Three-Dimensional Modelling of Non-Linear Wave-Induced Seabed Response around Offshore Open-Ended Pile

This paper analyses the fluid–seabed–structure interactions (FSSI) around the open-ended pile by applying the in-house solver established on the open-source Computational Fluid Dynamics (CFD) platform. The Reynolds-averaged Navier–Stokes (RANS) equations are solved to simulate the hydrodynamic interactions between waves and open-ended piles. Biot’s poro-elastic theory (quasi-static model) is used to reproduce the wave-induced seabed responses. The parameter analysis indicates that the wave period, degree of saturation of seabed and pile diameter have a great influence on the development of the transient seabed liquefaction depth around the pile. In addition, the distribution of the pore water pressure vs soil depth in the inner zone of the pile presents a “V” shape rotated 90 degrees counterclockwise.

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Numerical Study on Effects of the Embedded Monopile Foundation on Local Wave-Induced Porous Seabed Response

Mathematical Problems in Engineering ◽

10.1155/2015/184621 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Chi Zhang ◽

Qingyang Zhang ◽

Zaitian Wu ◽

Jisheng Zhang ◽

Titi Sui ◽

...

Keyword(s):

Pore Water ◽

Pore Water Pressure ◽

Numerical Study ◽

Water Pressure ◽

Three Dimensional ◽

Navier Stokes ◽

Stokes Wave ◽

Local Concentration ◽

Soil Stress ◽

Local Wave

Effects of the embedded monopile foundation on the local distributions of pore water pressure, soil stresses, and liquefaction are investigated in this study using a three-dimensional integrated numerical model. The model is based on a Reynolds-Averaged Navier-Stokes wave module and a fully dynamic poroelastic seabed module and has been validated with the analytical solution and experimental data. Results show that, compared to the situation without an embedded foundation, the embedded monopile foundation increases and decreases the maximum pore water pressure in the seabed around and below the foundation, respectively. The embedded monopile foundation also significantly modifies the distributions of the maximum effective soil stress around the foundation and causes a local concentration of soil stress below the two lower corners of foundation. A parametric study reveals that the effects of embedded monopile foundation on pore water pressure increase as the degrees of saturation and soil permeability decrease. The embedded monopile foundation tends to decrease the liquefaction depth around the structure, and this effect is relatively more obvious for greater degrees of saturation, greater soil permeabilities, and smaller wave heights.

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Dynamic Seabed Response Around Wind Turbine Foundation: Donghai Offshore Wind Farm China

Volume 6: Polar and Arctic Sciences and Technology; Offshore Geotechnics; Petroleum Technology Symposium ◽

10.1115/omae2013-10221 ◽

2013 ◽

Author(s):

K. T. Chang ◽

D.-S. Jeng

Keyword(s):

Pore Pressure ◽

Wind Farm ◽

Stokes Equations ◽

Three Dimensional ◽

Energy System ◽

Offshore Wind ◽

Degree Of Saturation ◽

Navier Stokes ◽

Offshore Wind Farm ◽

Wave Induced

Donghai offshore wind farm, the first and largest commercial operating offshore wind energy system in China, adopted a novel foundation–high-rising structure foundation. In this paper, a three-dimensional porous model, based on Reynolds-Averaged Navier-Stokes equations and Biot’s poro-elastic theory, was developed by integrating 3D wave and seabed models to simulate wave-induced seabed response around the high-rising structure foundation. Then, a parametric study for the wave and seabed characteristics on the foundation stability was conducted. The numerical results concluded from the numerical analysis were as follows: (i) the existence of structure had a significant effect on the wave transformations and the distributions of wave-induced pore pressures; (ii) the magnitude of wave-induced pore pressure increased as wave height or wave period increased; (iii) the dissipation rate of pore pressure increased as the degree of saturation decreased.

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Three-Dimensional Numerical Investigation on the Seepage Field and Stability of Soil Slope Subjected to Snowmelt Infiltration

Water ◽

10.3390/w13192729 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2729

Author(s):

Shengyi Cong ◽

Liang Tang ◽

Xianzhang Ling ◽

Wenqiang Xing ◽

Lin Geng ◽

...

Keyword(s):

High Speed ◽

Slope Failure ◽

Pore Water Pressure ◽

Water Pressure ◽

Three Dimensional ◽

Ground Surface ◽

Degree Of Saturation ◽

Seepage Field ◽

High Speed Railway ◽

Cutting Slope

Cutting slope failures occur frequently along the high-speed railways in Northeast China during the construction due to snowmelt infiltration. This study addresses this issue by applying a three-dimensional numerical model. The influence of the depth of accumulated snow (ds), daily temperature variation (ΔT), and freeze-thaw (F-T) cycles on the seepage field and stability of cutting slopes is discussed. The results demonstrate that water seepage due to snowmelt infiltration primarily extends through the ground surface by about 10 m. The deep-seated instability is likely to occur under a prolonged and highly accumulated infiltration, while shallow failure is associated with intense, short-duration snowmelt infiltration. The maximum degree of saturation (Sr) and pore-water pressure (PWP) values are observed at the slope toe. Increasing ds and ΔT increase the Sr and PWP due to snowmelt infiltration and thereby decreases cutting slope stability. Compared to the ds and ΔT, the F-T cycle is more likely to cause slope failure. In addition, the F-T cycle also induces the reduction of soil strength and the crack propagation. Overall, the conducted study provided useful help toward the process of safer design for cutting slope along the high-speed railway in seasonally cold regions.

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The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽

10.3390/geosciences11020073 ◽

2021 ◽

Vol 11 (2) ◽

pp. 73

Author(s):

Panagiotis Sitarenios ◽

Francesca Casini

Keyword(s):

Analytical Solution ◽

Slope Stability ◽

Slope Failure ◽

Failure Modes ◽

Pore Water Pressure ◽

Limit Equilibrium ◽

Water Pressure ◽

Three Dimensional ◽

Stability Limit ◽

Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

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Three‐Dimensional Numerical Investigation of Pore Water Pressure and Deformation of Pumped Aquifer Systems

Ground Water ◽

10.1111/gwat.12909 ◽

2019 ◽

Vol 58 (2) ◽

pp. 278-290 ◽

Cited By ~ 2

Author(s):

Yun Zhang ◽

Xuexin Yan ◽

Tianliang Yang ◽

Jichun Wu ◽

Jianzhong Wu

Keyword(s):

Numerical Investigation ◽

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Three Dimensional ◽

Aquifer Systems

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Wave-Induced Pore Water Pressure Accumulation in Marine Soils

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.3257133 ◽

1989 ◽

Vol 111 (1) ◽

pp. 1-11 ◽

Cited By ~ 55

Author(s):

W. G. McDougal ◽

Y. T. Tsai ◽

P. L-F. Liu ◽

E. C. Clukey

Keyword(s):

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Wave Induced

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Numerical simulation of three-dimensional velocity fields in pressurized and non-pressurized Nye channels

Annals of Glaciology ◽

10.3189/172756403781815609 ◽

2003 ◽

Vol 37 ◽

pp. 281-285 ◽

Cited By ~ 3

Author(s):

Paul D. Bates ◽

Martin J. Siegert ◽

Victoria Lee ◽

Bryn P. Hubbard ◽

Peter W. Nienow

Keyword(s):

Water Flow ◽

Water Pressure ◽

Three Dimensional ◽

Experimental Manipulation ◽

Navier Stokes ◽

Ice Dynamics ◽

Theoretical Understanding ◽

Water Flow Velocity ◽

Hydraulic Behaviour ◽

Strong Control

AbstractChannels incised into bedrock, or Nye channels, often form an important component of subglacial drainage at temperate glaciers, and their structure exerts control over patterns and rates of (a) channel erosion, (b) water flow-velocity and (c) water pressure. The latter, in turn, exerts a strong control over basal traction and, thus, ice dynamics. In order to investigate these controls, it is necessary to quantify detailed flow processes in subglacial Nye channels. However, it is effectively impossible to acquire such measurements from fully pressurized, subglacial channels. To solve this problem, we here apply a three-dimensional, finite-volume solution of the Reynolds averaged Navier– Stokes (RANS) equations with a one-equation mixing-length turbulence closure to simulate flow in a 3 m long section of an active Nye channel located in the immediate foreground of Glacier de Tsanfleuron, Switzerland. Numerical model output permits high-resolution visualization of water flow through the channel reach, and enables evaluation of the experimental manipulation of the pressure field adopted across the overlying ice lid. This yields an increased theoretical understanding of the hydraulic behaviour of Nye channels, and, in the future, of their effect on glacier drainage, geomorphology and ice dynamics.

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PROPAGATION OF PORE WATER PRESSURE IN SAND LAYER OF HIGH DEGREE OF SATURATION

Proceedings of the Japan Society of Civil Engineers ◽

10.2208/jscej1969.1975.236_81 ◽

1975 ◽

Vol 1975 (236) ◽

pp. 81-92 ◽

Cited By ~ 1

Author(s):

Reisaku INOUE

Keyword(s):

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Degree Of Saturation ◽

Sand Layer ◽

High Degree

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Analyses of groundwater flow and plant evapotranspiration in a vegetated soil slope

Canadian Geotechnical Journal ◽

10.1139/cgj-2013-0148 ◽

2013 ◽

Vol 50 (12) ◽

pp. 1204-1218 ◽

Cited By ~ 43

Author(s):

A.K. Leung ◽

C.W.W. Ng

Keyword(s):

Groundwater Flow ◽

Pore Water Pressure ◽

Water Pressure ◽

Three Dimensional ◽

Root Water Uptake ◽

Dry Season ◽

Climatic Data ◽

Wet Season ◽

Soil Slopes ◽

Transient Seepage

Understanding seasonal hydrogeological responses of vegetated soil slopes is vital to slope stability because pore-water pressure (PWP) varies from positive values upon rainfall in wet seasons to negative values upon plant evapotranspiration (ET) in dry seasons. There are, however, few case histories that report seasonal performance of vegetated soil slopes. In this study, a vegetated slope situated in Hong Kong was instrumented to analyse (i) groundwater flow during rainfall in the wet season and (ii) effects of plant ET on PWP in the dry season. Two- and three-dimensional anisotropic transient seepage analyses are conducted to identify groundwater flow mechanism(s) during a heavy rainstorm. Through water and energy balance calculations, measured plant-induced suction is interpreted with plant characteristic and climatic data. During the rainstorm, substantial recharge of the groundwater table was recorded, likely due to preferential water flow along relict joints and three-dimensional cross-slope groundwater flow. During the dry season, the peak suction induced by plant ET is up to 200 kPa and the depth of influence is shallower than 200% of the root depth. For the range of suctions monitored, root-water uptake is revealed to have been restricted by suction not very significantly and was driven mainly by the climatic variation.

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