武汉地铁名都站深基坑围护结构水平变形分析与仿真模拟研究

Horizontal deformation analysis and simulation study on protective structure of deep foundation pit in Mingdu Station of Wuhan Subway

以武汉地铁二号线名都站深基坑工程为研究对象,对现场监测数据进行了详细分析。采用有限元数值分析方法,借助于著名的岩土工程软件MIDAS/GTS建立了三维工程地质仿真计算模型。根据基坑现场实际开挖情况,采用弹塑性摩尔—库仑本构方程和实际应力与位移边界条件,计算得出了不同施工工序条件下基坑围护结构同一断面对应的基坑围护桩的位移云图和变形曲线,从而对深基坑分步开挖过程中支护结构的水平变形规律进行了研究,并将计算结果与监测结果进行了对比分析。结果表明:计算结果和监测数据基本吻合,说明模型和参数的选取及施工阶段的划分是合理的,且计算结果能较好地模拟深基坑开挖过程中围护结构的变形特性。研究成果对模拟超前开挖基坑并预测其变形特性具有积极的科学性,对下一步施工防护方案的及时修正具有重要的指导意义。

The deep foundation pit in Mingdu Station of Wuhan Subway Line 2 is used as the study background and the in-situ monitoring data are analyzed in detail. The cloud pictures describing the displacement of excavation and deformation curves are obtained under various schemes, and the force and deformation of the protective structures of the deep foundation pit considering step braced excavation are studied in detail by using FEM simulation software MIDAS. The results obtained from the numerical simulation are basically consistent with the field data, which show the selection of parameters and the division of the construction process is reasonable and the results of calculation could better simulate the deformation characteristics of the protective structure in the deep pit excavation. It is of the positive scientificity for simulating excavation pit ahead of time and predicting its deformation characteristics in the foundation pit, and it is significant for the timely revision of the schemes in the next construction process.