地面堆载对高后果区埋地管道承载能力的影响

Influence of Surface Surcharge on Bearing Capacity of Buried Pipeline in High Consequence Area

为了分析地面堆载对高后果区埋地管道承载能力的影响,采用ANSYS workbench有限元软件建立了堆载-土壤-管道应力状态分析三维模型,采用堆载体直接加载在地基土壤上,分析管道在堆载下的承载能力响应,采用理论计算验证了模型的可行性,分别探讨了堆载高度、管道埋深、堆载距离、管径、壁厚和土壤泊松比因素对管道承载能力的影响。结果表明,堆载下管道应力最大出现在堆载下方,并且向管道两边递减,堆载范围内的承载能力明显减弱。堆载高度和堆载距离对管道承载能力的影响最大,堆载距离的微小改变可以明显提高管道的承载能力,堆载高度的增加同时又导致管道承载能力减弱,通过堆载高度和堆载距离的变化规律可以用来判断,在管道极限承载能力范围内,不同堆载位置下的极限堆载高度。在一定堆载高度下,管道存在一个临界埋深,此时管道承载能力最大。管径、壁厚和土壤性质对管道承载能力有影响但较小。研究结果可以为判断高后果区埋地管道占压下安全状态提供指导。

In order to analyze the influence of ground surcharge on the bearing capacity of buried pipeline in high consequence area,the three-dimensional model of surcharge soil pipeline stress state analysis was established by using ANSYS workbench finite element software.The surcharge carrier was directly loaded on the foundation soil to analyze the bearing capacity response of pipeline under surcharge.The feasibility of the model was verified by theoretical calculation.The influence of the surcharge height,pipeline buried depth,stacking distance,pipe diameter,wall thickness and soil Poisson's ratio on pipeline bearing capacity discussed.The results show that the maximum stress of the pipeline under the surcharge appears below the surcharge and decreases to both sides of the pipeline,and the bearing capacity within the surcharge range is obviously weakened.The stacking height and stacking distance have the greatest impact on the bearing capacity of the pipeline.The slight change of stacking distance can significantly improve the bearing capacity of the pipeline.The increase of stacking height also leads to the weakening of the bearing capacity of the pipeline.The change law of stacking height and stacking distance can be used to judge that within the range of the ultimate bearing capacity of the pipeline,Limit stacking height at different stacking positions.At a certain stacking height,there is a critical buried depth of the pipeline,and the bearing capacity of the pipeline is the largest.Pipe diameter,wall thickness and soil properties have little influence on the bearing capacity of the pipeline.The research results can provide guidance for judging the safety state of buried pipeline under pressure in high consequence area.