Three-dimensional poro-elastic integrated model for wave and current-induced oscillatory soil liquefaction around an offshore pipeline

2019

JMSE

Self Cite

The evaluation of the wave-induced seabed response around a buried pipeline has been widely studied. However, the analysis of seabed response around marine structures under the wave and current loadings are still limited. In this paper, an integrated numerical model is proposed to examine the wave and current-induced pore pressure generation, for instance, oscillatory and residual pore pressure, around a buried pipeline. The present wave–current model is based on the Reynolds-Averaged Navier–Stokes (RANS) equation with k - ε turbulence while Biot’s equation is adopted to govern the seabed model. Based on this numerical model, it is found that wave characteristics (i.e., wave period), current velocity and seabed characteristics such as soil permeability, relative density, and shear modulus have a significant effect on the generation of pore pressure around the buried pipeline.

Section: Methodsmentioning

confidence: 99%

Two-Dimensional Numerical Study of Seabed Response around a Buried Pipeline under Wave and Current Loading

Foo

Liao

2019

JMSE

Self Cite

“…Recently, this model was used to study the progressive and nonlinear standing wave-induced liquefaction in a loosely deposited seabed Ye, 2017, 2018). Based on u-p approximation, numerical models have also been developed and applied to cases of pipelines (Duan et al, 2017a;Dunn et al, 2006) and breakwaters (Jeng et al, 2013;Zhang et al, 2012).…”

Section: U-p Approximationmentioning

confidence: 99%

A Numerical Approach to Determine Wave (Current)-Induced Residual Responses in a Layered Seabed

Jeng

Journal of Coastal Research

Liao

et al. 2019

Self Cite

“…The method is simple, which is suitable for the analysis of the oscillatory pore pressure response induced by waves acting on the sandy seabed. The second method is to apply Biot's poro-elastic theory for soil models to describe the pore pressure response [17][18][19][20][21]. Based on Biot's poro-elastic theory, Shen et al [22] first explored the pore-pressure response in the soil around the suction anchor under cyclic loading conditions, but this was limited to the sandy seabed.…”

Section: Introductionmentioning

confidence: 99%

Accumulation of Pore Pressure in a Soft Clay Seabed around a Suction Anchor Subjected to Cyclic Loads

et al. 2019

JMSE

A suction anchor is an appealing anchoring solution for floating production. However, the possible effects of residual pore pressure can be rarely found any report so far in term of the research and design. In this study, the residual pore pressure distribution characteristics around the suction anchor subjected to vertical cyclic loads are investigated in a soft clay seabed, and a three-dimensional damage-dependent bounding surface model is also proposed. This model adopts the combined isotropic-kinematic hardening rule to achieve isotropic hardening and kinematic hardening of the boundary surface. The proposed model is validated against triaxial tests on anisotropically consolidated saturated clays and normally consolidated saturated clays. The analytical results show that the excess pore water pressure accumulates primarily on the outside of the suction anchor, whereas negative pore water pressure mainly on the inside. The maximum values of both sides appear in the lower part of the seabed. According to the distribution characteristics of the residual pore pressure, a perforated anchor is proposed to reduce the accumulation of excess pore water pressure. A comparative study generally shows that the perforated anchor can effectively reduce the accumulation of excess pore water pressure.