深基坑开挖对附近直埋管线影响的数值分析

Numerical Analysis for Influence of Deep Excavation on Adjacent Unprotected Underground Pipelines

城市深基坑开挖引起附近地下管线周围土体发生位移,从而影响管线的正常使用和安全。为研究深基坑开挖对附近直埋管线的影响,采用ANSYS软件建立三维有限元模型。从基坑尺寸,管线材质,埋深,埋距以及管线周围和下卧层土体等六个方面入手,分析了不同因素在深基坑开挖过程中对直埋管线的影响。结果表明:沿基坑长边埋设的管线所受影响较短边大;2倍基坑深度为管线与基坑的最佳距离;此外管线周围土体和自身材质也有一些影响。

In cities,some underground pipelines could not work normally because of the deep excavations,which would make the earth around the pipelines move too much.In order to analyze the displacement influence of deep excavations on adjacent unprotected underground pipelines,the software ANSYS is used to set up the 3-D finite element model,and the affecting factors are studied in six aspects, including the size of excavation,pipelines＇ material,pipelines＇ depth,the distance between the excavations,and the soil mass below and around the pipelines.The analysis results show that the affecting along the long side of deep excavations for the pipelines is larger than that along the short side,and twice depth of deep excavations is the best distance between pipelines and deep excavations,moreover the materials of pipelines and earth around pipelines would also show much influence.