砂卵石地层地下水对盾构隧道影响的离散元流固耦合分析  

Discrete Element Solid-fluid Coupling Analysis of Influence of Groundwater on Shield Tunnel in Sandy-cobble Strata

作　　者：王俊[1] 何川[1] 李栋林[1] 齐春[1] 周晓军[1] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《隧道建设》2016年第6期710-716,共7页Tunnel Construction

基　　金：国家重点基础研究发展计划(973)项目(2010CB732105);国家科技支撑计划(2013BAB10B02;2013BAB10B04)

摘　　要：为探明砂卵石地层中地下水对盾构隧道衬砌上的土压力以及地层变形的影响,以成都地铁2号线为依托,采用颗粒流方法,从细观角度模拟分析地下水对盾构隧道衬砌荷载分布以及地层扰动的规律,研究盾构隧道动态施工过程中及后期稳定后的水、土压力分布。研究表明:考虑地下水工况时的衬砌荷载小于不考虑地下水的工况,开挖后地下水位越高,衬砌荷载越小;地下水分布影响隧道开挖后洞周应力重分布,拱顶处受到的影响最大,拱肩处受到的影响最小;盾构隧道开挖后,拱顶上方存在一定范围的松动区,在松动区上方一定范围形成坍落拱,起到承载作用,同时将上方土荷载有效地传递到洞周两侧。考虑地下水时,由于有效应力减小,地层变形相应减小,地层受盾构施工扰动的影响减弱。The influence of groundwater on load distribution of shield tunnel and ground deformation of Chengdu Metro Line No. 2 is analyzed microscopically by means of particle flow cate in two dimensions（ PFC2D） method. The soil stress and water stress during shield tunneling and after shield passing are studied. The study results show that： 1） The stress on tunnel lining structure considering groundwater is smaller than that without considering groundwater; and the higher the water level is,the smaller the stress on tunnel lining stress is. 2） The stress redistribution of surrounding rocks is affected by groundwater after shield passing; and the arch crown is affected mostly and the arch shoulder is affected minimally. 3） The loose zone above tunnel arch crown bears the soil load; as a result,the effective stress on the tunnel is decreased and the deformation of the tunnel can be decreased.

关 键 词：成都地铁 砂卵石地层 地下水 盾构隧道 颗粒流 

分 类 号：U452.27[建筑科学—桥梁与隧道工程]