某高墩刚构桥抗震性能分析

Seismic Performance Analysis of a High Pier Rigid Frame Bridge

为合理评定高墩刚构桥的抗震性能,以某实际高墩刚构桥为算例,建立其非线性有限元模型,进行了E1,E2水准下的非线性地震时程反应分析,重点讨论了支座、桥墩以及地震碰撞反应结果,分析了不同水准地震动作用下该桥主要构件的损伤程度及地震碰撞对桥梁反应的影响,并基于现行的桥梁抗震规范开展该高墩刚构桥的抗震性能评定。结果表明:在E1水准地震作用下,该高墩刚构桥整体处于线弹性阶段;在E2水准作用下,支座、桥墩和系梁出现不同程度损伤,在EL Centro波作用下产生碰撞时,相应位置上的支座、桥墩受力情况均出现明显的阶跃现象,但未出现严重的结构损伤。两水准地震作用下该高墩刚构桥均符合抗震设防目标。

Aiming to reasonably evaluate the seismic performance of a high pier rigid frame bridge,an actual high pier rigid frame bridge was taken as an example and established its nonlinear finite element model to carry out the nonlinear seismic time-history analysis under the level of E1 and E2.This analysis is focused on the support saddle,pier,and seismic pounding response.It analyzes the degree of damage to the main components of the bridge and the impact of seismic pounding on the response of the bridge under different levels of seismic action.It evaluates the seismic performance of the high pier rigid frame bridge based on the current seismic code of bridges.The results show that under the E1 level seismic action,the high pier rigid frame bridge example is in the line elastic stage;under the E2 level action,support saddle,pier,and tie beams have different degrees of damage.When a collision occurs under the action of EL Centro wave,the support saddle and pier stresses on the corresponding position have apparent step phenomenon but no resultant severe damage.The example bridge under the two levels of seismic action is in line with the seismic defense target.