Mechanical Behavior Analysis of Suspended Pipelines Caused by Ground Subsidence

Long-distance pipelines are prone to suspend due to geological disasters, and large deformation may occur under gravity or other loads. In this study, mechanical behavior of a suspended pipeline caused by ground subsidence was investigated. Effects of suspended length, pipeline diameter, wall thickness, internal pressure, oil weight, and surrounding soil on the suspended pipeline were studied. The results show that the maximum von Mises stress appears on the upper surface of the suspended pipeline’s end. There is a stress concentration on the pipeline’s lower surface, which is in contact with the soil. The von Mises stress increases with the suspended length increases. At the end of the pipeline, the strain on the upper surface is tensile strain, while it on the lower surface is compressive strain. In the middle of the pipeline, the strain on both upper and lower surfaces are tensile strains. The maximum plastic strain only appears on the upper surface of the pipeline end. As the pipeline diameter increases, the von Mises stress and displacement decrease, but the plastic strain increases. For increasing wall thickness, the von Mises stress is approximately constant, but the plastic strain decreases. The von Mises stress of the pipeline increases with increasing of internal pressure and oil weight. When the stratum around the buried pipeline is rock, there is a stress concentration.