原支护结构部分拆除后基坑稳定性数值分析  

Numerical Analysis on Stability of Foundation Pit after Partly Demolition of Original Support Structure

作　　者：刘红岩[1] 李厚恩[1] 张晓科[1] 秦四清[1] 

机构地区：[1]中国科学院工程地质力学重点实验室,北京100029

出　　处：《建筑科学》2007年第5期23-27,共5页Building Science

摘　　要：在对FLAC3D中的土体本构模型及桩锚连接模型进行讨论的基础上,采用数值模拟手段对某基坑部分支护体系进行拆除后的基坑稳定性进行了数值分析。模拟结果表明:第3、4层锚杆锚固端拆锚以后,桩体最大水平位移达到2.58cm,几乎为6、7两种工况下的1.5倍;第2层锚杆的轴力增加很大,其最大值达到4.13e5N,为6、7两种工况下的2.3倍,为设计值的1.9倍;桩身弯距最大值达到8.0N.m,几乎是6、7两种工况下的最大正弯矩值3.0倍。所以可以认为,在不添加任何其他支护措施的情况下对这两层锚杆进行直接拆除是十分危险的。On the basis of discussing the soil constitutive model and link model of pile and anchor in FLAG^3D , the numerical simulation method is adopted to analyze the stability of the foundation pit after partly demolition of the original support structure. The simulation results show that the maximal horizontal displacement reaches 2.58cm, nearly 1,5 times that of the sixth and seventh conditions after demolition of the anchorage end of the third and fourth layer bolts. The axial force of the second layer bolt increases gready and the maximal value reaches 4, 13eSN, which is 2.3 times that of the sixth and seventh conditions and 1,9 times that of the design. The maximal moment of the pile reaches 8.ON· m, which is almost 3.0 times that of the sixth and seventh conditions, Therefore, it can be considered that it is very dangerous to directly demolish the two layers belts without adding any other supporting measures.

关 键 词：基坑 桩锚连接 锚杆轴力 支护结构拆除 

分 类 号：TU472.32[建筑科学—结构工程] TU753.3[建筑科学—土工工程]