深基坑挡土桩土拱效应特征分析

Feature Analysis on Soft Arching Effect of Retaining Piles for Deep Foundation Pit

摘要:

土拱效应是挡土桩工作原理的基础。采用有限元法首先研究了一个真正土拱的受力特征，以此为基础，分析了深基坑挡土桩后土体的受力状态；指出挡土桩后的土体可以分为3个区域：拱底应力区、土拱区和拱顶均匀应力区。在拱底应力区，最大主应力为拉应力；在土拱应力区，其受力特征与真正的土拱相同。给出了这3个区域的分界线特征，并讨论了荷载及挡土桩净距等因素对土拱区形状的影响。

Abstract:

Soil arching effect is the basis for retaining piles.In this paper,FEM is first used in the study of stress and deformation for a real soil arch,and then based on it,stress and deformation condition behind retaining piles for deep pit is analyzed.The soil behind retaining piles can be divided into 3 region:(1) the region under soil arch,(2) soil arching region,(3) uniform stress zone in crown arch.In region(1),the maximum principal stress is tensile stress;the stress state in region(2) is the same with that of the real soil arch.The boundary of these 3 regions is studied.The influence on the structure of soil arching region by loading and clear space of retaining piles is also discussed.