中文摘要：

地层沉陷致埋地HDPE管道事故频发,主要原因之一是地层沉陷过程中所诱发的管道附加应力和变形剧增,从而导致管道破坏。已有研究成果大多集中于固定尺寸沉陷区域管道与周围土体力学特性的分析,尚无相关理论预测沉陷发展过程中管道力学响应特征变化规律。利用自制室内足尺大型模型试验系统,以粗砂为管道开挖沟槽回填料,通过调整模型箱底板的下沉模拟地层沉陷形成过程,研究埋地HDPE双壁波纹管道的受力变形特性及其上覆回填料土体的沉降分布规律。试验结果表明：1地层沉陷过程中HDPE管道的竖向变形符合修正高斯分布曲线;2随着土体沉陷的发展,管道顶部土压力随之增大,且试验管道顶部的土拱率由0.7增大到2.05,呈现出明显负土拱效应;3对于相同抗弯刚度管道,土体沉陷变形所致管道附加变形随管道上覆土层厚度的减小而减小;4随着管道抗弯刚度增加,埋地管道对于土体的沉降抑制作用愈加明显。

英文摘要：

Failure of buried high-density polyethylene（HDPE） pipes caused by land subsidence is often encountered in the engineering practice. The main reason is the additional stress and strain on the buried HDPE pipes induced by the land subsidence. Most of the previous studies focus on the mechanical responses of HDPE pipes to a mobilized zone in the ground with a specific size. However, no analytical methods are available to evaluate the pipe responses during the process of ground movement. In this study, coarse sand is filled in a custom-made pipe-soil interaction testing system, and the lowering of the adjustable bottom of the test box is used to simulate the effect of land subsidence. During the test process, the earth pressure, deformation of HDPE pipes and subsurface settlement above the pipe are measured. The test results demonstrate that（1） The vertical deflection distribution of HDPE pipes in the longitudinal direction agrees well with the modified Gaussian curve;（2） The vertical earth pressure on the pipe crown increases with the lowering of the bottom plates, and the soil arching ratio at the pipe crown increases from 0.7 to 2.05, which indicates that negative soil arching occurs above the pipe during the ground movement;（3） The effect of the ground movement on the deformation of HDPE pipes gradually decreases with the decrease of the thickness of soil cover;（4） The magnitude of the subsurface settlement above the pipe is limited more significantly when the bending stiffness of the pipe increases.