地震作用下考虑土-桥台-上部结构相互作用的大跨桥梁伸缩缝处碰撞效应研究  

Research on Pounding Effects at Expansion Joints of Long-span Bridge Under Earthquakes with Interaction of Soil,Abutment and Superstructure Considered

作　　者：邓育林[1] 雷凡[1] 何雄君[1] 

机构地区：[1]武汉理工大学交通学院,湖北武汉430063

出　　处：《中国公路学报》2015年第3期44-51,共8页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51378406)

摘　　要：为了给大跨桥梁抗震设计提供参考,针对西部山区强地震带常见的高墩大跨桥梁,考虑土-桥台-上部结构相互作用以及支座的滑动效应,采用非线性时程法对地震作用下大跨桥梁伸缩缝处碰撞效应进行了研究。采用非线性弹簧模拟桩基-土体相互作用以及台背填土的弹塑性变形,采用双线性滞回模型模拟支座的滑动效应,并采用接触单元法模拟主、引桥梁体间以及引桥梁体-桥台背墙间的碰撞反应。研究结果表明:主、引桥梁体间以及引桥梁体-桥台背墙间若发生连锁碰撞效应,桥台背墙将会遭受较大的撞击力作用,过大撞击力使得台背纵向位移、台后填土塑性变形以及桥台桩基的地震响应显著增大,易引起引桥桥台破损、桩基断裂以及引桥梁体落梁等震害。In order to provide reference for seismic design of long-span bridges,aimed at long-span bridges with high piers adopted widely in the strong earthquake belt of Chinese western mountains,with the interaction of soil,abutment and superstructure and sliding effects of bearings considered,by using nonlinear time history analysis method,the pounding effects at expansion joints of long-span bridges under earthquakes were studied.The interaction between piles and soil and the elasto-plastic deformation of the backfill soil were simulated by nonlinear springs.The sliding effects of bearings were simulated by bilinear hysteretic model.And the pounding responses between the main span and approach span and between the approach span and back wall of the abutment were simulated by contact element method.The results indicate that if the pounding at expansion joints between the main span and approach span and between the approach span and back wall of the abutment takes place,the back wall of the abutment will suffer greater pounding force which can significantly amplify the longitudinal displacement of the back wall,the plastic deformation of the embankment fill and the pile＇s seismic response of the abutment,which can easily cause more serious damages of the approach span such as abutmentdamage,pile foundation fracture and the unseating of the deck,etc.

关 键 词：桥梁工程 桥台 非线性时程法 碰撞效应 地震 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]