坑底软土夹层较薄基坑以最下层支点为轴心的滑动隆起研究

发布时间：2018-04-26 03:36

本文选题：基坑 + 最下层支点　；参考：《结构工程师》2016年05期

【摘要】：2012版《建筑基坑支护技术规程》对于锚拉式、内支撑式支挡结构,新增了当坑底以下为软土时,尚应以最下层支点为轴心的圆弧滑动模式验算基坑抗隆起稳定性的规定,并给出了解析解计算公式,该公式对基坑设计嵌固深度影响很大,大大增加了基坑支护造价。对坑底存在软土夹层基坑进行了有限元分析,得出了标准荷载作用下基坑位移变形云图、极限状态下基坑破坏机理的总位移增量云图。结果表明:软土夹层厚度较小的基坑,以最下层支点为轴心的圆弧滑动模式验算增加的嵌固深度,对于基坑位移影响较小、对破坏机理有一定程度的影响,只要有限元稳定安全系数满足规范要求,可以不进行以最下层支点为轴心的滑动模式验算。
[Abstract]:The 2012 edition of the Technical Specification for Foundation Pit support in Building, for the bolt-pull type, the internal support type retaining structure, added when the bottom of the pit is soft soil, the circular arc sliding mode with the lowest fulcrum as the axis should be used to check the stability of foundation pit anti-uplift. The formula for calculating the analytical solution is given. The formula has a great influence on the design depth of foundation pit and greatly increases the cost of foundation pit support. The finite element analysis of the foundation pit with soft soil intercalation at the bottom of the pit is carried out. The displacement deformation cloud diagram of the foundation pit under standard load and the total displacement increment cloud diagram of the failure mechanism of the foundation pit under the limit state are obtained. The results show that for the foundation pit with small thickness of soft soil intercalation, the increased embedded depth of circular arc sliding mode with the lowest supporting point as the axis will have little effect on the displacement of the foundation pit and a certain degree of influence on the failure mechanism. As long as the safety factor of finite element stability meets the requirements of the code, the sliding mode checking with the lowest fulcrum as the axis can be avoided.
【作者单位】：南昌大学建筑工程学院;
【分类号】：TU473

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