Construction Disturbance Analysis of Jacked Box Tunneling Overcrossing Existing Tunnel at Short Distance

With the application of jacked box tunneling in underground engineering construction, it is inevitable to cross the adjacent existing structures, and there is less research on the interaction between the new jacked box tunnel and the existing tunnel, especially in the dynamic simulation of jacked box tunneling. Taking a large section jacked box tunneling in Suzhou as the background, the deformation of the existing tunnel caused by the jacked box tunneling construction is measured on site. It is concluded that the area below the axis has the greatest impact on the existing tunnel, the sound range is about 2.5W (W is the jacked box tunneling width), and the tunnel presents an uplift trend as a whole. The three-dimensional finite element model is established, and the dynamic simulation of jacked box tunneling is performed by displacement control. On the basis of considering interaction between the soils and box linings, the influence law of friction on the adjacent tunnel is studied. It is concluded that the greater the lateral friction resistance is, the greater the tunnel uplift value is, and the simulation results are basically consistent with the field measurement, which verifies the correctness of the measured law and the rationality of the model.