新建暗挖通道邻近既有区间安全性影响分析

Safety Influence Analyses of the New Channel Adjacent to Existing Running Metro

基于某地铁暗挖站的临时横通道的开挖施工对其邻近的既有地铁隧道结构可能带来的结构安全影响,从数值结构分析的角度,建立地层力学模型,考虑了初始平衡状态、施工开挖过程导致沉降变形又再次引起新的平衡状态等,给出了关键截面处的实际内力在几个不同过程中的变化数值,并与结构的极限承载力进行比较,以此判断结构的安全性。同时,分析各阶段引起的既有区间结构变形缝位置的水平及竖向差异变形,判定是否满足行车运营的安全。这些成果对于进一步合理设计与施工及进行既有结构的安全观测具有重要的参考意义。

Based on practical projects of the existed metro tunnels while the temporary transverse channels of the excavation station are constructed, some safety behaviors of tunnel structures are discussed from the views of numeri- cal analysis of structural mechanics. Initialized equilibriums, process of temporary transverse channels construction leading to settlements, newly initialized equilibriums, etc. are considered in this paper. Practical internal forces of key cross-sections at one of the steps are given and compared with the ultimate bearir^g ~apacity of the structure in or- der to judge their safety. At the same time, analysis of the various stages of deformation caused by both horizontal and vertical deformation difference position of interval structure was carried out to determine whether the train operation was safe or not. All these are important for further design and construction and safety observation for existed structure.