Insights into Pipe Jacking-induced Ground Deformation Considering Dynamic Cutter Excavation Effect through Numerical Modelling

The pipe jacking method has been increasingly applied to a variety of tunnel projects. Investigating the ground disturbance characteristics during pipe jacking is of great significance to ensure accurate safety assessment and timely ground deformation control. This paper developed a three-dimensional model to simulate the entire pipe jacking process of a shallow-buried cross passage tunnel in soft strata. A key contribution of this research is the development of an element shear failure approach, combining element failure method with shear failure modeling. Meanwhile, the dynamic cutter excavation effect and the soil shear failure were considered in the numerical modeling. Through the comparison with the field monitoring results and traditional numerical simulation approach, the effectiveness, reliability, and superiority of the proposed approach were well demonstrated. Moreover, based on the numerical results, the ground deformation characteristics along with the stress-strain state of the cutter head during the soil excavating process were thoroughly analyzed. The proposed approach and its application in the ground disturbance analysis will offer useful references and guidance for numerical studies in similar pipe jacking projects in near future.