Single Lane Live Load Distribution Factor for Decked Precast/prestressed Concrete Girder Bridges


Book Description

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.




Single Lane Live Load Distribution Factor for Decked Precast


Book Description

"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.







Three Dimensional Finite Element Analysis of Decked Precast, Prestressed Concrete Girder Bridges


Book Description

"The speed of construction has become the key issue for bridges. This is especially true in cold regions like Alaska, where you face a very short summer season. The speed of construction can be expedited by connections. As there are advantages in connections there are also disadvantages. One of the primary advantages of the connectors is that it makes the load transfer mechanism very efficient. However everything comes for a price. Maintenance of connections is very difficult. Routine inspections are to be made to ensure proper functioning of the system. This becomes a very important factor in Alaska where extreme winter conditions exists. Another issue is that the current connector design is based on an empirical approach. A rational design method is needed. In this study an effort has been made to find the presence of ISD on the live load distribution factor for single lane loading. Using ABAQUS CAE, 3D finite element (FE) models have been developed and analyzed with different parameters. By varying the parameters, different distribution factors corresponding to the reaction, strains (flexure and shear) as well as the forces originating from the connectors are evaluated and compared. This paper provides a basis for future connector design"--Leave iv.




Simplified Live Load Distribution Factor Equations


Book Description

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.




Connection of Simple-span Precast Concrete Girders for Continuity


Book Description

Introduction and Research Approach -- Findings -- Interpretation, Appraisal, and Application -- Interpretation, Appraisal, and Application -- References -- Appendixes.




Bridge Analysis Simplified


Book Description







Highway Bridge Superstructure Engineering


Book Description

A How-To Guide for Bridge Engineers and DesignersHighway Bridge Superstructure Engineering: LRFD Approaches to Design and Analysis provides a detailed discussion of traditional structural design perspectives, and serves as a state-of-the-art resource on the latest design and analysis of highway bridge superstructures. This book is applicable to hig




The Manual for Bridge Evaluation


Book Description