The Analysis And Research On Anti-sismic Of Jindong Bridge

The Spanning capacity of suspension bridge is the largest in all bridge type,and at present bridges with over1000m span are almost all suspension bridges.; Because of smaller stiffness of large span suspension bridge and longer natural vibration period,spectrum characteristics of seismic waves can cause great influence on the seismic response.The propagation of seismic wave has a certain phase lag phenomenon in different bearing, also seismic wave has an effect on the seismic response;Pile foundation is not completely fixed, pile-soil interaction also has a little impact on it.As an important dynamic characteristics of structure,damping has an non-neglected effect on seismic response analysis.So,Accurately understanding the earthquake damage mechanism of suspension Bridges plays a particularly big role for the security caused by earthquake.This thesis takes Jindong Bridge as an engineering example and makes use of finite element software in order to analyze its dynamic characteristics and seismic response.The main research content are:1.To introduce the earthquake disaster and development status and structure characteristics of large span suspension bridge and discuss the research significance of this article.2.To introduce systematically the method of seismic response analysis,the influence factors of dynamic time history analysis and principal theory of calculation and design of suspension Bridges.3.To introduce free vibration theory and Jindong bridge project profile and to establish finite element modelling and give it an analysis for dynamic characteristics.4.To introduce earthquake environment in engineering site and the choice of seismic wave and input7seismic waves with different spectrum characteristic from Longitudinal, transverse and vertical directions to analyze time-histories response and to research traveling wave effect and pile-soil interaction the influence of damping ratio on seismic response performance.