邻梁碰撞对系杆拱桥地震响应的影响分析

为研究邻梁碰撞对系杆拱桥地震响应的影响,以一座跨度64 m钢管混凝土简支系杆拱桥为研究对象,采用MIDAS/Civil建立全桥及邻跨简支梁桥的空间有限元模型,输入50年超过概率为0. 2%的罕遇地震波进行非线性时程反应分析。结果表明:邻梁碰撞对系杆拱桥拱肋、横撑及K撑的影响较大,对下部结构的影响较小;考虑竖向地震动后,结构各部件的内力整体增加,碰撞对拱肋及K撑的影响显著,横撑基本不受影响;竖向地震动可使得碰撞力及碰撞次数增加。建议在系杆拱桥的设计中考虑邻梁碰撞效应。

Analysis of Influence of Adjacent Beam Collision on Seismic Response of Tied Arch Bridge

In order to study the inf luence of adjacent beam collision on the seismic response of tied arch bridge,a 64 m concrete-f illed steel tube simply-supported tied arch bridge was taken as the research object.The spatial f inite element model of the whole bridge and the adjacent simply-supported girder bridges was established by MIDAS/Civil.The non-linear time-history response analysis of the tied arch bridge was carried out by inputting rare seismic waves whose probability of being exceeded was 0.2 % in 50 years.The results show that the adjacent beam collision has strong inf luence on the arch ribs,transverse braces and K braces of tied arch bridge,and has a relatively small inf luence on the lower structure.After considering the vertical ground motion,the internal forces of the structural components increase as a whole,and the inf luences of collision on the arch ribs and K braces are signif icant ,but the transverse braces are basically not affected.The vertical ground motion can increase the collision force and the number of collisions.It is suggested that the collision effect of adjacent beams should be considered in the design of tied arch bridge.