Analysis of Deformation and Disturbance of Underlying Tunnel Caused by Excavation and Unloading of Foundation Pit in Muddy Strata
In order to obtain the influence of mid-deep foundation pit construction on the deformation disturbance of the tunnel in the lower lying section,taking Yongjia Square deep foundation pit diagonal tunnel project as the example,the influence of foundation pit ex-cavation on the deformation of the tunnel was analyzed by combining the measured data with the three-dimensional numerical analysis method,and the rationality of the numerical model was verified.The results show that when the distance of the foundation pit bottom in the silt layer is about two times the tunnel diameter,the tunnel uplift deformation can be effectively controlled by using stirring rein-forcement measures on the upper layer of the tunnel.The maximum uplift deformation of the tunnel meets the requirements of deforma-tion protection.The larger the overlap length of tunnel and foundation pit,the larger the uplift deformation,and the uplift deformation gradually decreases from the overlap center point to both sides of foundation pit.When the overlap length of tunnel and foundation pit is large,there is a gentle uplift area in the overlap center,and the large-area excavation method of one-time unloading is not condu-cive to controlling the uplift deformation of tunnel structure.On the same tunnel section,the largest uplift deformation is located at the spinner and the largest horizontal deformation is located at the arch waist,and the tunnel shape is convergent deformation of"vertical ellipse".
万方数据
维普
