管幕预筑法竖井设计在国内尚无相应规范,施工过程中其支护结构与周围土体的变形受力特性与安全性尚需进行研究.以某管幕预筑法地铁车站工程为例,利用有限差分软件FLAC3D对其竖井施工过程进行数值模拟,并结合施工监测数据进行对比分析,得到竖井支护结构及周边土体的位移与支撑轴力随施工过程的变化规律和特征.研究结果表明:管幕预筑法竖井施工过程对周边土体的变形影响较小,反映竖井新型支护结构的变形控制效果很好；顶管对各部分支护结构及周边土体的影响规律各不相同,主要体现在顶进过程中具有明显的时间性.%Pipe-roof pre-construction method (PPM) is a new construction method of substructure, its design codes is unavailable. The deformation and stress characteristics of retaining structure and surrounding soil need to be studied. Taken a metro station project constructed by PPM for example, FLAC3D was used to simulate the whole process which includes excavation, applying internal bracing and pipe jacking, the simulation results were comparatively analyzed with the construction monitoring data. The variation characteristics in deformation and bracing stress of retaining structure and surrounding soil were obtained. The results show that the deformation of the retaining structure and the surrounding soil is small during construction process, which indicates that the control effect of deformation is notable. The effects of pipe jacking process on retaining structure and surrounding soil are different with jacking process and layers, having obvious time-related characteristics.
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