深基坑在组合支护下的三维模拟及监测分析

Analysis on Deep Foundation Pit under Combined Support Structure by 3D Simulation and Monitoring

深圳汉国深基坑工程,为确保安全,采用了桩撑(包括圆形内支撑)和桩锚的组合支护结构。通过三维数值模拟,同时结合在施工开挖过程中的监测数据,对桩锚撑组合支护结构的内力以及变形规律进行分析和总结。结果表明:灌注桩桩顶位移及内力计算值与模拟值差距较小,其发展趋势基本一致,三维有限元计算结果可信。三维有限元模型可以较好地考虑地下空间效应对支护结构内力及位移的影响。监测结果表明:组合支护结构能够确保深基坑工程的安全。

Taking Hanguo deep foundation pit engineering in Shenzhen as an example,a combined support structure of pile-strut （including circular inner support） and pile-anchor was used for the sake of safety; then the internal force and deformation rules of such pile-anchor-strut combined support were analyzed and generalized with 3D numerical simulation and the monitoring data from the excavation.The result of the analysis shows that,for cast-in-place piles,the calculated and simulated values of the pile top displacement and internal force have little difference and present substantially the same trend of development,thus the results from the 3D FEM calculation are dependable.The 3D FEM model could include the influence of underground spatial effect on the internal force and displacement of the support structure well.The result of the monitoring shows that the combined support structure ensures the safety of the deep foundation pit engineering.