Constitutive model for ubiquitously jointed rock masses

Conference · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6940321

Johnson, R L; Thomas, R K

A material constitutive model is presented for jointed rock masses which exhibit preferred planes of weakness. This model is intended for use in finite element computations. The present applications are computations involving stability of underground openings in hard rock, but the model seems appropriate for a variety of other static and dynamic geotechnical problems as well. Starting with the small strain finite element representations of a two-dimensional elastic body, joint planes are modeled in an explicit manner by direct modifications of the material stiffness matrix. A novel feature of the model presented is that joint set orientations, lengths and spacings are readily assigned through the sampling of a population distribution statistically determined from field measurement data. The result is that the fracture characteristics of the formations have the same statistical distribution in the model as is observed in the field. Two mechanisms of failure are modeled, including slip along existing joint planes and failure of the rock matrix by splitting or shearing, each resulting in redistribution of stress due to modification of the material stiffness.

• Research Organization: New Mexico Univ., Albuquerque (USA). Dept. of Civil Engineering; Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6940321
• Report Number(s): SAND-81-2443C; CONF-830104-5; ON: DE82020182
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
FAILURES
FINITE ELEMENT METHOD
FRACTURE MECHANICS
FRACTURES
MATHEMATICAL MODELS
MECHANICS
NUMERICAL SOLUTION
ROCKS