Title:
Development of Live Load Distribution Factor Equation for Concrete Multicell Box-Girder Bridges under Vehicle Loading
Author(s):
Won Choi, Iman Mohseni, Jongsup Park and Junsuk Kang
Publication:
IJCSM
Volume:
13
Issue:
Appears on pages(s):
Keywords:
finite element modelling, distribution factor, truck, box bridges
DOI:
10.1186/s40069-019-0336-1
Date:
3/31/2019
Abstract:
The evaluation and design of concrete bridges in large part depend on the transverse distribution characteristics
of the live load carried and the service level. The live load distribution for continuous concrete multicell box-girder
bridges varies according to bridge configuration, so when designing such bridges, it is important to determine the
maximum negative stress at the piers, the midspan positive (tensile) stress and the deflection of the bridge when
subjected to live loads. This paper reports an extensive parametric study to determine the maximum stress, deflection,
and moment distribution factors for two span multicell box-girder bridges based on a finite element analysis of 120
representative numerical model bridges. Bridge parameters were selected to extend the parameters and ranges of
current live load distribution factors defined by AASHTO LRFD specifications. The results indicate that the span length,
number of boxes, and the number of lanes all significantly affect the positive (tensile) and the negative (compression)
stress distribution factors. A set of equations proposed to describe the behavior of such bridges under AASHTO LRFD
live loads yielded results that agreed closely with the numerically derived results for the stress and deflection distribution factors.