Permeability of Apache Leap Tuff: Borehole and core measurements using water and air
- Univ. of Arizona, Tucson, AZ (United States)
Characterization data for water and air properties of variably saturated rocks are required for evaluation of the candidate high-level nuclear waste disposal site at Yucca Mountain, Nevada, as well as for municipal, toxic, and hazardous waste sites situated in variably saturated fractured rock elsewhere. Field and laboratory methods for estimating and interpreting parameters obtained from field borehole and laboratory core experiments are examined using permeability data interpreted from air and water injection tests in variably saturated fractured tuff at the Apache Leap Tuff Site in central Arizona. The tuff at the field site has a matrix porosity of approximately 17.5% and contains numerous near-vertical fractures at an average spacing of 1.3 m. More than 270 m of 6.4-cm-diameter oriented core were collected from boreholes. Laboratory estimates of absolute permeabilities using air and water as the test fluids were acquired at a range of matric potentials for 105, 5-cm-long core segments extracted at approximately 3-m intervals containing no obvious fractures. Field scale estimates of fractured rock permeabilities using air and water as test fluids were obtained at ambient matric suctions and water saturated conditions, respectively. The field tests were conducted along 3-m intervals within boreholes with the intervals centered on core sampling positions. Permeabilities measured in boreholes using air are shown to provide good estimates of permeabilities measured using water into initially unsaturated, fractured rock at the Apache Leap Tuff Site.
- OSTI ID:
- 140528
- Journal Information:
- Water Resources Research, Vol. 29, Issue 7; Other Information: PBD: Jul 1993
- Country of Publication:
- United States
- Language:
- English
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