上海世博会地下变电站基坑围护结构的动力反应分析

采用三维快速拉格朗日程序FLAC3D,对上海世博会500 kV地下变电站围护结构的动力反应问题进行了深入细致的分析和研究。所建立的模型采用摩尔-库伦本构关系,同时考虑了静力、动力以及地下承压水的影响,并且通过FLAC3D软件的二次开发功能引入统一强度理论,来判别围护结构中钢筋混凝土的应力状态,力求更真实地反映围护结构在动力作用下的响应状态。分析结果表明,圆型围护结构的环向刚度比较大,受力时将大部分侧向荷载转移给其环向拱结构,从而使得基坑和周围土体无论在静力状态还是动力状态下,整体变形均较小;基坑整体在所研究的各种工况下,围护结构都处于安全状态。

Analysis of Dynamic Responses of Enclosure Structure in an Underground Substation of Shanghai World Exposition

A three-dimensional fast Lagrangian program FLAC3D is adopted to conducted the detailed study on the dynamic responses of encloure structure in a 500 kV underground substation of the Shanghai World Expo.The Mohr-Coulomb model is used and static analysis,dynamic analysis and artesian water influence are included in this research.The unified strength theory is introduced to the model by secondary development in FLAC3D to determine the stress state of the envelope′s reinforced concrete for truly reflecting the responses of the envelope under the action of the dynamic force.The results show that the ring stiffness of the cylindrical enclosure structure is large.When it is forced,most of the lateral loads will be transferred to the arch structure in the ring direction,which controls the deformation of the pit and the surrounding soil in both static and dynamic conditions.The excavation as a whole is in a safe state in a variety of operating conditions.