Seismic Damage Mechanism And Seismic Response Analysis Of The Shou Jiang Bridge In Wenchuan Earthquake

May 12 th,2008,an earthquake with Ms=8 occurred in Sichuan province in our hometown,which made a great deal of casualties.In this earthquake,due to the complexity,these high-pier bridges response is more complex than other bridges.Among them,high-pier bridge Shoujiang Bridge occurred in the more obvious earthquake damage.In this paper,The Shou Jiang bridge damage,for example,with SAP2000 structure are established calculation model.The seismic damage mechanism of Shoujiang Bridge is discussed by nonlinear time history method.The seismic response parameters are analyzed,this paper summarizes the seismic response characteristics of the high-pier bridge and the corresponding effective measures to reduce the earthquake.The main work and progress of this paper are as follows:(1)Introduced the background and significance of this study,discusses the classification characteristics of irregular girder bridge and the characteristics of earthquake damage,and introduces the development of seismic response analysis methods and research status.(2)Discusses the Wenchuan earthquake overall damage and seismic damage characteristic of bridges,introduced the research object Shou Jiang Bridge Engineering Survey and damage.Summarize Shou Jiang bridge main earthquake damage characteristics for: Damage of superstructure is mainly manifested as the longitudinal girder displacement,which caused collision and bearing,abutment,retaining block failure;The most serious damage to the piers is the first coupling structure of bridge,the piers bottom cracking.(3)Based on the analysis results,the seismic damage characteristics of Shoujiang Bridge are studied,and the damage mechanism of similar bridges is revealed.The analysis of the self-vibration characteristics of Shoujiang bridge shows that the basic period of span section of the bridge pier is quite different from that of the adjacent two-side short pier bridge,and the high-order mode contribution of the high pier bridge is greater;two non-linear It is found that there is a large displacement of the main girder of the model,the collision of the expansion joint occurs,and the slipping of the bearing is obvious.The similar mechanism of bridge damage is revealed: the large difference of self-vibration between adjacent beams leads to large non-isotropic motion of the main girder,which causes the collision of the joints,Slip and pier pier at the end of bending damage caused by excessive damage.(4)It is revealed that the collision effect is an important factor affecting the seismic damage of high pier bridges.The bridge piers are self-important and complexcity.They are easy to collide with adjacent structures or abutments.The collision at the joints will cause the displacement of the piers and the change of the moment at bottle of the pier.Reaction has a significant impact.(5)Based on the analysis of seismic damage mechanism of Shoujiang Bridge and the analysis results of parameters,the paper proposes a shock absorbing method.By comparing the finite element model of the device with the finite element model without considering the device,it is come to the conclusion that the effect of this measure on the structural damage is obvious.