Analysis on Live Load Distribution Factors of Widened Hollow Core Slab Bridges

Abstract

There are some studies on live load distribution factors(LLDF) of hollow core slab bridges which mainly consider the influence of connecting method and rigidity, while the effects of span length and skew angle have not been fully involved. Influenced by the trend of road and river, the hollow core slab bridges are often skewed with rivers. So it is essential to study the span length and skew angle effects in bridge widening. Based on a highway widening project, some representative hollow core slab bridges are selected for widening analysis. Theoretical method and finite element method are used to analysis the LLDF of slab bridges before and after widening. Finite element method(FEM) can give high precision in LLDF calculating. The influences of span length, connecting stiffness and skew angle are studied. The result indicates that no matter before or after widening the LLDF become smaller with the increase of span length. After widening, the LLDF of the half slabs near to the widening seam reduce obviously and with the span length increases the variation becomes more obviously. The connecting stiffness brings small influence to the LLDF in hollow core slab bridges. And with the increase of skew angle, the LLDF of the new side slab changes obviously, but the variation of LLDF of original slabs is not obviously according to skew angle.