Investigation of liquefaction‐induced lateral spreading of gently sloping grounds using a variable permeability model

2021 ◽  
Author(s):  
Mahmood Malekmakan ◽  
Hadi Shahir ◽  
Peyman Ayoubi
Keyword(s):  
Lateral Spreading ◽  
Permeability Model ◽  
Variable Permeability

scholarly journals Variable-Permeability Well-Testing Models and Pressure Response in Low-Permeability Reservoirs with non-Darcy Flow

2016 ◽  
Vol 20 (1) ◽  
pp. 1-6
Author(s):  
Naichao Feng ◽  
Shiqing Cheng ◽  
Weixing Lan ◽  
Guoquan Mu ◽  
Yao Peng ◽  
...  
Keyword(s):  
Numerical Solutions ◽  
Boundary Effect ◽  
Geometric Mean ◽  
Well Testing ◽  
Pressure Derivative ◽  
Permeability Model ◽  
Type Curves ◽  
Variable Permeability ◽  
The One ◽  
Low Permeability Reservoirs

<p>This paper proposes the concept of variable-permeability effect and sets up the one-dimensional and two-dimensional non-Darcy well testing models. The finite difference algorithm is employed to solve the differential equations of the variable-permeability model, and the non-convergence of the numerical solutions is solved by using the geometric mean of permeability. The type curves of pressure and pressure derivative with variable-permeability effect are obtained, and sensitivity analysis is conducted. The results show that the type curves upturn in the middle and late sections, and the curves turn more upward with the severer of the variable-permeability effect. The severer the non-Darcy effect is, the less obviously the curve upturns caused by boundary effect. Furthermore, the boundary effect is increased by increasing the number of impermeable boundaries or decreasing the distance between the well and boundary.</p>

scholarly journals Flow of a Fluid with Pressure-Dependent Viscosity through Variable Permeability Porous Layer

2021 ◽  
Vol 16 ◽  
pp. 204-212
Author(s):  
M. S. Abu Zaytoon ◽  
Yiyun (Lisa) Xiao ◽  
M. H. Hamdan
Keyword(s):  
Drag Coefficient ◽  
Flow Velocity ◽  
Control Parameter ◽  
Flow Model ◽  
Flow Characteristics ◽  
Permeability Model ◽  
Proportionality Constant ◽  
Variable Permeability ◽  
Pressure Dependent Viscosity ◽  
Dependent Viscosity

In this work, we consider flow of a fluid with pressure-dependent viscosity down an inclined porous plane with variable permeability that is incorporated in the pressure-dependent drag coefficient. We provide a solution to a recently developed flow model, and study the effects of flow and domain parameters (viscosity control parameter, permeability proportionality constant, and angle of inclination) on the flow characteristics. Suitability of a variable permeability model that considers permeability proportional to the flow velocity is investigated. Results show that large values of the permeability proportionality constant have little or no effects on flow characteristics.

scholarly journals Evaluation of variable permeability model in simulation of seismic behavior of uniform level and gently sloping sand layers

2020 ◽  
Vol 24 (3) ◽  
pp. 335-343
Author(s):  
Ali Ghassemi ◽  
S. Seyfi ◽  
H. Shahir
Keyword(s):  
Cyclic Loading ◽  
Numerical Model ◽  
Time History ◽  
Cyclic Behavior ◽  
Saturated Sand ◽  
Permeability Model ◽  
Geotechnical Centrifuge ◽  
Surface Plasticity ◽  
Variable Permeability ◽  
Centrifuge Tests

In this study, a fully coupled dynamic finite element model was employed for numerical simulation of the response of level to gently sloping saturated sand layers subjected to cyclic loading. This model utilized a critical state two-surface-plasticity constitutive model to simulate the cyclic behavior of sandy soil. Moreover, a recently proposed variable permeability function was implemented in the numerical model to reflect the effects of soil permeability variations during the liquefaction phenomenon. The numerical model was validated by simulating a number of well-documented geotechnical centrifuge tests with different relative density of sand, base acceleration time history, and surface slope of the sand layer. The obtained results confirmed that the developed model was capable of simulating the behavior of saturated sand under cyclic loading for both level and gently sloping conditions.

Development of Experimental P-Y Curves from Centrifuge Tests for Piles Subjected to Static Loading and Liquefaction-Induced Lateral Spreading

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Milad Souri
Keyword(s):  
Static Loading ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Pressure Ratio ◽  
Lateral Spreading ◽  
American Petroleum Institute ◽  
Unique Contribution ◽  
Pile Groups ◽  
Centrifuge Tests ◽  
Centrifuge Models

The results of five centrifuge models were used to evaluate the response of pile-supported wharves subjected to inertial and liquefaction-induced lateral spreading loads. The centrifuge models contained pile groups that were embedded in rockfill dikes over layers of loose to dense sand and were shaken by a series of ground motions. The p-y curves were back-calculated for both dynamic and static loading from centrifuge data and were compared against commonly used American Petroleum Institute p-y relationships. It was found that liquefaction in loose sand resulted in a significant reduction in ultimate soil resistance. It was also found that incorporating p-multipliers that are proportional to the pore water pressure ratio in granular materials is adequate for estimating pile demands in pseudo-static analysis. The unique contribution of this study is that the piles in these tests were subjected to combined effects of inertial loads from the superstructure and kinematic loads from liquefaction-induced lateral spreading.

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