Pipeline–Soil Separation Model for Natural Gas Pipelines Subjected to Parabolic Driving Force

Abstract

In view of the nonuniform landslide driving force in practical cases and the common landslide–pipeline separation phenomenon, a new pipeline–soil separation model under the action of a parabolic landslide driving force is proposed in this paper, and the closed analytical solutions for this model are derived based on elastic foundation theory. Moreover, the case of a long transportation pipeline crossing the Luozhentian landslide was studied using the analytical method, and comparisons between the analytical results and finite-element method (FEM) results are also made to validate the exactitude of the analytical solutions. In addition, the deflection and stress results of the pipeline in different conditions were also compared, and influences of the calculation parameters on pipelines were analyzed. Three conclusions can be drawn: (1) the deflection and stress of the pipeline increase remarkably along with the growth of length of the separation section; (2) the deflection and stress of the pipeline increase along with the growth of |λ|, which reflects the nonuniform degree of the parabolic driving force; (3) the deflection of the pipeline decreases slightly with the growth of the resistance coefficient k of the landslide soil, whereas the stress changes nonmonotonously; and (4) the deflection and stress of the pipeline slightly decrease with the growth of the lengths of pipeline crossing the landslide, and the maximum deflection of pipeline increases with the growth of the proportion Ω.