浅埋PVC管道穿越挖填方场地时受力状态研究

The study of positive buried pipeline's strained condition crossing the transition zone of high embankment

以延安新区黄土沟壑高填方工程中的PVC输水管道为原型,通过1:2物理模型试验,预设沉降底板模拟高填方的工后沉降过程,对比不同接口布设位置的管道在穿越填挖结合场地时的受力变形过程,采集管道变形、应变和管土接触压力等数据,对比不同接口位置对管道的影响。研究表明:浅埋PVC管道受负土拱效应影响明显,深层沉降量超过6 mm后填方场地中管道底部与土体出现脱空,管道竖向变形明显。对比2根管道的内力曲线发现,填挖结合部位中管道的内力受支座转角与竖向位移控制,管道接口的不良影响在这一阶段开始显现,建议在填挖结合区和工后沉降量大的填方场地采用柔性接口设计。

This paper took the PVC drainage pipeline in Yan'an District of loess gully high embankment engineering as the test's prototype. By making a 1:2 physical model test, the combination of filling and excavation site of shallow buried PVC pipes in the post construction settlement was simulated during the stress and the deformation process. The deformation of pipeline, pipe soil contact pressure and strain data were obtained. Studies show that when the deep ground subsidence quantity is greater than 6 mm, pipe in various parts of the stress state of differentiation and pipeline interface for the adverse effects at this stage starts to appear. The pipeline interface is not recommended layout in cut fill transition zone and the middle of high fill.