基于功率谱法分析场地效应对大跨度连续刚构桥的影响

Influence on Long-span Continuous Rigid Framed Bridge of Site Effect Based on Power Spectrum Method

以一座全长为346 m的预应力混凝土连续刚构桥为基础,建立全桥计算模型,采用由规范反应谱生成的相应的功率谱,分6种工况对桥梁进行激励;通过多点激励与一致激励的对比,分析了场地效应对连续刚构桥的影响。结果表明:对于高墩大跨度连续刚构桥,场地效应主要对跨中截面不利,并使桥墩墩底内力产生突变。

A computing model of the entire bridge was established based on a prestressed concrete continuous rigid framed bridge, which was 346m. The bridge was to be excited under six working conditions respectively using the power spectrum generated from standard response spectrum. By compared multi-support excitation with uniform excitation, this essay analy- ses the influence of site effect on continuous rigid framed bridge. The research result indicates that for continuous rigid framed bridge of high piers and long span, site effect is mainly disadvantageous to the mid-span cross-section of girders, and can cause a abrupt change of internal force of the bottom of piers.