Load Factors for Evaluating Permit Vehicles


Book Description

In recent years, requests to move heavy vehicles across bridges have risen dramatically. Highway agencies find it necessary to calculate safety margins under loads significantly above legal levels. For some regions of the U.S., permits have effectively raised the legal vehicle weight. Reliability analysis is used in this study to model live load uncertainties (using bridge weigh-in-motion data) and other dead load and resistance variables. Target safety indices are introduced by calibration with existing bridge rating and posting practices. Simulation of the expected maximum load effects of permit vehicles plus alongside vehicles has been carried out for both frequent permits, for different traffic classifications including volume and traffic enforcement levels, and single passage permits. Load factors are calibrated to achieve the target safety indices for different simple and continuous spans. A checking format for permit vehicles is proposed for possible inclusion in a bridge evaluation code. For the covering abstract of the Conference see IRRD Abstract No. 807839.







A Comparison of AASHTO Bridge Load Rating Methods


Book Description

TRB’s National Cooperative Highway Research Program (NCHRP) Report 700: A Comparison of AASHTO Bridge Load Rating Methods documents an analysis of 1,500 bridges that represent various material types and configurations using AASHTOWareTM Virtis® to compare the load factor rating to load and resistance factor rating for both moment and shear induced by design vehicles, American Association of State Highway and Transportation Officials (AASHTO) legal loads, and eight additional permit/legal vehicles.







An Introduction to Bridge Load Rating Procedures


Book Description

Introductory technical guidance for civil engineers and others interested in bridge load rating procedures. Here is what is discussed: 1. INTRODUCTION 2. PURPOSE 3. LOAD RATING REQUIREMENTS 4. QUALIFICATIONS AND RESPONSIBILITIES 5. QUALITY CONTROL AND QUALITY ASSURANCE 6. BRIDGE LOAD RATING PROCEDURE 7. DATA COLLECTION 8. MATERIAL PROPERTIES 9. LOAD EFFECTS—VEHICULAR BRIDGES 10. LOAD EFFECTS—PEDESTRIAN BRIDGES 11. COMPONENT CAPACITY 12. LOAD RATING 13. LOAD POSTING 14. MATERIAL STRENGTH TESTING 15. RATINGS FROM NONDESTRUCTIVE LOAD TESTING 16. ASSIGNED LOAD RATINGS 17. LOAD RATINGS BASED ON FIELD EVALUATION AND ENGINEERING JUDGMENT 18. LOAD RATING DOCUMENTATION.




Bridge Design and Evaluation


Book Description

A succinct, real-world approach to complete bridge system design and evaluation Load and Resistance Factor Design (LRFD) and Load and Resistance Factor Rating (LRFR) are design and evaluation methods that have replaced or offered alternatives to other traditional methods as the new standards for designing and load-rating U.S. highway bridges. Bridge Design and Evaluation covers complete bridge systems (substructure and superstructure) in one succinct, manageable package. It presents real-world bridge examples demonstrating both their design and evaluation using LRFD and LRFR. Designed for a 3- to 4-credit undergraduate or graduate-level course, it presents the fundamentals of the topic without expanding needlessly into advanced or specialized topics. Important features include: Exclusive focus on LRFD and LRFR Hundreds of photographs and figures of real bridges to connect the theoretical with the practical Design and evaluation examples from real bridges including actual bridge plans and drawings and design methodologies Numerous exercise problems Specific design for a 3- to 4-credit course at the undergraduate or graduate level The only bridge engineering textbook to cover the important topics of bridge evaluation and rating Bridge Design and Evaluation is the most up-to-date and inclusive introduction available for students in civil engineering specializing in structural and transportation engineering.




Bridge Rating Practices and Policies for Overweight Vehicles


Book Description

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 359: Bridge Rating Practices and Policies for Overweight Vehicles explores overweight vehicle permit processes. The report includes information on state and provincial bridge rating systems, bridge evaluation practices, and permit policies as they relate to overweight and oversize vehicles. The report is designed to help in the understanding of the reasons for nonuniform permitting practices. The report reviews specifications, software types, treatment of nonstandard configurations, and allowance for in-place dead loads; processes of permit review; and personnel assigned to permit review.







The Manual for Bridge Evaluation


Book Description




Bridge Engineering Handbook, Second Edition


Book Description

Over 140 experts, 14 countries, and 89 chapters are represented in the second edition of the Bridge Engineering Handbook. This extensive collection highlights bridge engineering specimens from around the world, contains detailed information on bridge engineering, and thoroughly explains the concepts and practical applications surrounding the subject. Published in five books: Fundamentals, Superstructure Design, Substructure Design, Seismic Design, and Construction and Maintenance, this new edition provides numerous worked-out examples that give readers step-by-step design procedures, includes contributions by leading experts from around the world in their respective areas of bridge engineering, contains 26 completely new chapters, and updates most other chapters. It offers design concepts, specifications, and practice, as well as the various types of bridges. The text includes over 2,500 tables, charts, illustrations, and photos. The book covers new, innovative and traditional methods and practices; explores rehabilitation, retrofit, and maintenance; and examines seismic design and building materials. The fifth book, Construction and Maintenance contains 19 chapters, and covers the practical issues of bridge structures. What’s New in the Second Edition: Includes nine new chapters: Steel Bridge Fabrication, Cable-Supported Bridge Construction, Accelerated Bridge Construction, Bridge Management Using Pontis and Improved Concepts, Bridge Maintenance, Bridge Health Monitoring, Nondestructive Evaluation Methods for Bridge Elements, Life-Cycle Performance Analysis and Optimization, and Bridge Construction Methods Rewrites the Bridge Construction Inspection chapter and retitles it as: Bridge Construction Supervision and Inspection Expands and rewrites the Maintenance Inspection and Rating chapter into three chapters: Bridge Inspection, Steel Bridge Evaluation and Rating, and Concrete Bridge Evaluation and Rating; and the Strengthening and Rehabilitation chapter into two chapters: Rehabilitation and Strengthening of Highway Bridge Superstructures, and Rehabilitation and Strengthening of Orthotropic Steel Bridge Decks This text is an ideal reference for practicing bridge engineers and consultants (design, construction, maintenance), and can also be used as a reference for students in bridge engineering courses.