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Title: Mechanical properties of fractures from drillholes, UE25-NRG-4; USW-NRG-6; USW-NRG-7; USW-SD-9, at Yucca Mountain, Nevada

Technical Report ·
DOI:https://doi.org/10.2172/444078· OSTI ID:444078

Rock cores from drillholes UE25-NRG-4, USW-NRG-6, USW-NRG-7, and USW-SD-9 containing natural fractures were obtained from the Sample Management Facility at Yucca Mountain, Nevada. All recoverable fractures were sheared at constant normal stresses from 2.5 to 15 MPa, in the as-received condition (air-dry). Detailed profilometer data were collected from each fracture surface before testing. The tests yielded the normal closure as a function of normal stress, and the shear stress and dilation as functions of shear offset. The constitutive properties obtained from these stress-displacement relations were: normal stiffness, shear stiffness, shear strength, and dilation angle at peak shear stress. Shear strength plotted against normal stress for four thermomechanical units shows that friction angle varies from 370 to 460 and cohesion varies from 0.02 to 1.71 MPa.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE Office of Civilian Radioactive Waste Management, Washington, DC (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
444078
Report Number(s):
SAND-95-1736; ON: DE97004265; TRN: 97:006473
Resource Relation:
Other Information: PBD: Jan 1997
Country of Publication:
United States
Language:
English