WANG Teng, WU Rui. Study of vertical penetration resistance of seabed pipelines in cohesive soil[J]. 2019, 40(3): 871-878.DOI: 10.16285/j.rsm.2017.1797.
Study of vertical penetration resistance of seabed pipelines in cohesive soil
The on-bottom stability of deepwater seabed pipelines is affected by the vertical penetration depth and resistance. In this study
the coupled Eulerian-Lagrangian approach(CEL) was used to simulate the vertical penetration of pipelines in cohesive soil
and the effects of strain rate behavior and strain softening on bearing capacity of pipelines were studied by subprogram VUSDFLD.The resistance provided by the heaved-soil on both sides of the pipeline during the penetration process was analyzed and the sensitivity analysis of the resistance was implemented
then a surface heave capacity factor was proposed. Results indicated that bearing capacity factor of the pipeline increases significantly with the increase of strain rate parameter. A high sensitivity of soil leads to a fast softening rate of soil and a low bearing capacity factor of pipeline. The surface heave capacity factor mainly depends on the submerged weight of the soil. Moreover
the greater the penetration depth
the more obvious the effect of the submerged weight of soil on the bearing capacity of surface heave. An expression describring the surface heave capacity is developed by fitting the numerical results.