A Semi-Analytical Solution for Steady Infiltration in Unsaturated Fractured Rock

Journal Article · Tue Dec 19 04:00:00 EST 2000 · Water Resources Research

OSTI ID:772053

HO, CLIFFORD K ^[1]

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1. Sandia National Laboratories

A semi-analytical solution is developed for one-dimensional steady infiltration in unsaturated fractured rock. The differential form of the mass conservation equation is integrated to yield an analytical expression relating elevation to a function of capillary pressure and relative permeability of the fracture and rock matrix. Constitutive relationships for unsaturated flow in this analysis are taken from van Genuchten [1980] and Mualem [1976], but alternative relations can also be implemented in the integral solution. Expressions are presented for the liquid saturations and pore velocities in the fracture, matrix, and effective continuum materials as a function of capillary pressure and elevation. Results of the analytical solution are applied to examples of infiltration in fractured rock consisting of both homogeneous and composite (layered) domains. The analytical results are also compared to numerical simulations to demonstrate the use of the analytical solution as a benchmarking tool to address computational issues such as grid refinement.

• Research Organization: Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 772053
• Report Number(s): SAND2000-3190J
• Journal Information: Water Resources Research, Journal Name: Water Resources Research
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ANALYTICAL SOLUTION
FRACTURED RESERVOIRS
GEOLOGIC FRACTURES
ONE-DIMENSIONAL CALCULATIONS
PERMEABILITY
WATER INFLUX