologies have experienced remarkable developments in recent decades, and numerous long-span bridges have been built or are under construction all over the world. Cable-supported bridges, including cable-stayed bridges and suspension bridges, are the main type of these long-span bridges, and are widely used in highways crossing gorges, rivers, and gulfs, due to their superior structural mechanical properties and beautiful appearance. However, cable-supported bridges suffer from harsh environmental effects and complex loading conditions, such as heavier traffic loads, strong winds, corrosion effects, and other natural disasters. Therefore, the lifetime safety evaluation of these long-span bridges considering the rigorous service environments is an essential task. Features: Presents a comprehensive explanation of system reliability evaluation for all aspects of cable-supported bridges. Includes a comprehensive presentation of the application of system reliability theory in bridge design, safety control, and operational management. Addresses fatigue reliability, dynamic reliability and seismic reliability assessment of bridges. Presents a complete investigation and case study in each chapter, allowing readers to understand the applicability for real-world scenarios. Reliability and Safety of Cable-Supported Bridges provides a comprehensive application and guidelines for system reliability techniques in cable-supported bridges. Serving as a practical educational resource for both undergraduate and graduate level students, practicing engineers, and researchers, it also intends to provide an intuitive appreciation for probability theory, statistical methods, and reliability analysis methods.

Download or read book Leveraging Technologies for Condition Assessment of Multi Girder Highway Bridges written by Shi Ye and published by . This book was released on 2020 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: A majority of US highway bridges were constructed in the mid-20th century. Today, bridge owners have to consider increases in traffic demands and also face concerns related to sustainability, resilience and livability which were virtually unknown in the 1950s. In this context, transportation stakeholders face increasingly complex decisions for repair, retrofit or renewal of their assets. Legislature demands data-driven decisions based on quantitative and reliable bridge condition and performance evaluation. Different technology tools that can provide objective condition evaluations have become available but given the inertia in the practice of bridge engineering and a lack of understanding the challenges to their reliable applications, their use remain limited. Consequently, management decisions are still primarily made without leveraging objective measurement data and without a mechanistic understanding of bridge behavior and performance. To explore the current state-of-the-art in performance and condition evaluation of constructed systems by leveraging technology, a 30-year old highway bridge in New Jersey, exhibiting multiple complex performance deficiencies, was transformed into a field laboratory. To identify the root causes of performance concerns, Visual Inspection, Operational Monitoring, Forced Excitation Testing, Controlled Load Testing, Non-destructive Probes, Long-term Monitoring and Finite Element Modeling and Parameter Identification were conducted within a Structural Identification framework. The results showed that root causes of some performance deficiencies of the test bridge could be identified only through the application of field measurements and analyses integrated by following a scientific approach - such as Structural Identification, especially for deficiencies related to unexpected dynamic amplifications and the long-term effects of vibrations. Controlled Load Testing was especially useful in demonstrating the location and impacts of damage although such an approach can only be considered for the most critical cases due to its high cost and disruption to operations. Operational monitoring was shown as a sufficient and cheaper alternative for structural identification permitting the development of a lesser resolution digital twin of the bridge, which was critical in identifying the root causes of its deficiencies and formulating meaningful interventions.

Download or read book Structural Reliability and Time Dependent Reliability written by Cao Wang and published by Springer Nature. This book was released on 2020-12-15 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides structural reliability and design students with fundamental knowledge in structural reliability, as well as an overview of the latest developments in the field of reliability engineering. It addresses the mathematical formulation of analytical tools for structural reliability assessment. This book offers an accessible introduction to structural reliability assessment and a solid foundation for problem-solving. It introduces the topic and background, before dealing with probability models for random variables. It then explores simulation techniques for single random variables, random vectors consisting of different variables, and stochastic processes. The book addresses analytical approaches for structural reliability assessment, including the reliability models for a single structure and those for multiple structures, as well as discussing the approaches for structural time-dependent reliability assessment in the presence of discrete and continuous load processes. This book delivers a timely and pedagogical textbook, including over 170 worked-through examples, detailed solutions, and analytical tools, making it of interest to a wide range of graduate students, researchers, and practitioners in the field of reliability engineering.

Download or read book Nondestructive Condition Assessment of a Posted Bridge written by and published by . This book was released on 1997 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are about five hundred steel-truss highway bridges in Ohio, as well as many thousands in the nation, which are more than seventy-five years old. Preservation of aged historic steel-truss bridges first requires a consideration of public safety issues. Bridges with certain structural attributes and materials are well established as having non desirable failure modes, which make them public safety hazards. These should be removed from service with the highest possible priority. If non-technical issues such as historic significance and functional adequacy are favorable, the question then becomes whether a given bridge can be preserved within the available financial and technical resources of the responsible government agency.

Download or read book Proposed Guideline for Reliability based Bridge Inspection Practices written by Glenn A. Washer and published by . This book was released on 2014 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 782: Proposed Guideline for Reliability-Based Bridge Inspection Practices presents a proposed guideline for reliability-based bridge inspection practices and provides two case studies of the application of the proposed guideline. The guideline describes a methodology to develop a risk-based approach for determining the bridge inspection interval according to the requirements in Moving Ahead for Progress in the 21st Century Act (MAP-21)."--Publisher description.

Download or read book Bridge Optimization written by Yun Lai Zhou and published by BoD – Books on Demand. This book was released on 2020-02-05 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a collection of several applications for condition monitoring and damage identification in bridge structures. Bridge structural condition monitoring is essential since it can provide early warning of potential defects in bridges, which may induce catastrophic accidents and result in huge economic loss. Such bridge condition monitoring relies on sensing techniques, especially advanced sensing techniques that can provide detailed information on bridge structures. Additionally, postprocessing systems can interpret the captured data and warn of any potential faults. This book will give students a thorough understanding of bridge condition monitoring.

Download or read book Safety Reliability Risk and Life Cycle Performance of Structures and Infrastructures written by George Deodatis and published by CRC Press. This book was released on 2014-02-10 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety, Reliability, Risk and Life-Cycle Performance of Structures and Infrastructures contains the plenary lectures and papers presented at the 11th International Conference on STRUCTURAL SAFETY AND RELIABILITY (ICOSSAR2013, New York, NY, USA, 16-20 June 2013), and covers major aspects of safety, reliability, risk and life-cycle performance of str

Download or read book Multi Scale Reliability and Serviceability Assessment of In Service Long Span Bridges written by Naiwei Lu and published by Momentum Press. This book was released on 2018-05-08 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the development in global economic and transportation engineering, the traffic loads on brides have been growing steadily, which become potential safety hazards for existing bridges. In particular, long-span suspension bridges support heavy traffic volumes and simultaneous truck loads on the bridge deck, and thus the safety and serviceability of the bridge deserves investigation. In this book, a multiscale reliability method is presented for the safety assessment of long-span bridges. The multiscale failure condition of stiffness girders is the first-passage criteria for the large-scale model and the fatigue damage criteria for the small-scale model. It is the objective of this book to provide a more in-depth understanding of the vehicle-bridge interaction from the random vibration perspective. This book is suitable for adoption as a text book or a reference book in an advanced structural reliability analysis course. Furthermore, this book also provides a theoretical foundation for better understanding of the safety assessment, operation management, maintenance and reinforcement for long-span bridges and motivates further research and development for more advanced reliability and serviceability assessment techniques for long-span bridges.

Download or read book Condition Assessment and Maintenance of Bridges by Reliability Concept written by Mitao Ohga and published by LAP Lambert Academic Publishing. This book was released on 2011-03 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge infrastructures of most countries in the world are currently getting older and resource allocations are often limited. Hence, many researchers have pointed out that there is an urgent need to study their condition assessment to minimize bridge failures and reduce maintenance costs. They further express that present visual and deterministic assessment methods are not precise enough to count for many uncertainties of bridges. This book, therefore, introduces a condition assessment and maintenance strategy of bridges and bridge systems using reliability concept which is a branch of classical probability theory. The book includes an introduction to the reliability concept, reliability formulations of maintenance problems and case studies. This study should help bridge engineers and experts working on bridge maintenance and further academics and graduate students who are interested in bridge engineering and probabilistic approach.

Download or read book Bridge Management written by M. J. Ryall and published by Springer. This book was released on 2013-12-14 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume consists of papers presented at the First International Conference on Bridge Management, held at The University of Surrey, Guildford, UK, from 28-30 March 1990.

Download or read book Time variant Reliability of Reinforced Concrete Bridges Under Environmental Attack written by Michael Patrick Enright and published by . This book was released on 1999 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the United States, life-cycle cost analysis is gradually becoming a requirement for bridge design, inspection, repair and replacement decisions. Bridges are designed to function over long periods of time, but can experience changes in both resistance and applied loads which are time-variant. Current reliability-based codes for buildings and bridges are largely limited to individual structural component checks, and do not consider the potential damaged states of a structural system and the ability of the damaged system to continue to carry loads. Furthermore, current codes do not entail the prediction of the failure time of deteriorating structural systems under time-varying loads. Although the need for the application of time-variant system reliability methods to bridge life-cycle cost prediction is becoming increasingly recognized in the U.S., most reliability studies on reinforced concrete bridges do not consider the time dependence of the resistance or post-failure behavior of bridge elements. In this study, the time-variant system reliability of reinforced concrete highway girder bridges subjected to time-dependent load and resistance is investigated. The approach, which is based on combining adaptive importance sampling and numerical integration, is suitable for predicting the reliability of reinforced concrete bridges under environmental stressors such as corrosion. The effects of corrosion initiation time and rate on time-variant strength of reinforced concrete beams are illustrated using Monte Carlo simulation. An existing reinforced concrete T-beam bridge located near Pueblo, Colorado, is investigated. A comparison of reliability estimates for several system models is given, including the influence of correlation among initial girder strengths. Post-failure behavior of components and load redistribution effects are also considered. The influence of inspection updating on time-variant system failure probability is illustrated using Bayesian-based numerical integration. Optimal inspection/repair strategies are included which are based on minimum lifecycle cost within prescribed reliability constraints. The results can be used as a guide for the selection of system models for bridge reliability analysis, identification of critical girders in a bridge system, and for the development of optimal reliability-based maintenance strategies for reinforced concrete highway bridges.

Download or read book Bridge Collapse Frequencies versus Failure Probabilities written by Dirk Proske and published by Springer. This book was released on 2018-02-22 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph provides a comparative study between failure probabilities and collapse frequencies in structural bridge engineering. The author presents techniques to resolve and extend the limitations of both parameters, taking also into account the time dependency of both parameters. The book includes available data and case studies and thus presents patterns to identify potential weaknesses and challenges in bridge maintenance. The target audience primarily comprises practicing engineers in the field of bridge engineering, but the book may also be beneficial for academic researchers alike.

Download or read book Maintenance Monitoring Safety Risk and Resilience of Bridges and Bridge Networks written by Tulio Nogueira Bittencourt and published by CRC Press. This book was released on 2016-11-17 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maintenance, Monitoring, Safety, Risk and Resilience of Bridges and Bridge Networks contains the lectures and papers presented at the Eighth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2016), held in Foz do Iguaçu, Paraná, Brazil, 26-30 June, 2016. This volume consists of a book of extended abstracts and a DVD containing the full papers of 369 contributions presented at IABMAS 2016, including the T.Y. Lin Lecture, eight Keynote Lectures, and 360 technical papers from 38 countries. The contributions deal with the state-of-the-art as well as emerging concepts and innovative applications related to all main aspects of bridge maintenance, safety, management, resilience and sustainability. Major topics covered include: advanced materials, ageing of bridges, assessment and evaluation, bridge codes, bridge diagnostics, bridge management systems, composites, damage identification, design for durability, deterioration modeling, earthquake and accidental loadings, emerging technologies, fatigue, field testing, financial planning, health monitoring, high performance materials, inspection, life-cycle performance and cost, load models, maintenance strategies, non-destructive testing, optimization strategies, prediction of future traffic demands, rehabilitation, reliability and risk management, repair, replacement, residual service life, resilience, robustness, safety and serviceability, service life prediction, strengthening, structural integrity, and sustainability. This volume provides both an up-to-date overview of the field of bridge engineering as well as significant contributions to the process of making more rational decisions concerning bridge maintenance, safety, serviceability, resilience, sustainability, monitoring, risk-based management, and life-cycle performance using traditional and emerging technologies for the purpose of enhancing the welfare of society. It will serve as a valuable reference to all involved with bridge structure and infrastructure systems, including students, researchers and engineers from all areas of bridge engineering.

Download or read book Safety and performance concept Reliability assessment of concrete structures written by fib Fédération internationale du béton and published by FIB - Féd. Int. du Béton. This book was released on 2018-08-01 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete structures have been built for more than 100 years. At first, reinforced concrete was used for buildings and bridges, even for those with large spans. Lack of methods for structural analysis led to conservative and reliable design. Application of prestressed concrete started in the 40s and strongly developed in the 60s. The spans of bridges and other structures like halls, industrial structures, stands, etc. grew significantly larger. At that time, the knowledge of material behaviour, durability and overall structural performance was substantially less developed than it is today. In many countries statically determined systems with a fragile behavior were designed for cast in situ as well as precast structures. Lack of redundancy resulted in a low level of robustness in structural systems. In addition, the technical level of individual technologies (e.g. grouting of prestressed cables) was lower than it is today. The number of concrete structures, including prestressed ones, is extremely high. Over time and with increased loading, the necessity of maintaining safety and performance parameters is impossible without careful maintenance, smaller interventions, strengthening and even larger reconstructions. Although some claim that unsatisfactory structures should be replaced by new ones, it is often impossible, as authorities, in general, have only limited resources. Most structures have to remain in service, probably even longer than initially expected. In order to keep the existing concrete structures in an acceptable condition, the development of methods for monitoring, inspection and assessment, structural identification, nonlinear analysis, life cycle evaluation and safety and prediction of the future behaviour, etc. is necessary. The scatter of individual input parameters must be considered as a whole. This requires probabilistic approaches to individual partial problems and to the overall analysis. The members of the fib Task Group 2.8 “Safety and performance concepts” wrote, on the basis of the actual knowledge and experience, a comprehensive document that provides crucial knowledge for existing structures, which is also applicable to new structures. This guide to good practice is divided into 10 basic chapters dealing with individual issues that are critical for activities associated with preferably existing concrete structures. Bulletin 86 starts with the specification of the performance-based requirements during the entire lifecycle. The risk issues are described in chapter two. An extensive part is devoted to structural reliability, including practical engineering approaches and reliability assessment of existing structures. Safety concepts for design consider the lifetime of structures and summarise safety formats from simple partial safety factors to develop approaches suitable for application in sophisticated, probabilistic, non-linear analyses. Testing for design and the determination of design values from the tests is an extremely important issue. This is especially true for the evaluation of existing structures. Inspection and monitoring of existing structures are essential for maintenance, for the prediction of remaining service life and for the planning of interventions. Chapter nine presents probabilistically-based models for material degradation processes. Finally, case studies are presented in chapter ten. The results of the concrete structures monitoring as well as their application for assessment and prediction of their future behaviour are shown. The risk analysis of highway bridges was based on extensive monitoring and numerical evaluation programs. Case studies perfectly illustrate the application of the methods presented in the Bulletin. The information provided in this guide is very useful for practitioners and scientists. It provides the reader with general procedures, from the specification of requirements, monitoring, assessment to the prediction of the structures’ lifecycles. However, one must have a sufficiently large amount of experimental and other data (e.g. construction experience) in order to use these methods correctly. This data finally allows for a statistical evaluation. As it is shown in case studies, extensive monitoring programs are necessary. The publication of this guide and other documents developed within the fib will hopefully help convince the authorities responsible for safe and fluent traffic on bridges and other structures that the costs spent in monitoring are first rather small, and second, they will repay in the form of a serious assessment providing necessary information for decision about maintenance and future of important structures.