A modified lateral load distribution model for hollow slab bridges considering the connecting effect of hinge joints

The lateral load distribution (LLD) behaviours of hollow slab bridges are affected by slabs as well as connecting effects from secondary structural members. One of the most significant connecting effects comes from the hinge joint, which is seriously affected by its type and working state. The purpose of this paper is to develop a modified LLD model for hollow slab bridges in which the details of hinge joints are considered. First, the LLD proportions of a hollow slab bridge with newly built, damaged and strengthened joints are investigated from field tests. Second, the limitation that neither the type nor the working state of the joint is considered in the conventional LLD models is studied. Third, a parametric study is performed on different hinge joints. Then, a factor is proposed to adjust the stiffness coefficient, and a modified computing process of the LLD proportion is proposed to dismantle that limitation. The research results indicate that 1) Shallow, mediate and deep hinge joints can be expressed by 1/4, 1/2 and 3/4 area in contact, respectively. 2) The contact stiffness of a hinge joint in strengthen state is bigger than 5E9 N/m3, which in damaged state is smaller than 2E9 N/m3, and which in design state is between the limits. 3) The stiffness coefficient and the adjustment factor of each slab can be predicted by the numerical analysis, and then the deflection of each slab can be predicted by modifying the LLD computing process.