Theoretical analysis of three-dimensional ground displacements induced by shield tunneling

摘要

In this study, an approach to estimate three-dimensional ground displacements induced by shield tunneling is proposed by using the superposition method, advocating consideration of the ground loss as well as the working loads during shield tunneling. The ground movements caused by different factors, i.e., applied support pressures, shield shell frictions and cutter head rotation, are investigated in detail, which can provide a better understanding of how to set the shield advancing parameters for ground disturbance controlling. The main advantage of this approach is that it can well reproduce the uplift and settlement characteristics of the ground. It is also of great significance for assessing the safety of closely spaced structures when the ground differential settlement is taken into account. To estimate the ground movements induced by twin tunneling, an additional ground loss ratio is introduced to describe the disturbance caused by the first tunneling. The proposed approach in this paper is tested against the field data at a construction site and provides a satisfactory estimate of the ground movement.