深基坑桩锚支护体系位移数值分析

利用大型有限元分析软件ADINA,考虑土的非线性和基坑分步开挖原则,以郑州楷林大厦深基坑为例,按照实际基坑开挖与支护的施工步骤,建立三维有限元模型进行数值分析,得到支护结构与土体随基坑开挖过程的变形规律及影响因素:支护桩水平位移最大点在基坑中上部,预应力锚杆对限制基坑壁的侧移起着至关重要的作用;基坑支护桩后主动区域受扰动最大的土层在桩体深度以下,支护结构入土深度加大,可有效控制土体向坑内流动;基坑外侧地表沉降呈现抛物线形状,在距离支护结构约1.5倍开挖深度处出现沉降最大值。

Numerical Analysis on Displacement of Pile-Anchor Supporting System in Deep Excavation

Taking Zhengzhou Kailin Mansion as an example and taking into account the nonlinear property of soil and the principle of sequential excavation, the authors establish a 3D FE model by using the large finite element software ADINA and sum up the deformation rule and influencing factors for supporting structure, when the foundation pit is excavated. The following conclusion can be drawn: the maximum of horizontal displacement is located at the middle-upper part of the pile. The prestressed anchor plays an important role in limiting the displacement of foundation pit side. The largest soil disturbance is below the pile body depth where the soil layers are in the active region after the foundation pit supporting pile was set. With the depth of supporting structure in the soil increases, the soil flowing to the pit can be effectively controlled. The form of surface settlement outside the pit is of parabolic shape. The maximal settlement is at about 1.5 times of the pit depth from the supporting structure.