Using Dynamic Characteristics Of Bridges For Practical Analysis With Distribution Factors

Abstract

The common and practical practice in bridge girder analysis for load rating is based on simplified approach which incorporates distribution factors to accommodate for the contribution of all structural elements in the 3D configuration. The distribution factor formulations for shear and moment in design codes include span length, beam spacing, beam stiffness and slab thickness. In this study, the writers are exploring whether experimental quantities which are mainly the dynamic characteristics can be used to more precisely determine the distribution factors. As a result, this study aims to investigate moment and shear distribution factors of simple span T-beam bridges by using frequency ω , flexibility f ii and skew θ . In this study, first 40 Finite Element Models that are created by using solid elements, will be analyzed and frequency and flexibility values will be collected. Second, the moment and shear values are collected for all models under HL-20 truck load. Third, multiple regression analysis will be conducted to generate an appropriate equation which includes frequency, flexibility and skew to find the distribution factors. Lastly; frequency, flexibility and skew from experimental data will be used to demonstrate the concept on a real bridge. © 2009 Society for Experimental Mechanics Inc