Prediction and Control of Ground Deformation and Displacement due to Large Slurry Shield Tunneling using Stochastic Medium Theory

Slurry shield tunneling has been successfully applied worldwide in recent years due to its virtues However, in a complicated environment, the prediction and control of ground surface deformation and displacement due to large slurry shield excavation remain important problems to be solved. This paper presents the analytical formulation for ground surface deformation and displacement induced by tunnel excavation based on a stochastic medium model. An optimization theory of Powell's Conjugation method was employed for the back-analysis prediction of settlement in this model. Based on ultra-large slurry shield tunneling in the building zone of Shanghai Yangtze river project, the ground surface movement induced by uplink tunneling as well as cumulative movement of uplink and downlink tunneling was accurately predicted using the associated program. Recommended procedures for tunneling in a building zone are also presented. The case study verifies the validity and reliability of the theoretical approach and can be serve as a reference for other similar engineering projects.