复杂环境下城市地铁隧道开挖方法的数值模拟分析

Numerical Simulation Analysis on Excavation Method of Urban Subway Tunnel in Complex Environment

石家庄市轨道交通2号线东港头站—新世隆站区间沿线存在多处建筑物、管道和热力隧道。为减小地铁隧道开挖对周边结构影响,选择最佳开挖方法,采用数值模拟计算软件FLAC^(3D)建立了三维模型,模拟了三台阶法和CRD法开挖过程,获得了拱顶沉降位移、地面沉降位移和支护结构应力值等数据。数值分析结果表明:相比三台阶法,CRD法模拟开挖引起的拱顶沉降、地面沉降更小,支护结构应力状态更稳定。最终确定CRD法为最佳开挖方法,为施工方案的优化提供了参考。

There are buildings,pipelines and thermal tunnel,along the section between Donggangtou Station and Xinshilong Station of Shijiazhuang Rail Transit Line 2.In order to reduce the influence of sub⁃way tunnel excavation on the surrounding structure and select the best excavation method,the 3D model was established by using the numerical simulation software Flac^(3D),the excavation process of three-step method and CRD method was simulated.The data of vault settlement displacement,ground settlement dis⁃placement and stress state of supporting structure were obtained.The numerical analysis results show that the vault settlement displacement and ground settlement displacement caused by CRD method are smaller and the stress state of supporting structure is more stable,which compared with the three-step method.Fi⁃nally,the CRD method is determined as the best excavation method,which provides a reference for the op⁃timization of construction scheme.