Mechanical Responses of Curved Pipe Corssing Mining Subsidence Area

Abstract

The deformation of the curved pipeline in the mining subsidence area may be different from the ordinary straight pipeline. Curved pipeline is prone to large deformation in the mining subsidence area, which may cause pipeline accidents. Thus, it is of great importance to investigate the mechanical properties of the curved pipeline in the mining subsidence area. The numerical simulation model of pipeline-soil coupling was established by the nonlinear numerical simulation method in this study. The mechanical responses of the curved pipeline under the stratum settlement, collapse, and suspension are investigated. The results show that when the settlement area is located below the curved section of the pipeline, the maximum stress is in the middle of the curved section, there will be more high stress areas when the curved angle larger. When the settlement area is located below the half curved part and half straight part of the pipeline, the high stress area of the pipeline is located at the end of the curved section. The stress and displacement increase with the increase of angle in both cases, but the maximum stress in pipeline is not reached the yield strength. Whether the collapse interface is located in the middle of the curved section or at both ends of the curved section, the high stress area occurs near the collapse interface, the large curved angle of the pipeline is prone to generate large high stress area and produce large plastic strain, and the cross section of the pipeline has a tendency to squeeze to one side. For the suspended curved pipeline, the stress, plastic strain and displacement of the suspended curved pipeline increase with the increase of suspended length and curved angle.

Keywords

• curved pipeline
• numerical simulation
• mining subsidence area
• stress
• strain