城市地铁深基坑开挖实测与数值模拟分析

摘要

城市地铁施工中由于周边环境复杂,基坑开挖引起的土层扰动,可能会造成建筑物及地下管线破坏,甚至引起基坑失稳.以某地铁深基坑工程为背景,借助FLAC3D,建立了基坑开挖计算模型.现场实测与模型计算结果表明,计算值和实测值基本吻合,采用的计算模型可以近似模拟实际开挖过程.通过改变模型参数,研究了围护桩刚度、锚索倾角及锚索位置对围护体系受力和变形的影响,得出一些有益的结论,为保证城市深基坑开挖周边环境及围护结构安全,提供一定的参考.%Because of the complexity of ambience and the construction of city subway, foundation pit excavation can cause disturbance to the soil, and bring damages to the buildings and underground pipes,even the stability of foundation pit can be lost Based on the project of a deep pit,with the aid of FLAC3D, established the foundation pit excavation calculation model. The results showed that the calculation model can simulate the actual excavation process. By the change of model parameters, The author Summarized the influence of the retaining piles stiffness,the retaining system force and deformation, and drew some useful conclusions, and ensured the city deep foundation pit excavation and retaining structure security.