Behavior of Horizontally Curved Multi-Spans Continuous Composite Bridges under AASHTO LRFD Loading

Abstract

The purpose of this paper is to study the effects of bridge curvature and spans continuity on the lateral distribution of the flexural and warping longitudinal stresses among girders in a horizontally curved continuous composite bridge under AASTHO LRFD loading. To achieve this goal, numerical analysis is conducted by using finite element program CSI Bridge. The bridge prototype adopted comprises a continuous three equal spans bridge with 120m total length. Bridges with different AASHTO live load cases and curvature ratios (L/R) are investigated. The study has revealed that the bridge curvature is the most influential factor that affect lateral stress distribution among girders. Generally, as curvature ratio increases, warping stresses increased, and thus stress distribution among girders became vastly non-uniform and extremely deviate from straight bridge behavior. Moreover, as (L/R) ratio increased the stress share for the outermost girders increased and for the innermost girders decreased and for high curvature ratio moment and stress reversal occur at mid span for the interior girders. The study shows that girders maximum stress values occurred for the case of a bridge loaded with AASHTO lane load and truck load on the exterior lane only.