Seismic Response Analysis Of Seismic Behavior Of Isolation Bearing And Soil-structure Interaction

In recent decades,the frequent earthquakes have brought great damage to human beings,and the bridge damage caused by earthquake is also very common.In view of this,many researchers around the world have done a lot of researches on the bridge seismic resistance,and they have also designed a variety of isolation bearings to reduce the damage to the bridge.With the intensive study on soil-structure interaction,it is found that the soil-structure interaction has great influence on the bridge seismic response.This article is based on a large number of relevant literatures and the research status.The effects of seismic performance and soil-structure interaction on the seismic response of the bridge are studied.The specific works are as follows:(1)A brief introduction about the structural characteristics and principle of lead rubber bearing.The domestic and foreign research status of the lead core rubber bearing and soil-structure interaction,and the relevant theoretical kNowledge,are summarized.(2)The seismic performance of multi lead core rubber bearing is studied based on the combination of tests in test room and numerical simulation.Firstly,for the multi lead core rubber bearing,the unidirectional compression-shear test is carried out,an accurate finite element model is set up,and the numerical simulation of bidirectional compression-shear under all kinds of working conditions is made.Then,for the single lead core rubber bearing,an accurate finite element model is established,and the mechanical properties of the multi lead core rubber bearing and the single lead core rubber bearing under the same working condition are compared.Finally,the adjustment methods under earthquakes for the mechanical properties of multi lead core rubber bearing are proposed.(3)Based on the vibration test and numerical simulation to practical bridges,the common soil-structure interaction simplified models are compared and analyzed.Firstly,the single-pier basement consolidation model,the spring-represent-soil model,the lumped parameter normalized model,the Boulanger model and the interface contact element model are established.Secondly,compare the calculated modals with the practical measured values of single pier,and adjust the parameters of the above simplified models to make the numerical simulation values are close to the practical measured values.Thirdly,the whole bridge seismic response analysis model is established based on the parameters-adjusted soil-structure interaction models.Finally,compare the calculated whole bridge modals with the practical measured values,and choose the model in which the modals are the most close to the practical values as the soil-structure interaction simplified model.(4)Based on the above research results,establish the finite element models of different types of bridges,input three-dimensional ground motion and analyze the seismic response.Then the effects of isolation bearing's seismic performance and soil-structure interaction on the bridges' seismic response are researched.Next,the internal forces at pier bottom and the displacements at pier top of soil-structure interaction model and basement consolidation model under the same earthquake are compared and analyzed.Last,with consideration of soil-structure interaction and horizontal bidirectional constitutive,the internal forces at pier bottom and the relative displacements of pier and beam before and after adjusting the isolation bearing's seismic performance are compared.