地铁盾构隧道下穿河流施工稳定性分析

盾构隧道施工过程中不可避免地需要穿越河流、湖泊和海洋等富水地层,由于地下高水压和水源的不断补给,在施工过程中可能出现较大的风险。下穿河流段的隧道与陆地隧道相比,不仅要承担土体的重力作用,还需承受较大的水压力作用,掘进难度较大且风险较高。以青岛地铁2号线二期工程下穿侯家庄河为工程背景研究盾构穿越河流对隧道的影响,通过建立三维有限元模型,模拟分析盾构施工过程对地表、隧道、河床沉降的影响。

In the process of shield tunnel construction,it is inevitable to cross water-rich strata such as rivers,lakes and oceans.Due to the high underground water pressure and the continuous supply of water sources,there may be greater risks in the construction process.Compared with the land tunnel,the tunnel under-passing the river section not only needs to bear the gravity of the soil,but also needs to bear the large water pressure,which is difficult to excavate and has high risk.Taking the second phase project of Qingdao Metro Line 2 crossing Houjiazhuang River as the engineering background,this paper studies the influence of shield crossing river on tunnel.By establishing a three-dimensional finite element model,the influence of shield construction process on surface,tunnel and river bottom settlement is simulated and analyzed.