推移式土质滑坡下输气管道力学响应及路由优化分析

Mechanical response and route optimization analysis of gas pipelineunder thrust-type soil landslide

为分析土质滑坡下管土作用对横穿敷设的输气管道所带来的影响,探讨滑坡影响区内管道路由选取,本文基于光滑粒子流体动力学与有限单元耦合法(SPH-FEM),构建滑坡下管道受力分析模型,从设计角度出发,综合考虑管道敷设位置,探讨管道壁厚、埋深等因素影响,分析土体大变形下管道受力变形特征。结果表明:针对推移式滑坡,管道敷设于滑体内时,位于滑体前缘处管道所产生的应力、位移较小,而后缘处管道更易发生损坏,当提高管道壁厚时,可有效提高管道承载能力,但对于埋深的增加,管道有效屈服应变呈现先增加而后减小的趋势;管道敷设于滑体外时,位于滑坡前缘管道产生应力小于后缘处管道,且呈现出不同应力状态,均满足运行安全,同时壁厚的增加可降低管道应力。所得结论可为设计阶段滑坡区管道路由优化提供建议,具有一定的工程意义与应用价值。

In order to analyze the effect of pipeline-soil action on the gas pipeline crossing under the soil landslide,the pipeline route selection in the landslide affected area was discussed.Based on smooth particle hydrodynamics and finite element coupling method(SPH-FEM),the force analysis model of pipeline under landslide was established.From the design point of view,the position of pipeline laying was comprehensively considered,the influence of pipeline wall thickness,buried depth and other factors was discussed,and the force deformation characteristics of pipeline under large soil deformation were analyzed.Based on the results,some suggestions are provided for pipeline routing optimization in landslide area.Results show that for the thrust-type landslide,when the pipeline is laid in the sliding mass,the stress and displacement of the pipeline at the leading edge of the sliding mass are small,and the damage of the pipeline at the posterior border is more likely.When the thickness of the pipeline wall is increased,the bearing capacity of the pipeline can be effectively improved,but with the increase of the buried depth,the effective yield strain of the pipeline increases first and then decreases.When the pipeline is laid outside the landslide,the stress of the pipeline located at the leading edge of the landslide is less than that at the posterior border,and it presents different stress states,which meet the safety of operation.At the same time,the increase of wall thickness can reduce the stress of the pipeline.The conclusions can provide suggestions for pipeline routing optimization in landslide area in the design stage,which has certain engineering significance and application value.