Infiltration of a liquid front in an unsaturated, fractured porous medium

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Water Resources Research; (United States)

DOI:https://doi.org/10.1029/91WR01369· OSTI ID:6127060

Nitao, J J; Buscheck, T A ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

The authors consider liquid infiltrating by gravity flow into a system of parallel, regularly spaced fractures in an unsaturated porous medium. The position of the fracture liquid front as a function of time, under some simplifying assumptions, is shown to obey a nonlinear integrodifferential equation. Approximate analytic solutions are developed, showing that the movement of the liquid front exhibits three major flow periods: (1) at early time, the frontal position is determined by the fracture inlet boundary condition and the gravity-driven flow behavior of the fracture with negligible influence by the matrix; (2) at intermediate time, matrix imbibition retards the frontal advance against the pull of gravity; (3) at late time, the matrix approaches saturation and the frontal velocity approaches a limiting value. A two-dimensional numerical model is used to confirm the approximate solutions. Implications of model for nuclear waste storage are discussed. The analysis is applicable not only to fractured rock but also to lateral infiltration into coarse-grained sediments lying between layers of fine-grained soil.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6127060
• Journal Information: Water Resources Research; (United States), Journal Name: Water Resources Research; (United States) Vol. 27:8; ISSN 0043-1397; ISSN WRERA
• Country of Publication: United States
• Language: English

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Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
AQUIFERS
FLOW MODELS
FLUID FLOW
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GROUND WATER
HYDROGEN COMPOUNDS
HYDROLOGY
MANAGEMENT
MATERIALS
MATHEMATICAL MODELS
NUCLEAR FACILITIES
OXYGEN COMPOUNDS
POROUS MATERIALS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE FACILITIES
RADIOACTIVE WASTE MANAGEMENT
RADIOACTIVE WASTE STORAGE
RADIOACTIVE WASTES
RISK ASSESSMENT
SITE CHARACTERIZATION
SOILS
STORAGE
TWO-DIMENSIONAL CALCULATIONS
WASTE MANAGEMENT
WASTE STORAGE
WASTES
WATER