Mechanical response for rainfall-induced landslides on jointed gas pipelines

Current theoretical solutions for the influence of landslides on existing structures are generally conducted on the assumption of fine weather and provide little attention on the rainfall intensity and duration risk. Furthermore, previous studies on the interaction mechanics between landslides and pipelines seldom take account of the impacts of joints. This paper provides an analytical method to estimate the deformation and internal force of jointed gas pipelines caused by landslides considering the rainfall infiltration mechanism. By introducing the modified Green-Ampt model under the assumption of stratification, the unbalanced thrust method is derived to efficiently predict the landslide thrust force triggered by rainfall. Then, the Pasternak two-parameter foundation model is employed for the mechanical response of gas pipelines due to the landslide thrust force considering the influence of joints and gas transmission pressure. The accuracy of the presented analytical solution is verified by comparisons with in-situ and model test observed data. It is revealed that the presented solution can provide a prediction of deformation for pipelines induced by landslides in good agreements. Finally, the parametric analyses are performed for the safety assessment of gas pipelines, including amount and rotational stiffness of pipeline joint, saturated permeability coefficient and rainfall intensity.