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Load Rating Strategies For Bridges With Limited Or Missing As Built Information
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Book Synopsis Load Rating Strategies for Bridges with Limited Or Missing As-built Information by : Devin K. Harris
Download or read book Load Rating Strategies for Bridges with Limited Or Missing As-built Information written by Devin K. Harris and published by . This book was released on 2020 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Load Rating of Bridges and Culverts with Missing Or Incomplete As-built Information by : Harry W. Shenton
Download or read book Load Rating of Bridges and Culverts with Missing Or Incomplete As-built Information written by Harry W. Shenton and published by . This book was released on 2022 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Load ratings are used in part to allocate federal funding to agencies and to plan for repairing, replacing, and rehabilitating bridges. Therefore, load ratings can affect the movement of goods throughout a region and are vitally important to the continued safe and efficient operation of the highway system. The TRB National Cooperative Highway Research Program's NCHRP Synthesis 571: Load Rating of Bridges and Culverts with Missing or Incomplete As-Built Information gathers and synthesizes information on the methods that states currently use to perform load ratings of bridges and culverts with missing or incomplete as-built information and, in doing so, to establish the current state of practice.
Book Synopsis Dynamics of Civil Structures, Volume 2 by : Juan Caicedo
Download or read book Dynamics of Civil Structures, Volume 2 written by Juan Caicedo and published by Springer. This book was released on 2017-06-01 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Civil Structures, Volume 2: Proceedings of the 35th IMAC, A Conference and Exposition on Structural Dynamics, 2017, the second volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of the Dynamics of Civil Structures, including papers on: Modal Parameter Identification Dynamic Testing of Civil Structures Control of Human Induced Vibrations of Civil Structures Model Updating Damage Identification in Civil Infrastructure Bridge Dynamics Experimental Techniques for Civil Structures Hybrid Simulation of Civil Structures Vibration Control of Civil Structures System Identification of Civil Structures
Book Synopsis Bridge Load Rating by : Rafael Armendariz
Download or read book Bridge Load Rating written by Rafael Armendariz and published by . This book was released on 2018-08-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The inspection and evaluation of bridges in Indiana is critical to ensure their safety to better serve the citizens of the state. Part of this evaluation includes bridge load rating. Bridge load rating, which is a measure of the safe load capacity of the bridge, is a logical process that is typically conducted by utilizing critical information that is available on the bridge plans. For existing, poorly-documented bridges, however, the load rating process becomes challenging to adequately complete because of the missing bridge information. Currently, the Indiana Department of Transportation (INDOT) does not have a prescribed methodology for such bridges. In an effort to improve Indiana load rating practices INDOT commissioned this study to develop a general procedure for load rating bridges without plans. The general procedure was developed and it was concluded that it requires four critical parts. These parts are bridge characterization, bridge database, field survey and inspection, and bridge load rating. The proposed procedure was then evaluated on two bridges in Indiana that do not have plans as a proof of concept. As a result, it was concluded that load rating of bridges without plans can be successfully completed using the general procedure. A flowchart describing the general procedure was created to make the load rating process more user-friendly. Additional flowcharts that summarize the general procedure for different type of bridges were also provided.
Book Synopsis Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings by : Mary Beth Deisz Hueste
Download or read book Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings written by Mary Beth Deisz Hueste and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the 2016 National Bridge Inventory data, the state of Texas houses over 2100 bridges posted at load levels below the legal limit. While load postings are generally a management issue, there can be commerce, traffic, and emergency egress issues. For this reason, removing postings is always of interest. Posted structures come in all shapes and sizes, were 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 were developed to reduce uncertainty in load rating procedures in a safe and appropriate manner to potentially increase or remove the load postings of typical steel and concrete bridges. The first phase of the project focused on the detailed review and synthesis of the relevant literature, analysis of the load-posted bridge inventory in Texas, and conducting basic load rating analysis of selected typical bridge types to identify and examine controlling limit states and areas of opportunities that could lead to an increase or removal of load posting. This Volume 1 research report fully documents the state-of-the-practice and state-of-the-art on load rating of existing bridges, the review and synthesis of the bridge characteristics of load-posted bridges in Texas, and the basic load rating for selected representative bridges to identify the controlling limit states that likely lead to an increased operating load for these bridges.
Book Synopsis Review of Load Rating and Posting Procedures and Requirements by : Mark Bowen
Download or read book Review of Load Rating and Posting Procedures and Requirements written by Mark Bowen and published by . This book was released on 2014-12-31 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: All states are required to load rate and post bridges in order to comply with federal standards. Load ratings are performed in order to determine the safe live load capacity of a bridge, considering the existing conditions of the bridge. Based on the load ratings, the bridge is evaluated for load posting or strengthening. The Indiana Department of Transportation (INDOT) was notified that their practice for load rating and posting did not satisfy 23 CFR 650.313. The purpose of this study was to summarize and compare load rating and posting procedures used in other states and to provide recommendations and information necessary to modify the load rating and posting procedures in INDOT's Bridge Inspection Manual (Part 3: Load Rating) in order to satisfy 23 CFR 650.313.In order to understand how load rating and posting is performed in other states, department of transportation (DOT) manuals were examined, questionnaires were sent to states, and additional states of interest were surveyed. The American Association of State Highway and Transportation Officials (AASHTO) The Manual for Bridge Evaluation, Second Edition, which is the current specification for load rating and posting bridges was reviewed, as well as older AASHTO bridge evaluation manuals. Based on this information, revisions were proposed to the INDOT Bridge Inspection Manual (Part 3: Load Rating) in order to eliminate current deficiencies.
Book Synopsis Diagnostic and Proof Load Tests on Bridges by : Fikret Necati Catbas
Download or read book Diagnostic and Proof Load Tests on Bridges written by Fikret Necati Catbas and published by Frontiers Media SA. This book was released on 2020-12-11 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Book Synopsis Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings by : Mary Beth Deisz Hueste
Download or read book Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings written by Mary Beth Deisz Hueste and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings by : Mary Beth Deisz Hueste
Download or read book Development of a Strategy to Address Load-posted Bridges Through Reduction in Uncertainty in Load Ratings written by Mary Beth Deisz Hueste and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 they post load restrictions if the capacity of a bridge does not meet the maximum load effect based on 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, are built in different eras and environments, and exhibit vastly different structural behaviors. Thus, there is no clear-cut single solution for addressing the possibility of removing postings. In this study, strategies were developed to reduce uncertainty in load rating procedures in a safe and appropriate manner to potentially increase or remove the load postings of typical steel and concrete bridges. The Volume 1 report (Hueste et al. 2019a) documented findings that included 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. This Volume 2 report documents 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. The load testing of the selected load-posted bridges, along with model updating and calibration based on the field measurements, is used to determine refined load ratings to compare with the basic load ratings. The results are reviewed with respect to the implications and opportunities for load rating these bridges and similar bridge structures to potentially increase the posted loads or remove the load restrictions.
Book Synopsis Estimating the Load Rating of Reinforced Concrete Bridges Without Plans by : Edgardo Ruiz
Download or read book Estimating the Load Rating of Reinforced Concrete Bridges Without Plans written by Edgardo Ruiz and published by . This book was released on 2020 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are over 250,000 reinforced concrete bridges in the U.S. many of which do not have a load rating on record nor the plans required to perform the calculations. The U.S. Army owns and maintains hundreds of these bridges throughout the U.S. This dissertation describes the development of multiple regression models to estimate the load rating of reinforced concrete bridges. An exploratory data analysis of the 2017 NBI data was performed for the selection of a representative data sample. The data was found to have multiple errors and required significant processing in order to extract a reliable sample for modeling. After processing, a data sample of 31,112 bridges remained, providing sufficient sample for model training and testing. A six-variable model (Model A) was determined to provide the best performance while maintaining a desired low level of complexity. The model was tested by comparing the percentage of cases that fell within its 95% prediction interval, which resulted in 94.9% of the real values falling within the prediction interval. Given the concerns that arose of the quality of the 2017 NBI data during its exploration, as built-drawings from 50 slab bridges throughout the U.S. were collected. With these drawings a new data sample was generated by calculating the load rating of each bridge. Availability of the as-built drawings provided the opportunity to investigate other variables not available in the 2017 NBI, most notably the slab thickness. This data sample was significantly smaller than the previous one, therefore a repeated 10-fold cross-validation approach was taken to evaluate model performance. It was determined that a five-variable model (Model B) provided the best trade-off between complexity and performance. Model B performed significantly better than Model A due to the inclusion of the slab thickness variable. The models presented in this dissertation provide a valuable tool for reinforced concrete bridge owners tasked with the assigning a load rating when no structural plans are available helping.
Book Synopsis A Procedure for Load Rating Reinforced Concrete Slab Bridges Without Plans by : Alain Michael Cuaron
Download or read book A Procedure for Load Rating Reinforced Concrete Slab Bridges Without Plans written by Alain Michael Cuaron and published by . This book was released on 2016 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridges without plans are a problem in the state of New Mexico since standard bridge load rating techniques cannot be used due to the lack of design plans and documentation that contains the required information such as the amount and location of the reinforcement. A research project was conducted for the New Mexico Department of Transportation (NMDOT) to provide an effective method to load rate reinforced concrete slab bridges without plans using both structural analysis and non-destructive experimental techniques. This thesis presents the evaluation of two simple-span and two continuous-span reinforced concrete slab bridges. Bridge 8486 is a simple-span reinforced concrete slab bridge located in Albuquerque, NM. The bridge was built in 1984. According to the most current bridge inspection report for the bridge, the bridge had a satisfactory condition rating for the deck and superstructure and a good condition rating for the substructure. The bottom reinforcement layout was determined using a Hilti Ferroscan along with an AASHTO-based required steel area estimate while the material properties were determined based on the age of the bridge. The final load ratings from an AASHTOWare BrR analysis show that Bridge 8486 is capable of carrying an HS-20 vehicle safely. Bridge 8282 is a simple-span reinforced concrete slab that was built in 1976. The bridge is located in Albuquerque, NM. The bridge has a satisfactory condition rating for the deck and superstructure while the substructure was given a fair condition rating based on the most current bridge inspection report. The bottom reinforcement layout and material properties were estimated similarly to Bridge 8486. The final BrR load ratings show that the bridge has a load carrying capacity that can safely carry an HS-20 vehicle. Bridge 8827 is a three-span continuous reinforced concrete slab bridge. The bridge was built in 1991 in Albuquerque, NM. The deck, superstructure and substructure were given a fair condition rating in the most current bridge inspection report. Like Bridge 8486 and Bridge 8282, the bottom reinforcement was estimated using a Hilti Ferroscan, however, the scanner did not provide enough data to estimate the top reinforcement layout. Therefore, the top reinforcement layout was estimated using a combination of AASHTO, a top to bottom steel area ratio assumption (i.e., steel area for the top of the slab above the pier is 10% larger than the bottom steel area at midspan), and the Hilti Ferroscan results. Based on the final BrR load ratings, the bridge can carry an HS-20 vehicle safely. Bridge 7489 is a two-span continuous reinforced concrete slab bridge. The bridge was built in 1964 in Albuquerque, NM. The bridge had satisfactory condition ratings for the deck, superstructure, and substructure. The bottom and top reinforcement layout were estimated using the Hilti Ferroscan along with the required steel area estimation following AASHTO. The bridge load rating from BrR showed that the bridge could carry an HS-20 vehicle.
Book Synopsis Load Rating Highway Bridges by : Lubin Gao
Download or read book Load Rating Highway Bridges written by Lubin Gao and published by . This book was released on 2013-05-30 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: LOAD RATING HIGHWAY BRIDGES In accordance with Load and Resistance Factor Rating Method First Edition The first comprehensive text introducing the background theory along with the practical procedure of load rating highway bridges with the state-of-the-art Load and Resistance Factor Rating (LRFR) method. With its simplicity and complete contents on this subject, this is an indispensable text for both students and practicing engineers. The safety of bridges is essential to the traveling public. To ensure that bridges in our highway system function safely and serve properly, engineers need to inspect and assess the live load carrying capacity of the bridges. Based on the results of inspection and evaluation, decisions are made on load restriction, repair, retrofit or replacement. Load rating, one of the critical tasks in this decision-making process, uses either an analytical method or non-destructive load testing to determine the live load carrying capacity of a bridge. This is a book solely concentrated on bridge load rating by using analytical load rating methods, with a focus on the LRFR method. The primary purpose of this book is to provide the basic concept of load rating highway bridges in terms of the LRFR method. The target readers are practicing engineers who want to acquire fundamental knowledge of the LRFR method. Bearing that in mind, the author attempts to strike a balance between theory and how-to. Engineers who are conducting or will perform load ratings of bridges can use this text as a reference in supplement to the AASHTO Manual for Bridge Evaluation (MBE). This book can also serve as a textbook or supplemental material for a senior level undergraduate or graduate course in bridge design and load rating. This text is divided into three major sections. The first section contains a brief introduction to bridge load rating (Chapter 1) and fundamentals of structural failure and structural reliability theory (Chapter 2). After completing this section, re
Book Synopsis AASHTO Guide Manual for Bridge Element Inspection by :
Download or read book AASHTO Guide Manual for Bridge Element Inspection written by and published by AASHTO. This book was released on 2011 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Guide Manual for Bridge Element Inspection builds on the element-level condition assessment methods developed in the AASHTO Guide for Commonly Recognized Structural Elements, which it replaces. Improvements have been made to fully capture the condition of the elements by reconfiguring the element language to utilize multiple distress paths within the defined condition states. The multi-path distress language provides the means to fully incorporate all possible defects within the overall condition assessment of the element. The overall condition of an element can be utilized in this aggregate form, or broken down into specific defects present as desired by the agency for Bridge Management System (BMS) use. The Bridge Element Inspection Manual provides a comprehensive set of bridge elements that is designed to be flexible in nature to satisfy the needs of all agencies. The complete set of elements capture the components necessary for an agency to manage all aspects of the bridge inventory utilizing the full capability of a BMS -- Publisher's website.
Book Synopsis Engineering for Structural Stability in Bridge Construction by : Federal Highway Federal Highway Administration
Download or read book Engineering for Structural Stability in Bridge Construction written by Federal Highway Federal Highway Administration and published by . This book was released on 2020-07-19 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual is intended to serve as a reference. It will provide technical information which will enable Manual users to perform the following activities:Describe typical erection practices for girder bridge superstructures and recognize critical construction stagesDiscuss typical practices for evaluating structural stability of girder bridge superstructures during early stages of erection and throughout bridge constructionExplain the basic concepts of stability and why it is important in bridge erection* Explain common techniques for performing advanced stability analysis along with their advantages and limitationsDescribe how differing construction sequences effect superstructure stabilityBe able to select appropriate loads, load combinations, and load factors for use in analyzing superstructure components during constructionBe able to analyze bridge members at various stages of erection* Develop erection plans that are safe and economical, and know what information is required and should be a part of those plansDescribe the differences between local, member and global (system) stability
Book Synopsis Investigating Available State-of-the-art Technology for Determining Needed Information for Bridge Rating Strategies by : Afshin Karshenas
Download or read book Investigating Available State-of-the-art Technology for Determining Needed Information for Bridge Rating Strategies written by Afshin Karshenas and published by . This book was released on 2020 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report, nondestructive test (NDT) methods are evaluated in the context of providing input parameters to perform bridge load rating calculations for different bridge types. Relevant NDT methods are identified based on diverse technologies including mechanical impact, acoustic, electromagnetic, electrical and chemical, nuclear, and miscellaneous methods. The required parameters for successful bridge load rating of concrete precast slab (COPCSS), concrete slab (COSLAB), concrete prestress channel (COPSCH), prestressed girder bridges, and steel bridges are identified and the available NDT methods to provide these parameters are presented. These parameters are categorized in three basic groups that consist of as-built geometric parameters, as-built strength parameters, and as-inspected strength parameters. All the available NDT techniques that can be used to obtain each parameter have been presented. Finally, the NDT methods are rated by cost, ease of use, and reliability of data using a three-level rating system and the most cost effective, feasible, and reliable methods have been recommended.
Book Synopsis Evaluating Bridge Performance: Load Rating Bridges Without Plans and Experimental Displacement Influence Lines by : Jun Huang
Download or read book Evaluating Bridge Performance: Load Rating Bridges Without Plans and Experimental Displacement Influence Lines written by Jun Huang and published by . This book was released on 2007 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the best alternatives for bridges which need accurate load rating, is through field testing. Presented in this dissertation are two studies on evaluating the performance of bridges based on the results of a diagnostic load test. The first topic is focused on load rating bridges without plans using the results of a diagnostic test. The second topic is focused on utilizing measured displacements from a field test to evaluate the bridge performance.
Book Synopsis Performance Characteristics of In-Service Bridges for Enhancing Load Ratings: Leveraging Refined Analysis Methods by : Devin K. Harris
Download or read book Performance Characteristics of In-Service Bridges for Enhancing Load Ratings: Leveraging Refined Analysis Methods written by Devin K. Harris and published by . This book was released on 2021 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
