An analytical solution for landslide impact on buried continuous pipelines

Abstract

Transverse permanent ground deformation (PGD) induced by landslide can exert excessive soil restraints on buried pipelines and threaten the pipeline safety. However, there is a lack of effective analysis model to assess the landslide-pipeline interaction. In this work, an analytical solution for calculating the responses of an existing continuous pipeline affected by landslide is presented, in which the pipeline and the subgrade are modelled as a Timoshenko beam and Winkler foundations, respectively. The proposed approach is evaluated by well-documented results of model testing on laterally loaded pipes and finite element analyses on landslide-pipeline interaction. Subsequently, safety assessments of pipelines are parametrically studied with respect to the dimension of transverse PGD, pipe size, and relative rigidity factor. It is found that the pipe deflection and strain depend greatly on the width of PGD zone. Pipeline could appear local buckling for all power parameter (N) values, and tensile rupture appears in the pipe when N ≥ 2.2. The unsafe condition of the pipeline occurs when the maximum PGD is δ ≥ 1.1 m. For the safety pipe design, the pipe diameter is a key factor rather than the pipe wall thickness, and the relative rigidity factor should be controlled at a lower value.