Effects of heterogeneity and friction on the deformation and strength of rock
- Lawrence Berkeley Lab., CA (United States)
- Univ., of Arizona, Tucson, AZ (United States). Dept. of Mineralogy and Geological Engineering
Experimental observations of the evolution of damage in rocks during compressive loading indicate that macroscopic failure occurs predominantly by extensile crack growth parallel or subparallel to the maximum principal stress. Extensile microcracks initiate at grain boundaries and open pores by a variety of micromechanical processes which may include grain bending, Brazilian type fracture and grain boundary sliding. Microstructural heterogeneity in grain size, strength and shape determines the magnitude of the local tensile stresses which produce extensile microcracking and the stability with which these microcracks coalesce to form macrocracks. Friction at grain boundaries and between the surfaces of microcracks reduces the strain energy available for extensile crack growth and increases the stability of microcrack growth. In clastic rocks, frictional forces may improve the conditions for extensile microcrack growth by constraining the amount of sliding and rotation of individual grains. Micromechanical models are used to investigate the effects of heterogeneity and friction on the deformation and strength of crystalline and clastic rocks.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 10158060
- Report Number(s):
- LBL-35457; CONF-940984-3; ON: DE94013099; CNN: Grant MSS9022381
- Resource Relation:
- Conference: Europe-U.S. workshop on fracture and damage in quasibrittle structures: experiment, modeling and computer analysis,Prague (Czech Republic),21-23 Sep 1994; Other Information: PBD: Mar 1994
- Country of Publication:
- United States
- Language:
- English
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