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2. Pre - Engineer Research and Development Center (ERDC)
3. Structures Laboratory - (4/16/1978 - 2/22/2001)
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5. Contract Report

Title:	An implicit finite difference formulation for treating multiphase flow in wet porous soils
Authors:	Hassig, Paul J.
Keywords:	Consolidation Effective stress Ground motion Implicit finite difference Multiphase constitutive model Multiphase flow Pore pressure Wet porous soils Soil physics Soil mechanics
Publisher:	Structures Laboratory (U.S.)
Series/Report no.:	Contract Report;SL-88-2
Abstract:	Abstract: A one-dimensional (1-D) implicit multiphase finite difference formulation which calculates the relative flow and dynamic stress behavior in wet porous soils has been developed and incorporated into a computer code called CRIME. Various 1-D test cases are presented which demonstrate the ability of CRIME to efficiently calculate to very late times with time steps much larger (factors > 1000) than permitted by standard explicit techniques. In particular, the loading and subsequent consolidation of a realistic layered geology of varying saturation has been successfully simulated. The basic approach is to characterize the geologic materials in terms of both solid (soil lattice) and pore-fluid properties. A variety of constitutive models can be used to describe the effective stress behavior of the soil lattice (e.g., linear-elastic, WES cap-type elastic-plastic, etc.). The pore-fluid properties are those of water and/or air with separate hydrodynamic equations of state (EOS) for each. In the case of partially saturated soils, a pressure equilibrium condition is used for the water-air mixture EOS in the soil pores. The relative flow of pore-fluid through the soil lattice is governed by internal "drag" interaction forces which reduce to Darcy's Law for the special case of steady flow. The soil permeability, the pore-fluid pressure and effective stress gradients, and the pore-fluid viscosity all determine the relative flow velocity.
URI:	http://hdl.handle.net/11681/20481
Appears in Collections:	Contract Report