大跨薄壁墩连续刚构桥抗震性能分析

以武汉在建的天兴洲大桥南岸引桥大跨度连续刚构桥为研究对象,运用AN SY S对其动力特性进行了分析.得到了成桥状态下结构的自振特性及有效振型参与质量,确定了运用反应谱法对地震作用进行振型组合时所必须的振型阶数,并结合反应谱法和时程分析法对该桥进行了地震反应分析,分别得到各概率地震作用下结构的反应最大值,同时比较了两种方法的分析结果.根据“三水准”设防原则,分析评价了该桥的综合抗震性能,为该桥的建设和抗震设计提供了参考,也为进一步研究该类桥型的抗震性能提供了分析基础.分析结果表明,该桥具有足够的抗震能力,能够满足预期的设计性能.

Antiseismic Performance Analysis of a Large-span Continuous Rigid Frame Bridge

Based on the engineering design case of a large-span continuous rigid frame bridge which is a south approach of Tianxingzhou bridge in Wuhan city,its dynamic characteristics are analyzed by using the finite element software package ANSYS.In this paper,dynamic characteristics and the effective mode participation mass under finish-bridge status are gotten,and the minimum effective number of modes for mode combination of response spectrum analysis is determined.In addition,the maximum seismic responses of this bridge obtained from both response spectrum method and time history analysis method separately are compared.Based on the characteristics mentioned above,according to three level security principle,the antiseismic performance of this bridge is also evaluated with these methods.Results obtained in this paper can be served as useful guidelines to the construction and seismic design of the bridge.This systematic work offers analytical basement and guidance on effective antiseismic design as well as theoretical research of this type of bridges.Results show that the bridge can offer enough antiseismic bearing capacity and meet the expected design goal.