Experimental study of opening-mode crack growth in rock. Progress report

Technical Report · Mon Feb 01 04:00:00 EST 1982

OSTI ID:5498092

Gordon, R B

The first objective of the research reported here is to find test conditions that will permit reliable and reproducible measurement of the fracture energy of rock. The second objective is to use such measurements to investigate the relation between fracture toughness and the rock microstructure and mineral content of rock. A survey of all available published data on the fracture energy of rock has been made to see the extent to which consistent values have been obtained in the past laboratory studies. The results show that there is an enormous variation in published values for a given type of rock and that this variation obscures the physical processes that control the toughness of rock. Hence a series of measurements on different types of rock with a standardized test procedure has been used to find differences in fracture energy that are due to the structure and composition of different types of rock. It is found that the variations in fracture energy between different types of rock are large compared to the errors of measurement and it can be understood, at least in part, in terms of the microstructural processes by which fracture takes place. Additional experiments have been done to explore the effects of water on the fracture energy and the effects of texture in the microstructure of the rock. Finally, a new technique, the measurement of the internal friction of the rock while the crack is being propagated through the test specimen, is used to help reveal the development of the process zone of microcracks that precedes the development of the open crack during the fracture test.

• Research Organization: Yale Univ., New Haven, CT (USA). Dept. of Geology and Geophysics
• DOE Contract Number: AC02-79ER10445
• OSTI ID: 5498092
• Report Number(s): DOE/ER/10445-2; ON: DE82008784
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
FRACTURE PROPERTIES
FRICTION
HYDROGEN COMPOUNDS
INFORMATION
INTERNAL FRICTION
MECHANICAL PROPERTIES
MICROSTRUCTURE
MINERALOGY
NUMERICAL DATA
OXYGEN COMPOUNDS
ROCKS
TESTING
VARIATIONS
WATER