地铁隧道施工竖井降水开挖引起的地表沉降分析

为评估城市地铁隧道竖井施工产生的地表沉降,结合深圳地铁5号线某暗挖区间竖井施工,采用有限元和流固耦合方法对该竖井的降水及开挖施工进行三维数值模拟分析,得到竖井降水和开挖引起地表沉降的变化和分布。根据地表沉降计算结果可得到如下结论:1)竖井单纯进行开挖而不降水引起的地表沉降远小于开挖和降水耦合作用引起的总沉降;2)距竖井越近,开挖引起的沉降占总沉降比例越大;距竖井越远,降水引起的沉降占总沉降的比例越大;3)在地表最大沉降处降水产生的沉降占到了总沉降的65%。

Analysis on Ground Surface Settlement Induced by Dewatering and Excavation of Vertical Shaft of Metro Tunnel Works

3D numerical simulation analysis by means of finite element and fluid-solid coupling methods is made for the dewatering and excavation of a vertical shaft of a running tunnel of Shenzhen Metro Line 5 constructed by mining method,so as to assess the ground surface settlement induced by the sinking of the vertical shaft.The variations and distributions of ground surface settlement induced by dewatering and excavation of the vertical shaft are obtained.Conclusions drawn are as follows： 1） The ground surface settlement induced by the excavation of the vertical shaft without dewatering is far smaller than that induced by the coupling effect of dewatering and excavation of the vertical shaft;2） The closer the measurement points to the vertical shaft,the larger the ratio of the ground surface settlement induced by excavation in the total value;the farther the measurement points to the vertical shaft,the larger the ratio of the ground surface settlement induced by dewatering in the total;3） At the position with the larest ground surface settlement,the settlement induced by dewatering occupies 65% of the total.