TRANSVERSE DISTRIBUTION FACTORS FOR HORIZONTALLY CURVED BRIDGES UNDER THE EFFECT OF PERMIT VEHICLES
Open Access
- Author:
- Yang, Bowen
- Graduate Program:
- Civil Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 14, 2018
- Committee Members:
- Jeffrey A Laman, Thesis Advisor/Co-Advisor
Ali M Memari, Committee Member
Konstantinos Papakonstantinou, Committee Member - Keywords:
- live load distribution factor
curved bridge
warping and bending
permit vehicle
steel I-girder bridge - Abstract:
- Permit vehicles with non-standard gage are increasingly used to carry heavy and oversized cargos. Currently, approximate methods and evaluation of the transverse, live load, girder distribution factor (GDF) for horizontally curved, steel, I-girder bridges subjected to permit vehicles are lacking. Therefore, the effect of permit vehicles on GDFs for curved bridges needs to be determined to allow rapid and efficient evaluation for issue of permits. Four permit vehicles obtained from a Pennsylvania Department of Transportation (PennDOT) database and twenty-seven curved bridges from Kim (2007) are analyzed with CSiBridge® to conduct the parametric study. The present study evaluates the influence of key parameters (radius, span length, girder spacing, and gage) on moment GDFs, determines if GDFs for permit vehicles can be accurately predicted by modifying AASHTO approximate moment GDF equations, and establishes an approximate GDFs for the outermost girder. Two approximate moment GDF models from Kim (2007) are utilized: (1) The single GDF model (SGM); and (2) the combined GDF model (CGM) to calculate GDF for curved bridges subjected to permit vehicles. A linear regression analysis is conducted to determine the relationship between AASHTO approximate GDFs and GDFs for curved bridges subjected to permit vehicles to develop a proposed, approximate GDF equation for curved girder bridges. Based on the numerical results from FEM, SGM and CGM, the present study demonstrates that GDFs for curved bridges cannot be accurately predicted by AASHTO approximate GDFs. The present study develops a new approximate GDF equation to predict moment distribution in curved bridges with respect to radius, span length, and vehicle gage. The numerical iv analysis results demonstrate that span length and radius have larger effects on GDFs than girder spacing and vehicle gage. A goodness-of-fit method combined with the linear regression analysis propose two developed approximate GDF equations (SGM and CGM equations). Both two developed approximate GDF equations are demonstrated to accurately predict GDFs for curved bridges compared to FEM results and provide slightly larger results compared to FEM results. GDFs for HL-93 are also calculated and be demonstrated to have larger results than GDFs for the evaluated permit vehicles.