HR: 1330h
AN: H42F-1143    [PDF]
TI: The role of fracture intersections in DNAPL migration below the water table
AU: * Ji, S
EM: ji0511@snu.ac.kr
AF: Seoul National University, School of Earth & Environmental Sciences, NS80 Seoul Natl Univ, Seoul, 151-747 Korea, Republic of
AU: Nicholl, M J
EM: nicholl.geo@yahoo.com
AF: University of Idaho, Mining and Geological Engineering University of Idaho, Moscow, ID 83844-1011 United States
AU: Glass, R J
EM: rjglass@sandia.gov
AF: Sandia National Laboratories, Flow Visualization and Processes Laboratory Sandia National Laboratories, Albuquerque, NM 87185 United States
AU: Lee, K
EM: kklee@snu.ac.kr
AF: Seoul National University, School of Earth & Environmental Sciences, NS80 Seoul Natl Univ, Seoul, 151-747 Korea, Republic of
AB: Dense non-aqueous phase liquids (DNAPL­_s) are a common source of groundwater contamination. Because DNAPL­_s are denser than water, they may rapidly migrate through surficial sediments and enter fractures within the underlying bedrock. In order to locate, assess, and remediate DNAPL­_s within fractured bedrock, we must first understand the distribution, or structure, of the fluid phases (water and DNAPL) within the fracture network. Phase structure will be ultimately dependent on the mechanisms through which a DNAPL invades the water-saturated fracture network. Previous numerical simulations and experimental observations in two-dimensional fracture networks have shown that aperture variability, network geometry, and horizontal groundwater flow all affect the balance between capillary, viscous, and gravitational forces that controls DNAPL invasion. However, two-dimensional fracture networks restrict the influence of intersections between fractures, which may form their own network of barriers or conduits. Here, we conduct simple experiments to consider the influence of a single three-dimensional fracture intersection on DNAPL invasion. Artificial intersections are fabricated from glass plate to allow visualization of the invasion process. We then conducted experiments over a range of intersection geometries and boundary conditions. Observations are compared to simulations based on a Modified Invasion Percolation (MIP) model. Results show that intersection geometry influences DNAPL migration, and thus the three-dimensional phase structure of DNAPL in fractured rocks.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 5104 Fracture and flow
DE: 5139 Transport properties
SC: Hydrology [H]
MN: 2003 Fall Meeting