采坑区冲沟演变影响下管道埋深预测

Prediction of Buried Depth of Pipeline under the Influence of Gully Evolution in Sand Pit Area

管道埋深是水毁灾害风险评价、防治决策的关键指标之一。基于洪积扇采坑区冲沟发育特征、几何形态及其对油气管道的影响方式,将冲沟演变过程简化为溯源侵蚀和沟床回淤两个阶段,在此基础上构建管道埋深预测模型,利用15处水毁点管道埋深实测值对模型预测值进行验证。结果表明:偏差小于15%的比例达73%,预测结果基本可信。模型中管道埋深与冲刷比降、回淤比降、设计埋深、水平距离、沉积厚度呈线性正相关,与采坑深度、原始坡面坡降、采坑边坡坡降呈负相关。该模型能快速预测出不同沟床比降下的管道埋深,可为采坑区穿越段管道风险评价、灾害防治、选线提供技术支撑。

The buried depth of pipeline is one of the key indexes for risk assessment and decision-making of prevention and control for water damage.Based on the development characteristics,and geometric shape of gullies,and the influence of gullies on oil and gas pipelines in sand pit area of pluvial fan,the evolution process of gullies was simplified into two stages,including retrogressive erosion and gully bed siltation.On this basis,the model for predicting the buried depth of pipeline was established.The predicted values were further verified by the measured buried depth of pipeline at 15 water damage points.The results show that the proportion of deviations less than 15%is 73%,which indicated that the predicted results are basically reliable.In addition,the buried depth of pipeline is positively correlated with scour gradient,siltation gradient,design buried depth,horizontal distance and deposition thickness.It is negatively correlated with pit depth,original slope,and pit slope,respectively.The model can quickly predict the buried depth of pipeline under different gully bed gradient,and it can provide science and technology support for risk assessment,disaster prevention,and route selection of pipeline in sand pit area.