STRENGTH AND DEFORMATION PROPERTIES OF ROCK-LIKE MATERIALS TESTED IN TRIAXIAL COMPRESSION.

A study of the influence of strain rate on strength using different confining pressures shows that with the exception of the unconfined state this dependence remains unaffected. In the absence of satisfactory criteria for predicting the strength of rock-like materials under multiaxial states of stress a simple construction, using triaxial results, is suggested. Results available in literature are examined in order to isolate parameters having an effect on the strength-confining pressure relationship. The rate of change of both strength and deformation properties was found to decrease with increasing confinement. Transition of failures from brittle to ductile took place at confining pressures approximately equal to the unconfined strength values.