土岩组合基坑安全风险预警标准探讨

发布时间：2018-04-17 07:56

本文选题：土岩组合基坑 + 破坏模式　；参考：《岩土工程学报》2014年S1期

【摘要】：土岩组合基坑的安全风险预警标准目前主要沿用现有相关规范中的监控标准,这种做法缺乏针对性。为了更有效地指导土岩组合基坑施工,对土岩组合基坑的破坏模式进行了定性分析,并对依托工程典型施工断面进行了三维有限元分析和现场监测,然后,深入对比分析了有限元分析结果和现场监测结果。研究指出:1围护墙的水平位移可作为主要的安全风险预警指标,支撑/土钉/锚杆轴力可作为辅助指标;2围护墙水平位移最大值、水平位移最大值变化速率、水平位移最大值与基坑开挖深度的比值、支撑/土钉/锚杆轴力值与开挖深度范围内土压力的比值等四个特征参数可作为土岩组合基坑安全风险预警指标特征参数;3建立了相应的安全风险预警标准体系,同时认为该依托工程土岩基坑的设计过于保守,从而导致过高的施工成本,因此有必要进行优化设计。
[Abstract]:At present, the safety risk early warning standard of soil and rock composite foundation pit mainly adopts the monitoring standard of the existing relevant codes, which is lack of pertinence.In order to guide the construction of soil-rock composite foundation pit more effectively, the failure mode of soil-rock composite foundation pit is qualitatively analyzed, and the 3D finite element analysis and field monitoring of typical construction section of supporting engineering are carried out, then,The results of finite element analysis and field monitoring are compared and analyzed.It is pointed out that the horizontal displacement of the 1 / 1 retaining wall can be used as the main safety risk warning index, and the axial force of the bracing / soil nailing / anchor rod can be used as the auxiliary index for the maximum horizontal displacement and the maximum change rate of the horizontal displacement of the retaining wall.Ratio of maximum horizontal displacement to excavation depth,The four characteristic parameters, such as the ratio of the axial force of bracing / soil nailing / anchor rod to the earth pressure in the depth of excavation, can be used as the characteristic parameters of the earth-rock composite foundation pit safety risk early warning index, and the corresponding safety risk warning standard system is established.At the same time, it is considered that the design of the foundation pit based on soil and rock is too conservative, which leads to too high construction cost, so it is necessary to optimize the design.
【作者单位】：中交四航工程研究院有限公司;中交交通基础工程环保与安全重点实验室;华南理工大学土木与交通学院;
【分类号】：TU753

【共引文献】