复合地基支护结构永久性集约化设计分析
Analysis on permanent intensive design of supporting structure of composite foundation

目前基坑工程多采用临时性支护措施，且各类地下工程及其结构往往永久共同存在。济南省会文化艺术中心(大剧院)台仓处于大面积CFG复合地基之中，基坑支护结构采用双排支护桩加一排预应力锚杆，双排桩兼作复合地基“一桩两用”。运用PLAXIS3D有限元软件建立三维单元模型，考虑复合地基、群桩基础与支护结构共同工作，实现支护结构侧压力的集约化设计。与常规基坑支护设计相比，该方案增加了支护结构耐久性设计，利用基坑主动区复合地基与被动区群桩基础对土体的加固作用，针对支护结构永久性构造措施等做了详细分析，工程建设取得良好效果，研究方法可为类似工程参考，基坑支护结构永久化和地下结构集约化设计观点应被业内接受和推广。
At present most supporting structures used in foundation pit engineering are temporary and all kinds of underground engineering and their structures often coexist permanently. Jinan Provincial Capital Cultural Arts Center (Theater) stage-bin is surrounded by a large area of CFG composite foundation. The double-row piles with prestressed anchor cables are used as the supporting structures as well as the composite foundation, that is “dual-purpose pile”. Considering the combined action of composite foundation, pile group foundation and supporting structure, a three-dimensional finite element model was established using finite element software PLAXIS 3D. The intensive design of lateral pressure of supporting structures was achieved. Compared with conventional design of pit supporting, the scheme adds the durability design of supporting structures. The permanent structural measures of supporting structures were analyzed in detail based on reinforcement effect of composite foundation in active area and pile group foundation in passive area. Good effects were obtained in the engineering construction. The research method may provide reference for similar projects. The design view of permanent supporting structures and underground structures intensification should be accepted and promoted in the industry