陡倾岩层深埋地铁车站2种施工方法的对比分析

Comparative Analysis of Two Construction Methods for Deep-Buried Subway Station in Steep Rock Formation

摘要: 以重庆市轨道交通陡倾岩石地层某大跨地下暗挖车站为例，采用3台阶法与双侧壁导坑法两种开挖方法进行施工过程的数值模拟，车站开挖后围岩应力、位移、塑性区及初期支护结构受力特征的对比分析表明：采用双侧壁导坑法比台阶法更有利于车站围岩的稳定，但其围岩应力、位移、初期支护结构轴力等相差较小，两种开挖方法均能满足车站围岩稳定性的要求。综合考虑施工进度、施工成本、灵活多变及施工难度等因素，3台阶法比较适合该车站及类似地质条件的地铁车站施工。

Abstract: Taking a large-span underground excavation station in the steep rocky stratum of Chongqing rail transit as an example, the three-step method and the double-side wall guide pit method are used to simulate the construction process. The comparative analysis of the surrounding rock stress, displacement, plastic zone and the initial support structure stress after excavation shows that the double-side wall guide pit method is more conducive to the stability of the surrounding rock of the station than the step method, but the surrounding rock stress, displacement, axial force of the ini-tial support structure and so on differ little, both excavation methods can meet the requirements of station surrounding rock stability. Considering the construction schedule, construction cost, flexibility and construction difficulty, the 3-step method is more suitable for the construction of this metro station and the similar stations and similar geological conditions.