Response Analysis For Buried Pipelines Subjected To The Landslide

Buried pipelines as one of part of lifeline are widely used to transport oil, gas, water, waste and so on. The landslide due to earthquake is one of the important factors resulted in damage and destroy of buried pipelines. Therefore, it is necessary to analyze the response of buried pipelines subjected to large ground deformation. Analytical solutions to three kinds of idealized landslide pattern under landslide are derived considering the interaction between soil and pipeline. Meanwhile, finite element models are established to validate the analytical solutions. Some conclusions can be drawn as the following:(1) On the basis of previous studying, a bilinear relationship related to deformation and force is introduced to simulate the soil and pipeline interaction and derive the analytical solutions to buried pipeline subjected to the longitudinal landslide. Compared with FE analysis, some results are obtained. If soil movement is large, the pipe strain is controlled by the length of the landslide. If the length of landslide is large, the pipe strain is dominated by soil movement.(2) Based on the perfectly elastic-plastic constitutive model of soil and the theory of elastic beam, differential equation of buried pipeline under finite width and infinite width transverse landslide is established. Axial strain is composed of bending strain and longitudinal strain due to large transverse deflection of the pipeline. The maximum axial strain is at the position of about 5 meters away from the boundary. The response of pipeline under the 20 m wide slope is almost equal to that of the one under infinitely wide slope. Then plastic pipeline model is proposed to simulate the pipe at the stage of stress strengthening. The effects of the width of landslide, the displacement of soil movement, the diameter of pipe and the buried depth are analyzed through an example.(3) According to the results above, the resultant soil movement with deep circular sliding is decomposed into two components such as parallel and perpendicular to the pipeline. The responses of the pipeline under two soil movement components are calculated respectively, and algebratic sum of maximum strain under each of component is defined as the total peak axial strain of the buried pipeline.The problems and future studying are suggested in the end of the paper.