Research On Damage Of Bridge Pier Under Impact Load Of Rockfall

Because of the special geography location, mountain bridges are often under the threat of all kinds of geological disasters, especially in mountainous areas of Minjiang river valley in Sichuan province, stones often rolling along the road. Accidents of bridge damage caused by rockfall occurred frequently, which affected the normal use of the bridge seriously. It is necessary to carry out the research of damage for bridge under the impact load of rockfall in mountain area.This thesis consists of two parts:The first part mainly introduced the theoretical foundation of finite element method for rockfall collision. Described the principle and control method of the hourglass effect in numerical simulation; introduced the numerical model in detail, including the material constitutive model selected in this paper, the geometric and finite element model of the piers, and the different load case.The second part is the numerical analysis. Firstly, established circular, rectangular, oval shaped piers numerical model by the finite element software LS-DYNA. Studied the dynamic response and failure law of different section piers under the impact load of rockfall by comparing the contact force, displacement of bridge pier, concrete failure volume rate and residual energy of reinforced concrete. Secondly, compared the dynamic response and failure law of rectangular piers with different ratio of length to width, cylindrical piers with different upper loads and different boundary conditions. Finally, studied the dynamic response and failure law of cylindrical pier and rectangular pier under the impact load of different shapes of rocks.