Download or read book Effect of Oversized and Overweight Trucks on Live Load Distribution in Girder Bridges written by Muna Tabatabai and published by . This book was released on 1999 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Term Effects of Super Heavy Weight Vehicles on Bridges written by Scott M. Wood and published by Purdue University Press. This book was released on 2007-04-01 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: A permit truck which exceeds the predefined limit of 108 kips is defined as a superload in Indiana. This study was conducted to examine the long-term effects of superload trucks on the performance of typical slab-on-girder bridges and to assess the likelihood of causing immediate damage. Typical steel and prestressed concrete slab-on-girder type bridges were analyzed using both beam line analysis and detailed finite element models. Furthermore, one prestressed concrete bridge and one steel bridge were instrumented using more than 50 sensors each. Strains and deflections were measured during a live load test, and each bridge was monitored for more than six months. Capacities of the investigated bridges were calculated and compared with the demands generated by various groupings of typical superload trucks. Analysis of the steel and prestressed concrete bridges demonstrated that typical superload trucks up to a gross vehicle weight of 500 kips are not expected to cause any damage or impair the long term performance of the investigated bridges. Serviceability limit states of the prestressed concrete bridges controlled the rating, and the bridges had adequate strength to accommodate all superloads included in the database. However, strength limit states controlled the rating of steel bridges. Long term monitoring of a continuous and a simple span bridge indicated that strains comparable to those of a 366-kip superload truck can be generated by regular truck traffic. The field measurements also demonstrated that the in-service behavior was different than the design assumptions. Furthermore, the AASHTO girder distribution factor equation was found to be conservative for the investigated bridges. Use of a more accurate method such as FEA or the spring analogy method is recommended for the evaluation of bridges traversed by very heavy superload trucks.
Download or read book Bulb T Girder Bridge Barrier Effect on Live Load Distribution written by Tal Stricker and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Bulb-T girder bridges are composed of precast, prestressed concrete beams with a reinforced concrete slab. Typically, the slab extends transversely beyond the exterior beam, and there is a traffic barrier on the edge. The bridges are designed for dead and live loads and prestressing effects. For the live loads, the transverse distribution of moment and shear load effects to interior and exterior girders is determined by using equations in the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications. These equations give the designer a factor, which is then multiplied by the moment or shear load effect determined by a line analysis. The equations assume that barriers are not present. The Florida Department of Transportation (FDOT) Structures Research Lab has made field measurements on a Bulb-T bridge, both before and after the barriers were placed, due to a truck loaded with blocks. For this project, this data was analyzed to determine the barrier's effect on the live load distribution. The results of this project may be used to determine if load ratings can be improved by consideration of the barrier effect, which can be done as a Posting Avoidance (Exception) technique.
Download or read book Overload Permit Procedures written by James S. Noel and published by . This book was released on 1992 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical study of H15 bridges in Texas has resulted in an improved procedure for issuing overweight truck permits. Single and multiple axle limits, specifically to protest pavements rather than bridges, are assumed. The weight restrictions limit any (and all) axle groups as a function of the gage and tire contact widths. The restrictions were derived to assure that the maximum stress in any bridge member never exceeds the operating level. Only one vehicle is allowed on the bridge at a time but it is assumed to be traveling at a speed such that the full impact allowance is generated.
Download or read book Live Load Spectra for Girder Bridges written by Hani Hamad Nassif and published by . This book was released on 1993 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fifth International Bridge Engineering Conference written by and published by . This book was released on 2000 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Papers presented at the Fifth International Bridge Engineering Conference, April 3-5, 2000, Tampa, Florida.
Download or read book Transportation Research Record written by and published by . This book was released on 2000 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 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 Simplified Method for Determining Live Load Distribution Factors for Overweight Vehicles with Non standard Axle Configurations written by Brian L. Goodrich and published by . This book was released on 1999 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Influence of Load Reduction in Multi lane Bridges written by Imad Youssef Naddaf and published by . This book was released on 1998 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the behavior of multi-lane steel girder bridues subject to reduced loading using the finite element method The most critical behavior of a highway bridge is thought to result from a fully loaded bridge (live load on all lanes) It is a common practice to apply reduction factors for bridges with more than two lanes These reduction factors are to account for the probability that all lanes be loaded at the same time Therefore, this study will investigate these reduction factors by analyzing three-lane and four-lane steel girder bridges fully loaded, two out of three-lanes, and three out of four-lanes loaded bridges The behavior of these bridges will be investigated by studying the effect of load removal on the lateral wheel load distribution factor The results of this study w ill be used to assess the empirical reduction factors currentK employed by the American .Association of State Highway and Transportation Officials (AASHTO) "Standard Specifications for Highway Bridges (19%) ".--This study will consider critical parameters identified in previous research such as simple (one-span), and continuous (two-span), girder spacing, span length, three-lane bridges and four-lane bridges The finite element method is proposed to analyze the steel girder bridges by using the structural analysis program SAP90 The research will focus on evaluating the maximum lateral wheel load distribution to the steel girders subject to the full (all lanes are loaded) and reduced (bridge partially loaded) design live loading Bridges will be loaded using AASHTO design taicks positioned in the longitudinal direction in order to produce either the maximum positive and/or the maximum negative bending moments.
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 Effects of Increased Live Load on Typical Highway Bridge Girder Sizes written by Farzad Yazdani and published by . This book was released on 1981 with total page 212 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:
