Abstract

Soil restraints associated with relative soil-pipe movements is an important consideration for stability assessment of buried pipelines. This paper investigates the effects of pipe surface roughness, inclination angle within the horizontal-vertical plane and embedment ratio on the development of soil restraint on shallow pipes in sand. In total, 24 model tests were performed, using an image-based non-destructive soil deformation measurement technique. The failure and deformation mechanisms during oblique pipe movements were discussed based on image analysis results. The test results were then used to verify the Finite Element Limit Analysis (FELA) model, by which a parametric study on the peak soil restraint in a wider range of soil and pipe parameters was carried out. It is shown that the peak soil restraint increased with greater pipe embedment ratio, inclination angle of movements to the vertical and sand-pipe interface frictional strength because of a larger range of soil was mobilised, and the effects of these factors reduced at deeper depths. To account for the effects of oblique movements on the peak resistance received by pipelines in sand, an analytical relationship is presented and examined based on the test and simulation results.

摘要

与土壤-管道相对运动相关的土壤约束是埋地管道稳定性评估的重要考虑因素。本文研究了管道表面粗糙度、水平-垂直面内的倾角和埋置比对沙中浅管道土壤约束发展的影响。使用基于图像的非破坏性土壤变形测量技术，总共进行了 24 次模型测试。基于图像分析结果讨论了斜管运动过程中的破坏和变形机制。然后将测试结果用于验证有限元极限分析 (FELA) 模型，通过该模型在更广泛的土壤和管道参数范围内对峰值土壤约束进行参数研究。结果表明，随着管道埋置率的增大，最大的土壤约束力增加，垂直运动的倾角和沙管界面摩擦强度由于更大范围的土壤被动员而增加，并且这些因素的影响在更深的深度减小。为了说明斜向运动对沙中管道接收的峰值阻力的影响，基于测试和模拟结果提出并检验了一种分析关系。