软土基坑双排桩加固有限元计算分析

Finite Element Analysis of the Double Row Piles Supporting the Deep Excavation in Soft Soils

通过昆明软土地区基坑双排桩失稳实例分析了导致失稳的原因,认为忽视软土场地软弱夹层存在及设计支护结构刚度严重不足是失稳的主要原因,结合现场实际情况,提出了三种加固方案,逐一采用有限元结合HS模型进行了分析计算,从内力和变形方面对比了各方案的加固效果,提出了方案（1）和方案（2）联合加固的思路,并采用有限元分析了该联合加固方案的效果。现场实施后,根据桩顶位移监测数据表明该联合加固方案是合理经济的,为今后类似工程提供了一定的借鉴作用。

This paper presents a case history of an evaluation of failure in the soft soil deep excavation supported by the double row piles.It is concluded that the neglecting of a soft and weak soil zone in the analysis as well as the insufficient stiffness in the supporting structure were the major causes of the failure.Three supporting mitigation approaches were proposed and each approach was examined by the finite element method using hardening soil（HS） model.The mitigation results were also ranked with internal stress and deformation aspects.The actual solution was the combination of Method 1 and Method 2.The construction monitoring data indicated that mitigation solution was successful.