Seismic Pulse Broadening Associated with Fracture Damage Caused by Explosions in Crystalline Rock.

摘要

Recent analyses of the initiation, propagation, and linkage of fractures from pre-existing cracks have been used to formulate a damage mechanics for brittle solids loaded in compression. The model describes the accumulation of damage with strain. It has been used to construct damage initiation surfaces and failure surfaces which have been tested using previously published experimental data. It is shown that a damage mechanics rheology can produce seismic pulse-broadening observed in underground tests in granitic rock. It is proposed that the basic scaling relation between the size of the pre-existing cracks and the stress required to initiate damage may explain why models based on laboratory data and large scale laboratory simulations have failed to reproduce the pulse-broadening observed in the field. (rrh)