Accession Number : ADA195333

Title :   An Implicit Finite Difference Formulation for Treating Multiphase Flow in Wet Porous Soils.

Descriptive Note : Final rept. Jun-Oct 87,

Corporate Author : CALIFORNIA RESEARCH AND TECHNOLOGY INC CHATSWORTH

Personal Author(s) : Hassig, Paul J

PDF Url : ADA195333

Report Date : Apr 1988

Pagination or Media Count : 89

Abstract : A one dimensional 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. 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. 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. Soil permeability, the pore-fluid pressure and effective stress gradients, and the pore-fluid viscosity all determine the relative flow velocity.

Descriptors :   *MULTIPHASE FLOW, *SOIL MECHANICS, COMPUTER PROGRAMS, DYNAMIC RESPONSE, EQUATIONS OF STATE, EQUILIBRIUM(GENERAL), FINITE DIFFERENCE THEORY, FLOW, FLOW RATE, FORMULAS(MATHEMATICS), GEOLOGY, GRADIENTS, HYDRODYNAMICS, LAYERS, MOISTURE, PERMEABILITY, PHASE, POROUS MATERIALS, PRESSURE, SATURATION, SOILS, STRESSES, VELOCITY, WATER, SOIL DYNAMICS

Subject Categories : Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE