杨帆1，李红2

（1 南京城镇建设设计咨询公司， 南京 210036； 2 南京市长江河道管理处， 南京 210000）

［摘要］软土层的分布对于基坑围护结构水平位移、坑底隆起变形、地表沉降等会产生重要影响。通过数值模拟的方法研究软土层位于不同深度时对基坑变形和稳定性的影响。分析表明，当软土层位于坑底位置时，围护桩的水平位移会明显增加；当软土层位于围护桩底时，对围护桩的影响较小。当软土层位于坑底时，坑底表现出塑性隆起的特征、回弹变形量大。随着软土层埋深的增加，地表沉降量明显增大；当软土层位于坑底时，地表沉降达到最大值，而且地表最大沉降与围护结构水平位移呈现出明显的相关性。综合各种计算结果，当软土层的埋深处于基坑底部至围护结构底端这一范围时，对基坑各方面的影响最不利。

［关键词］基坑开挖； 软土层分布； 围护结构； 地表沉降

中图分类号： TU433 文献标识码： A文章编号： 1002-848X(2015)S2-0143-05

作者简介：杨帆，硕士，高工，一级注册结构工程师，Email：yangf@ctarch.cn。 

Study on the influence of soft soil distribution to the deformation and stability of

excavation under cantilever deformation mode

Yang Fan1, Li Hong2

(1 Nanjing City-Town Architecture Design & Consultants Co., Ltd., Nanjing 210036, China；

2 Nanjing Yangtze River Channel Management, Nanjing 210000, China)

Abstract: The horizontal displacement of guard structure, the heave at bottom and ground settlement is greatly influenced by the distribution of soft soil. The influence of soft soil location to the deformation and stability of excavation is studied through numerical simulation. Result shows that the horizontal displacement of guard pile increases obviously when soft soil is at bottom. The characteristic of bottom deformation is plastic heave, and the rebound deformation is obvious when soft soil locates at bottom of excavation. With the buried depth of soft soil increases, the ground surface settlement increases greatly, and the maximum settlement appears when the location of soft soil is at bottom of excavation. The maximum ground settlement is correlated to the maximum horizontal displacement of guard pile. In summary, when the buried depth of soft soil is within the range between the bottom of excavation and the bottom of guard pile, the excavation is in unfavorable situation.

Keywords: excavation; distribution of soft soil; guard structure; ground surface settlement