预应力混凝土刚构-连续组合梁桥的减震设计

Earthquake-reduction design for rigid frame-continuous girder bridge combined system

以324国道乌龙江大桥复线桥为工程背景,对刚构-连续组合梁桥进行两级设防地震水平下的地震反应分析及抗震验算.结果表明,在两级设防地震作用下,上部结构产生的纵桥向地震力主要由2号刚构墩承担;在E1地震作用下,组合梁桥满足抗震强度要求,但在E2地震作用下,组合梁桥的2号刚构墩无法满足抗震强度要求.为改善结构的整体抗震性能,对刚构-连续组合梁桥进行减震方案设计及比选.比选结果表明,仅在5号墩墩顶增设Lock-up装置,就可以较大幅度降低2号刚构墩的控制地震内力,满足预期的抗震设防目标,是一个优化的减震方案.

Baesd on the bridge cross the Wulong river on G324 state highway,seismic response analysis and strength verification for rigid frame-continuous girder bridge combined system under two design earthquake levels are conducted.The results show： the rigid fixed pier carries the most part of the longitudinal seismic load from superstructure of the bridge;the bridge can satisfy the strength demand under earthquake action E1,but the rigid fixed pier of the bridge cannot satisfy the strength demand under earthquake action E2.To improve the seismic performance of the bridge,a comparative study of several earthquake-reduction schemes for the bridge is carried out.From the comparison of the design schemes,it is found that adding several Lock-up devices on the top of No.5 pier of the bridge can largely reduce the seismic force of the fixed pier,and meet the expected seismic performance objectives of the bridge.