Research On Failures Of Pipeline Under Geological Disaster

In the project of energy transportation from the west to the east, pipelines cross the loess altiplano. Because of its special land conditions, there are a lot of disasters, such as collapse, gulch and landslide. They occur frequently. They cause pipeline to be distorted or destroyed, and they will bring a lot of loss. So it is very important to study the of pipelines.The paper studies pipelines behaviors by geomechanics , soil and solid mechanics. And compute the created model by the way of FEM. And results are:(1) analyze the force and distortion on pipeline under collapse and gulch in theory. On the base of beam deformation, analyze the bending moment and deformation of pipeline with frusta and without frusta. Calculate a true problem, contrast the differences between pipeline with frusta and one without frusta , draw some conclusions.(2) on the base of Winkler model, compute the anti-forces of pipeline without frusta, considering the loess cohesion. Compute the distortion and force of pipeline under different length of collapse. And get the stress field and the greatest Mises stress and its location.(3) on the base of Ranken theory, analyze the soil-line model. In the model, they are considered, soil effect up and under line, line weight, gas pressure and its weight. By the way of FEM, we get the stress field and he greatest Mises stress and its location under different landslide conditions.(4) simulate the buckling condition of pipeline by pre- disfigure. Compute the force in pipeline under inner pressure and coaxial forces. And get the conclusion that there is abrupt change of stress in the defect location. So it's the position easy to be buckling.