Seismic Response Analysis Of Long Span Cable-Stayed Bridges With High-Low Tower

The earthquake is vibrating phenomenon caused by some a interior of the earth violent movement, which is the one of most devastating nature disasters. There are many violent earthquake in world last twenty years, especially 2008 year. A violent earthquake occurred at WENCHUAN in Sichuan province. This earthquake caused lots people injuries and deaths, destroyed many buildings and bridges, wrecked railways and highways, which completely broke off whole traffic in the epicentral area. It made relief work serious difficulties. The traffic system plays a major part in the earthquake relief work. So the diagonal cable bridge in particular being the pivotal project of communication, needs high investment, and has great weight with national economy. If it comes to the earthquake, it must be difficult for repairing and need more money, and whole transport network must break down. It will cause enormous economic losses. So it's of momentous current significance for making seismic design of diagonal cable bridge correctly and effectively and ensuring safety in service when the earthquake occurs.To the outsize bridge between YIBIN and CHONGQING on" Chengdu-Zigong-Luzhou" project for the project background.This thesis completely analyzed and discussed in details the bridge's seismic response and vibration performance by MIDAS, and carried out some discipline and conclusion as a source of reference for the seismic analysis of the kind bridge.The main contents included:(1) Consulting some Domestic and Foreign documents and materials about earthquake, diagonal cable bridge and seismic design, and summing up them to be an introduction.(2) Consulting the documents and material about seismic response analysis of bridge. Listing three methods of the seismic analysis, i.e. the response spectrum method, the dynamic time-history method and the subjunctive advocate approach of random vibration method.(3) Simply introducing the background of "Chengdu-Zigong-Luzhou" project and the finite-element method, using MIDAS to establish model for analysis of dynamic characteristics.(4) To regard to ground motion parameter defined by spatial safety report as seismic excitations input, doing dynamic response spectrum analysis. By contrast the different influences under the method of modal combination, the subsidence ratio, vertical seismic analysis and different seismic wave input, carrying out some of the results for reference.(5) Based on the vibrational acceleration time-history input defined by spatial safety report, doing seismic time-history response analysis. By contrast the different influences of soil-pile effect, side span ramp bridge, reduction of angular rigidity and traveling wave effect, the conclusions were drawn from analyzing the results of the response spectrum analysis and the time-history response analysis for reference.