Seismic Response Analysis Of High Speed Railway Long Span Seismic Isolation Cable-Stayed Bridge Considering Pile Soil Influence Near Fault

At present,there are many long-span bridge projects built or under construction in China.Near-fault earthquake brings us more and more profound thinking in bridge construction and use,which poses great challenges to the analysis of seismic isolation reduction of long-span cable-stayed bridge of near-fault high-speed railway.In the future,the problems of overall structure,driving safety and post-earthquake repair of high-speed railway Bridges in China under the action of near-fault earthquakes are all urgent to be solved.In this paper,the Yujiang Double-track super large bridge with two towers and two cable planes and cable-stayed steel truss continuous girder bridge on Nan-Guangzhou Railway is studied.Based on ANSYS finite element software,two different bridge structures with and without pile-soil action are established,and the dynamic responses of high-speed railway long-span Bridges under different seismic actions with or without pulse near faults are analyzed by p-y method and M method.Different soil parameters are controlled quantitatively to study the response law of highspeed railway long-span bridge.In this paper,the effect of damping and isolation on Bridges is analyzed by the traditional way of setting lead core rubber bearing separately,setting viscous damper separately and combining the two methods,and a new directional conversion bearing is proposed.This paper mainly completed the following work:（1）The full bridge model of high-speed railway long-span cable-stayed bridge is established by using ANSYS finite element software.The near fault pulse type,near fault non pulse type and far-field seismic waves of Pacific earthquake research center are selected as the research data to analyze the dynamic response of bridge structure,and the influence of three kinds of earthquakes on the dynamic response of bridge structure is analyzed.（2）respectively,under the condition of considering the presence of pile-soil interaction in p-y method and m method,the dynamic response of bridge structure under the different ways of analysis,get the bridge vibration should not only consider the constraints of piles and soil at the same time,especially need to pay attention to the change of displacement range,and rarely met earthquake in high intensity areas appropriate USES analysis method of p-y.（3）Comparing the different seismic effects of the traditional arrangement of lead rubber bearing and viscous damper and the simultaneous arrangement as a joint scheme,a new vibration reduction and isolation device-direction conversion bearing is proposed.It is proved that the effect of reducing inertial force is obvious and the effect is better than the traditional vibration reduction and isolation bearing.