东海大桥预应力混凝土桥墩抗震性能分析

Seismic Performance of Prestressed Concrete Bridge Column of East Sea Bridge

摘要:

建立了可以在循环荷载作用下考虑有、无粘结预应力筋影响的纤维模型分析方法并进行了验证.采用该方法建立了东海大桥引桥桥墩的分析模型.发现东海大桥引桥桥墩中采用的有粘结预应力筋对初始侧向抗弯刚度有影响,对侧向承载能力几乎没有影响,并且该种类型桥墩残余位移较大.为了改善桥墩震后残余位移,针对桥墩特点比较了几种预应力筋布置方式,证明在箱形墩的截面中心布置无粘结预应力钢铰线既可以满足正常使用阶段性能,又能提高桥墩的抗震性能.但是预应力的施加水平、预应力筋含量等关键参数的取值,需要进一步研究确定.

Abstract:

The fiber element analytical method for bonded and unbonded prestressing column under cyclic loading is proposed and verified,and then the fiber element model for the pier of East Sea Bridge is built.Study of quasistatic behavior shows that the bonded prestressing high-strength steel bars have obvious effect on the stiffness of the type of pier,and little effect on strength,and there is dramatic residual displacement of the pier of East Sea Bridge.To mitigate the residual displacement of the pier, different configurations of prestressing strands are considered.The hollow rectangular piers with the unbonded prestressing strands at the center of the cross section can satisfy the demands of serviceability limited state and have the most superior seismic performance.Further research should be focused on the prestressing ratio and the prestressing area of this kind of pier.