考虑流固耦合的富水软土盾构施工地表沉降分析

Surface settlement analysis of shield construction in water-rich soft soil considering fluid-solid coupling

目前针对富水软土地层盾构施工过程中的地表沉降问题还缺乏足够的理论研究.以青岛地铁8号线盾构隧道穿越富水软土地层段为工程背景,基于流固耦合原理并采用FLAC 3D数值软件,对在地下水和地表水共同作用下盾构施工引起的地表沉降问题进行了分析.研究结果表明:地表横向沉降槽呈高斯分布;地表中心点随掌子面推进的纵向沉降曲线呈拉伸的“Z”形;地下水作用对地表沉降有较大影响,地表水影响相对较弱.所得结论将对富水软土地层中实际地铁工程建设提供一定的指导和借鉴.

At present,there is still a lack of sufficient theoretical research on the surface settlement in the construction process of shield tunneling in water-rich soft soil layer.Taking the shield tunnel of Qingdao Metro Line 8 through the water-rich soft soil layer section as the engineering background,and based on the fluid-solid coupling principle and FLAC 3D numerical software,we analyzed the variation law of surface settlement,which was caused by shield construction under the joint action of surface water and groundwater.The results show that the horizontal settlement tank of the surface displays a Gaussian distribution;the longitudinal settlement curve of the central point of the surface with the advancing of the working surface shows a stretching"Z"shape;the effect of groundwater has a great influence on the surface settlement,and the influence of surface water is relatively weak.The findings of the study will provide some guidance and reference for the actual subway construction in the water-rich soft soil layer.