Soil restraint on buried pipelines during oblique relative movements in sand: Fid-Bau Portal

Soil restraint on buried pipelines during oblique relative movements in sand

Yue, Hongya / Zhuang, Peizhi / Song, Xiuguang / Song, Yanjie / Wang, Ji-peng

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.