Interaction Analyses between Existing Pipeline and Quasi-Rectangular Tunneling in Clays

Abstract

Previous researches about geoenvironmental disturbance caused by tunneling have mainly concentrated on the influences of circular tunnel construction, but minimal interesting is given to the quasi-rectangular shield tunneling. Considering the convergence deformation model for quasi-rectangular shield tunneling at excavation face, the simplified closed-form solution is put forward to evaluate the deformation behavior for underground pipeline caused by quasi-rectangular shield tunneling. Firstly, the free-field displacements induced by the quasi-rectangular shield excavation are estimated by the point source technique. Secondly, characterized by the Winkler foundation, the free-field displacements are applied to the pipeline structures and a simplified analytical solution is obtained for analyzing the deformation of adjacent pipeline induced by quasi-rectangular tunneling. Through the analyses of engineering cases, the comparison between analytical solution for the free-field deformation and measured data is conducted. Meanwhile, the numerical simulation technique and the physical modelling tests for the pipeline deformation are utilized to compare the simplified analytical results. In addition, the primary parameters are conducted for the interaction mechanics between quasi-rectangular tunneling and existing pipeline, such as the pipeline diameter, the geometry size and centerline depth of pipeline and tunnel, the structural physics modulus of pipeline, the compressive modulus of ground, and the ground loss parameter. The results of this study are of great significance for exploring the geomechanical effects induced by quasi-rectangular shield tunneling in clays.