Flow focusing in unsaturated fracture networks: A numerical investigation

Journal Article · Thu Apr 17 04:00:00 EDT 2003 · Vadose Zone Journal

OSTI ID:837731

Zhang, Keni ^[1]; Wu, Yu-Shu; Bodvarsson, G S; Liu, Hui-Hai

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1. LBNL Library

A numerical modeling study is presented to investigate flow-focusing phenomena in a large-scale fracture network, constructed using field data collected from the unsaturated zone of Yucca Mountain, Nevada, the proposed repository site for high-level nuclear waste. The two-dimensional fracture network for an area of 100 m x 150 m contains more than 20,000 fractures. Steady-state unsaturated flow in the fracture network is investigated for different boundary conditions and rock properties. Simulation results indicate that flow paths are generally vertical, and that horizontal fractures mainly provide pathways between neighboring vertical paths. In addition to fracture properties, flow-focusing phenomena are also affected by rock-matrix permeability, with lower matrix permeability leading to a high degree of flow focusing. The simulation results further indicate that the average spacing between flow paths in a layered system tends to increase and flow tends to becomes more focused, with depth.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Office of Civilian Radioactive Waste Management. Yucca Mountain Site Characterization Office (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 837731
• Report Number(s): LBNL--52819
• Journal Information: Vadose Zone Journal, Journal Name: Vadose Zone Journal Vol. 3
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
BOUNDARY CONDITIONS
FOCUSING
FRACTURE PROPERTIES
FRACTURES
PERMEABILITY
RADIOACTIVE WASTES
SIMULATION
YUCCA MOUNTAIN