深基坑支护中微型桩桩土耦合作用的数值模拟

Numerical simulation for pile-soil interaction of micro-pile in supporting of deep foundation pit

针对微型桩支护研究较少、支护设计标准不统一的现状,以山东省广播电视中心地下车库深大基坑工程为例,介绍了所采用的"微型桩+预应力锚杆"支护形式,并借助于FLAC3D软件进行数值模拟计算。尝试用Interface界面单元模型模拟桩土之间的作用,得到支护桩体和土体的位移、桩体内力以及桩土接触面应力的分布变化规律。与实际监测数据对比分析表明,计算值与实测值吻合较好,证明了该模型的合理性,为类似基坑工程的设计、施工提供了有益的参考。

There is a dearth of research on the supporting effect of micro-pile and no unified design code for supporting design.Based on a composite retaining support of micro-piles and pre-stressed anchors in an underground garage of Broadcast Television Center of Shandong Province,we apply FLAC3D to simulate the supporting system.In the simulation,interface element is applied to simulate the soil-pile interaction.The displacement values of the supporting piles and soil,as well as the law of stress distribution at interface are obtained,and the calculation data are compared with the monitored data,showing a well conformity with the monitored data in the sites.It indicates that the model is scientific and rational,which can provide valuable experiences for similar deep foundation pit projects.