衡重式双排桩与大跨度支撑在填海区超大基坑支护中的应用

Application of Counterbalanced Double-row Piles and Large-span Support in Super-large Foundation Pit Support in Reclamation Area

以深圳国际会展中心项目(一期)超大深基坑工程设计为研究对象,为解决填海区超大基坑施工工期紧、变形控制要求高的难题,采用衡重式双排桩与大跨度支撑相结合的方法进行处理。建立该结构的支撑刚度计算模型,通过数值模拟研究大跨度支撑间距对支护结构变形及内力的影响。结果表明:该结构应用于填海区超大基坑时控制变形能力强,土方外运效率高;支撑间距变化对支护结构水平位移和内力影响显著,支撑间距合理区间为60~70 m。

Taking the design of the super-large and deep foundation pit of the Shenzhen International Convention and Exhibition Center project(Phase I)as the research object,in order to solve the problems of tight construction period and high deformation control requirements for the super-large foundation pit in the reclamation area,the method combining counterbalanced double-row piles and large span support was adopted.The support stiffness calculation model of the structure was established,and the influence of large-span support spacing on the deformation and internal force of the support structure was studied through numerical simulation.The results show that the deformation control ability is strong and the earthwork transportation efficiency is high when the structure is applied to the super-large foundation pit in the reclamation area.The support spacing change has significant influence on the horizontal displacement and internal force of the support structure.The reasonable range of support spacing is 60~70 m.