Responses of adjacent underground jointed pipelines induced by tunneling

The excavation-induced soil settlement will induce extra deformation and bending moment on nearby buried pipelines, even damage. The soil movement by tunnel excavation is imposed to the buried pipeline directly. Based on the Winkler subgrade model and fictitious nodes to consider the mechanical property of joints of discontinuous pipelines, a simplified theoretical method is proposed to analyze the behavior of discontinuous buried pipelines under tunnel excavation. Through comparisons of the results of elastic analysis, centrifuge tests and a case study, the rationality of the proposed method is proved. Then the applicability of the proposed method in non-homogeneous soil is discussed by comparing the results with the solutions of the layered elastic theoretical method. Based on parametric studies, it is found that treating discontinuous pipelines as continuous ones is not rational.