Physical modeling of the axial pipe-soil interaction for pipeline walking on a sloping sandy seabed

• Published in: Ocean engineering Vol. 178; pp. 20 - 30
• Main Authors: Shi, Yu-Min, Wang, Ning, Gao, Fu-Ping, Qi, Wen-Gang, Wang, Jun-Qin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.04.2019
• Subjects: Physical modeling; Pipeline walking; Pipeline-seabed interaction; Sloping seabed; Physical modeling; Pipeline walking; Pipeline-seabed interaction; Sloping seabed
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2019.02.059

Axial pipe-soil interaction is crucial for the prediction of pipeline walking, especially on a sloping seabed. In this study, a mechanical-actuator facility has been specially designed and utilized to simulate the axial pipe-soil interactions along a sloping sandy seabed. Based on dimensional analyses, an apparent axial anti-sliding coefficient is proposed to describe the anti-sliding capacity for pipeline walking on a sloping seabed under the fully-drained condition. Effects of the pipeline surface roughness, the submerged weight (G) of the pipeline and the slope angle (α) of the seabed on the apparent axial anti-sliding coefficient are investigated experimentally. The experimental results indicate that, for a fixed value of the non-dimensional submerged pipeline weight, both the ultimate anti-sliding capacity and the corresponding mobilization displacement increase with the increase of the slope angle of the seabed. There exist approximately linear correlations between the apparent anti-sliding coefficient and the examined seabed slope angle (−9o≤α≤9o) or the non-dimensional submerged pipeline weight (0.34≤G≤0.81). An expression for the apparent axial anti-sliding coefficient incorporating an updated wedging factor is finally deduced and validated with the present experimental results. This axial pipe-soil interaction model may help assessing the pipeline walking along subsea continental slopes. •A mechanical-actuator facility to simulate the axial pipe-soil interactions along a sloping seabed.•An apparent axial anti-sliding coefficient is proposed to describe pipeline walking on the sloping sandy seabed.•Effects of the surface roughness, the submerged weight of pipelines and the seabed slope angle on axial anti-sliding coefficient.•An expression for the apparent axial anti-sliding coefficient incorporating an updated wedging factor.