PC连续刚构桥最大悬臂施工阶段稳定分析

Stability Analysis during the Construction Period of Maximum Cantilever of PC Continuous Rigid Frame Bridge

结合重庆市巫山县某预应力混凝土连续刚构桥,利用大型通用有限元分析软件Ansys10.0建立其有限元模型,采用线弹性稳定分析方法对其最大悬臂施工状态下不同荷载工况的稳定性进行对比分析,得到了桥梁各个典型工况下的一阶失稳特征值和失稳模态。分析结果表明施工期最不利工况下该连续刚构桥的稳定性满足规范要求,其稳定安全储备是足够的。并对最大悬臂状态下挂篮坠落对结构的冲击作用进行了动力响应分析。在以上分析的基础上,对安全施工提出了一些建议。

The finite element model of some prestressed concrete continuous rigid frame bridge in Wushan Chongqing is established by ANSYS10.0.The first order instability eigenvalue and instability modality in each typical working condition are obtained by comparative analysis on the maximum cantilever stability of different load case in construction state through linear elasticity stability analysis.Analysis results show that the stability of the continuous rigid frame bridge meets specification requirement and its emergency capacity is adequate under the worst working condition during construction period.The dynamic response analysis of the impact effect to the structure caused by cradle falling under the maximum cantilever state is conducted.Some proposals for safe construction are proposed on the basis of the above analysis.