Seismic Response Analysis On Long-span Continous Arch Bridge

Stone arch bridge is a common structure that has been widely built in our nation(especially in the southeast region), most of them built in sixties and the seventies last century. the location in areas of frequent eruption of earthquake and the poor seismic performance of arch bridge, Once destroyed it will bring great damage to thelives and properties.It neeessary to make an indepth study and analysis to the seismie performance of these bridges, which is an important faetor for safety. In this thesis,choosing the commonly used multi-span empty arch bridge as project background. carry out the seismic response with the finite element analysis software ANSYS. The main content this thesis includes:1. this paper establishes bridge space finite element model,compares arch bridge and multi-arch bridge the dynamic characteristics under the same boundary conditions. The numerieal results show that:Compared with the arch bridge,the natural frequency of the same span multi-arch bridge is lower.2. According to specific structure and construction sites geological characteristics of the project in this paper,choose the standard response spectrum curve and suitable damping-modified formula and modified the response spectrum curve. Inputing the modified response spectrum curve along the longitudinal, transverse and multidimensional direction-horizontal combined vertical, the internal force and displacement of the control sections are gained.3. The El_Centro earthquake wave(1940) is chosen to analyze the seismic response of the arch bridge and multi-arch bridge with dynamic time-history analysis considering the nonlinear factors which under the same load case and combination condition. Under different earthquake input, the internal force and displacement of the control sections are gained from two model. The seismic response is gained after comparing the calculation results of the two methods detailedly.4. Based on the anslysis of seismic response to arch bridge and multi-arch bridge,some conclusions are gaven out. Besides, the further research problem are indicated.