Download or read book Development of Live Load Distribution Factor Equations for Girder Bridges written by Nakin Suksawang and published by . This book was released on 2006 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of New Distribution Factor Equations of Live Load Moment and Shear for Steel Open box Girder Bridges written by Lei Zheng and published by . This book was released on 2008 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simplified Live Load Distribution Factor Equations written by BridgeTech, Inc and published by Transportation Research Board. This book was released on 2007 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains the findings of research performed to develop recommended Load and Resistance Factor Design (LRFD) live load distribution factor design equations for shear and moment. The report details the development of equations that are simpler to apply and have a wider range of applicability than current methods. The appendices are not published in this report, but are available online at http://www.trb.org/news/blurb_detail.asp?id=7938.
Download or read book Single Lane Live Load Distribution Factor for Decked Precast prestressed Concrete Girder Bridges written by John Zhongguo and published by . This book was released on 2005 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The live load distribution factor (DF) equations provided by AASHTO-LRFD for the decked precast/prestressed concrete (DPPC) girder bridge system do not differentiate between a single or multilane loaded condition. This practice results in a single lane load rating penalty for DPPC girder bridges. The objective of this project is to determine DF equations which accurately predict the distribution factor of the DPPC girder bridge system when it is only subjected to single lane loading. Eight DPPC girder bridges were instrumented. Each bridge was loaded with a single load vehicle to simulate the single lane loaded condition. The experimental data was used to calibrate 3D FE models and 2D grillage models of the DPPC girder bridge system. The calibrated models were used to conduct a parametric study of the DPPC girder bridge system subjected to a single lane loaded condition. Two sets of new equations that describe the single lane loaded distribution factor for both shear and moment forces of these bridges are proposed and compared with AASHTOLRFD DF equations.
Download or read book Live load Distribution on Glued laminated Timber Girder Bridges written by and published by . This book was released on 2011 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased use of timber bridges in the U.S. transportation system has required additional research to improve the current design methodology of these bridges. For this reason, the U.S. Forest Service, Forest Products Laboratory (FPL), and the Federal Highway Administration have supported several research programs to attain the objective listed above. This report is a result of a study sponsored by the FPL, with the objective of determining how highway truckloads are distributed to girders of a glued-laminated timber bridge. The American Association of State Highway and Transportation Official (AASHTO) load and resistance factor design (LRFD) Bridge Design Specification provides live-load distribution provisions for glued-laminated girder timber bridges that were used in previous AASHTO Specifications. The AASHTO live-load distribution provisions were reviewed in this report. Field-test results were used to review the current AASHTO LRFD glued-laminated timber girder bridge-design specifications and to validate analytical results obtained by finite-element analyses. With the validated analytical models, parametric studies were performed to determine the worst-case live-load distribution factors that can be used to calculate the design moment and shear for glued-laminated timber girders. Simplified live-load distribution equations that can be used to determine these distribution factors were developed and are provided in this report. These equations take into account how load is distributed to the bridge girders, considering the effects of span length, girder spacing, and clear width of the bridge.
Download or read book Live Load Distribution on Longitudinal Glued laminated Timber Girder Bridges written by and published by . This book was released on 2011 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased use of timber bridges in the U.S. transportation system has required additional research to improve the current design methodology of these bridges. For this reason, the U.S. Forest Service, Forest Products Laboratory (FPL), and the Federal Highway Administration have supported several research programs to attain the objective listed above. This report is a result of a study sponsored by the FPL, with the objective of determining how highway truckloads are distributed to girders of a glued-laminated timber bridge. The American Association of State Highway and Transportation Official (AASHTO) load and resistance factor design (LRFD) Bridge Design Specification provides live-load distribution provisions for glued-laminated girder timber bridges that were used in previous AASHTO Specifications. The AASHTO live-load distribution provisions were reviewed in this report. Field-test results were used to review the current AASHTO LRFD glued-laminated timber girder bridge-design specifications and to validate analytical results obtained by finite-element analyses. With the validated analytical models, parametric studies were performed to determine the worst-case live-load distribution factors that can be used to calculate the design moment and shear for glued-laminated timber girders. Simplified live-load distribution equations that can be used to determine these distribution factors were developed and are provided in this report. These equations take into account how load is distributed to the bridge girders, considering the effects of span length, girder spacing, and clear width of the bridge.
Download or read book Single Lane Live Load Distribution Factor for Decked Precast written by Jason Langdon Millam and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Alaska Department of Transportation (AKDOT) uses the decked precast, prestressed concrete bulb-tee girder for most of its bridge construction. The live load distribution factor (DF) equations provided by the American Association of State Highway and Transportation Officials (AASHTO) for the decked bulb-tee girder system do not differentiate between a single or multilane loaded condition. This practice results in a single lane load rating penalty for decked bulb-tee girder bridges. The research objective of this thesis is to determine DF simplified equations that accurately predict the distribution factor of the decked bulb-tee girder system when it is only subjected to single lane loading. Eight decked bulb-tee bridges were instrumented. Each bridge was loaded with a single load vehicle to simulate the single lane loaded condition. The experimental data were used to calibrate grillage models of the decked bulb-tee girder system. The calibrated grillage models were used to conduct a parametric study of the bulb-tee girder system subjected to single lane loaded condition. Eight new simplified equations that describe the single lane loaded distribution factor for both shear and moment forces of these bridges are developed in this thesis"--Leaf iii.
Download or read book Development of a Bridge Construction Live Load Analysis Guide written by and published by . This book was released on 2011 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of LRFD Specifications for Horizontally Curved Steel Girder Bridges written by J. M. Kulicki and published by Transportation Research Board National Research. This book was released on 2006 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains the findings of research performed to develop design specifications for horizontally curved steel girder bridges.
Download or read book Live Load Distribution in Multi cell Box Girder Bridges and Its Comparison with the AASHTO LRFD Bridge Design Specifications written by Shin-Tai Song and published by . This book was released on 2001 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Design Specifications and Commentary for Horizontally Curved Concrete Box girder Bridges written by Nutt, Redfield, and Valentine and published by Transportation Research Board. This book was released on 2008 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides specifications, commentary, and examples for the design of horizontally curved concrete box-girder highway bridges. The report details the development of the design procedures. Recommended Load and Resistance Factor Design (LRFD) specifications and design examples illustrating the application of the design methods and specifications are included in appendixes (available on the TRB website at http://trb.org/news/blurb_detail.asp?id=9596).
Download or read book Simplified Load Distribution Factor for Use in LRFD Design written by Elisa D. Sotelino and published by . This book was released on 2004-09-01 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The “S-over” equation for the load distribution factor (LDF) was first introduced in the 1930s in the AASHTO Standard. Finite element studies, however, have shown it to be unsafe in some cases and too conservative in others. In this study, a new simplified equation that is based on the AASHTO LRFD formula and does not require an iterative procedure is developed. The new simplified equation produces LDF values that are always conservative when compared to those obtained from the finite element analyses and are generally greater than the LDF obtained using AASHTO LRFD specification. Therefore, the simplified equation provides a simple yet safe specification for LDF calculation. This study also investigates the effects of secondary elements and bridge deck cracking on the LDF of bridges. The AASHTO LRFD LDF equation was developed based on elastic finite element analysis considering only primary members, i.e., the effects of secondary elements such as lateral bracing and parapets were not considered. Meanwhile, many bridges have been identified as having significant cracking in the concrete deck. Even though deck cracking is a well-known phenomenon, the significance of pre-existing cracks on the live load distribution has not yet been assessed in the literature. First, secondary elements such as diaphragms and parapet were modeled using the finite element method, and the calculated load distribution factors were compared with the code-specified values. Second, the effects of typical deck cracking and crack types that have a major effect on load distribution were identified through a number of nonlinear finite element analyses. Transverse cracking was found to not significantly influence the transverse distribution of moment. Finally, for one of the selected bridges, both concrete cracking and secondary elements are considered to invesitigate their combined effect on lateral load distribution. The increased LDF due to deck cracking is offset by the contributions from the secondary elements. The result is that the proposed simplified equation is conservative and is recommended for determination of LDF.
Download or read book Live Load Distribution Factor Comparison for a Curved Steel Box Girder Bridge written by Cory E. Schultz and published by . This book was released on 2010 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Design Guideline for Phase Construction of Steel Girder Bridges written by Atorod Azizinamini and published by . This book was released on 2003 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Live Load Distribution in One and Two cell Box girder Bridges written by Paul Chung and published by . This book was released on 2008 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the focus is to investigate the load distribution factors (LDF) for moment and shear of cast-in-place one and two-cell box girders for bridges with typical dimensions. The computed LDFs will be compared with those computed from AASHTO. It will be demonstrated that the current AASHTO LDFs are not adequate for the design of CIP one- and two-cell box girders. A modified ste of equations is proposed and further verified through parametric studies carried out for two-and three-span bridges.
Download or read book Live Load Distribution Factors in Two girder Bridge Systems Using Precast Trapezoidal U girders written by Salahudin Mensah and published by . This book was released on 2010 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Live Load Distribution Factors for Exterior Girders in Steel I girder Bridges written by Gregory K. Michaelson and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
