Performance Characteristics Of In Service Bridges For Enhancing Load Ratings Leveraging Refined Analysis Methods PDF Download
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Author | : Devin K. Harris |
Publisher | : |
Total Pages | : 0 |
Release | : 2021 |
Genre | : Bridges |
ISBN | : |
Download Performance Characteristics of In-Service Bridges for Enhancing Load Ratings: Leveraging Refined Analysis Methods Book in PDF, ePub and Kindle
Bridge load rating assesses the safe live load carrying capacity of an existing or newly designed structure. In addition to load rating with previously defined standard load rating vehicles, the Federal Highway Administration issued additional guidance to states related to rating requirements for all the bridges with respect to specialized hauling vehicles and emergency vehicles that must be met by the end of 2022. It is recognized that the load effects (bending moment and shear) produced by these vehicle types on certain bridge types and spans might be greater than those caused by the previous rating vehicles. Therefore, a number of bridges within VDOT's inventory may require posting when rated with these specialized vehicles. The goal of this study was to assess the likelihood of an increase in load rating factors through refined analysis methods for the bridge classes potentially vulnerable to load ratings under consideration of the new federal regulations and when using conventional, simplified equations for load distribution factors. In particular, the study focused on the evaluation of live load distribution factors for girder bridges and effective widths for distributing live loads in slab bridges through refined analysis. Three bridge classes (simple span steel girder bridges, reinforced concrete T-beam bridges, and concrete slab bridges) were selected for this refined analysis. Girder bridges were modeled using the plate-with-an-eccentric-beam analysis approach, while plate elements were used to model slab bridges within the LARSA 4D software package. The selected modeling approaches were validated through the simulation of the bridge structures with available field-testing results from the literature. A total of 71 in-service bridges belonging to the three selected bridge classes were then modeled and analyzed to compute the load distribution factors for girder bridges or effective widths for slab bridges, and the results were compared with those obtained from the code-specified equations. Using the data obtained from these numerical simulations, a series of multi-parameter linear regression models were developed to predict the percent change in distribution factor and effective width, respectively, for girder and slab bridges with different geometrical characteristics if a refined method analysis is implemented. The regression models were limited to four parameters such that the results from regression models could be presented in table format. The developed tables should be used as screening tools to provide guidance on the use of refined methods of analysis to improve the load ratings of bridges vulnerable to posting from previously existing load rating classifications as well as the recently introduced vehicles. Should VDOT use refined methods of analysis, there is good potential that the agency can avoid posting a substantial portion of its inventory, saving resources for more critical needs while safely keeping Virginia's bridges open for commerce and the traveling public
Author | : Devin K. Harris |
Publisher | : |
Total Pages | : 0 |
Release | : 2020 |
Genre | : Bridges |
ISBN | : |
Download Load Rating Strategies for Bridges With Limited Or Missing As-Built Information Book in PDF, ePub and Kindle
Load rating is the process of determining the safe load-carrying capacity of a bridge; however, when plans and details are insufficient to determine the overall capacity of the structure, alternative methods must be used to infer what the live load capacity is. Two viable methods allowed by the AASHTO Manual for Bridge Evaluation are the commonly used but subjective engineering judgement and the experimentally based proof testing. However, these methods suffer from limitations. Engineering judgement typically is not based on physical phenomena and creates a degree of risk in unconservative estimates or unnecessarily restricts traffic and commerce if estimates are overly conservative. On the contrary, proof testing can cause damage during testing, tends to be expensive, and cannot be extrapolated to future performance. Thus, the objective of this study was to develop rational engineering approaches for load rating structures within the Virginia Department of Transportation (VDOT) inventory for which limited as-built information is available. The initial phase of the investigation focused on categorizing the VDOT inventory to determine the types of structures that are likely to be missing information necessary for an analytical load rating, which were identified to be short span reinforced concrete slab or T-beam designs. Subsequent phases emphasized two main approaches to load rating: (i) structural identification frameworks based on finite element model updating; and (ii) leveraged vibration response characterization. Both approaches emphasized estimating unknown characteristics of these types of structures for use in a traditional analytical load rating. These unknown parameters include modulus of elasticity and strength of concrete as well as cross-sectional area of steel reinforcement. These estimates can ultimately be used to provide a rational estimate of load ratings. All approaches were evaluated on two slab and two T-beam structures in varying condition states, which had sufficient plans available, but were treated as having varying degrees of unknown details. The results illustrated that the finite element model updating method generated load ratings that were within 0% to -17% of the load ratings developed according to conventional calculations, with negative differences indicating lower rating factor estimates; and the vibration-based simplified method led to results with a percent difference ranging from 16% to -16%. It was also shown that instrumenting bridges with a limited number of sensors is sufficient for successful implementation of the developed methods. The results from the study have been synthesized into recommendations for VDOT to perform load ratings of structures with insufficient plans or information, with the goal of minimizing the degree and complexity of experimental measurement as well as simplifying the tools for performing the analyses of these structures as much as feasible.
Author | : Mary Beth Deisz Hueste |
Publisher | : |
Total Pages | : 0 |
Release | : 2022 |
Genre | : Bridges |
ISBN | : |
Download Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings Book in PDF, ePub and Kindle
Maintaining the functionality of the transportation infrastructure depends on the successful management of aging bridge assets. Departments of Transportation rely on the load rating process to evaluate the sufficiency of the bridge structures in their state, and post load restrictions if the capacity of a bridge does not meet the maximum load effect based on the current legal loads. Removing load postings is always of interest because there can be commerce, traffic, and emergency egress issues due to rerouting of vehicles. Posted structures come in various shapes and sizes, built in different eras and environments, and exhibit vastly different structural behaviors. As such, there is no clear-cut single solution for addressing the possibility of removing postings. In this study, strategies have been developed to reduce uncertainty in load rating procedure in a safe and appropriate manner to potentially increase or remove the load postings of typical steel and concrete bridges. The Volume 1 Report documents findings including a review of the state-of-the-practice and state-of-the-art for load rating existing bridges, a review and synthesis of the bridge characteristics of load posted bridges in Texas, and the basic load rating analysis conducted for selected representative bridges to identify the controlling limit states. The Volume 2 Report provides details of further study for typical bridges including refined analysis for more accurate prediction of load distribution, load testing, model updating and calibration, and refined load rating analysis. This Volume 3 Report provides specific recommendations for refined load rating analysis for the four selected bridges types, and provides detailed refined load rating examples for each bridge type. The effect of each refinement on the revised load ratings is evaluated, and the implications for potentially increasing the posted loads or removal of load posting are discussed.
Author | : Nripendra P. Rana |
Publisher | : Springer Nature |
Total Pages | : 337 |
Release | : 2019-11-11 |
Genre | : Business & Economics |
ISBN | : 3030243745 |
Download Digital and Social Media Marketing Book in PDF, ePub and Kindle
This book examines issues and implications of digital and social media marketing for emerging markets. These markets necessitate substantial adaptations of developed theories and approaches employed in the Western world. The book investigates problems specific to emerging markets, while identifying new theoretical constructs and practical applications of digital marketing. It addresses topics such as electronic word of mouth (eWOM), demographic differences in digital marketing, mobile marketing, search engine advertising, among others. A radical increase in both temporal and geographical reach is empowering consumers to exert influence on brands, products, and services. Information and Communication Technologies (ICTs) and digital media are having a significant impact on the way people communicate and fulfil their socio-economic, emotional and material needs. These technologies are also being harnessed by businesses for various purposes including distribution and selling of goods, retailing of consumer services, customer relationship management, and influencing consumer behaviour by employing digital marketing practices. This book considers this, as it examines the practice and research related to digital and social media marketing.
Author | : Anol Bhattacherjee |
Publisher | : CreateSpace |
Total Pages | : 156 |
Release | : 2012-04-01 |
Genre | : Science |
ISBN | : 9781475146127 |
Download Social Science Research Book in PDF, ePub and Kindle
This book is designed to introduce doctoral and graduate students to the process of conducting scientific research in the social sciences, business, education, public health, and related disciplines. It is a one-stop, comprehensive, and compact source for foundational concepts in behavioral research, and can serve as a stand-alone text or as a supplement to research readings in any doctoral seminar or research methods class. This book is currently used as a research text at universities on six continents and will shortly be available in nine different languages.
Author | : F. C. Campbell |
Publisher | : ASM International |
Total Pages | : 699 |
Release | : 2012-01-01 |
Genre | : Technology & Engineering |
ISBN | : 1615039767 |
Download Fatigue and Fracture Book in PDF, ePub and Kindle
"This book emphasizes the physical and practical aspects of fatigue and fracture. It covers mechanical properties of materials, differences between ductile and brittle fractures, fracture mechanics, the basics of fatigue, structural joints, high temperature failures, wear, environmentally-induced failures, and steps in the failure analysis process."--publishers website.
Author | : |
Publisher | : |
Total Pages | : 854 |
Release | : 1965 |
Genre | : Occupations |
ISBN | : |
Download Dictionary of Occupational Titles Book in PDF, ePub and Kindle
Supplement to 3d ed. called Selected characteristics of occupations (physical demands, working conditions, training time) issued by Bureau of Employment Security.
Author | : United States Employment Service |
Publisher | : |
Total Pages | : 846 |
Release | : 1965 |
Genre | : Occupations |
ISBN | : |
Download Dictionary of Occupational Titles: Definitions of titles Book in PDF, ePub and Kindle
Author | : American Association of State Highway and Transportation Officials. Subcommittee on Bridges and Structures |
Publisher | : AASHTO |
Total Pages | : 41 |
Release | : 2011 |
Genre | : Bridges |
ISBN | : 1560514965 |
Download The Manual for Bridge Evaluation Book in PDF, ePub and Kindle
Author | : Nelson Lim |
Publisher | : |
Total Pages | : 0 |
Release | : 2019-11-30 |
Genre | : Business & Economics |
ISBN | : 9781977403421 |
Download Leveraging Big Data Analytics to Improve Military Recruiting Book in PDF, ePub and Kindle
The authors identified current, desired, and prospective data-enabled practices that the U.S. Department of Defense and the services might be able to deploy in their outreach and recruiting processes.