THE CHANGE IN ULTRASONIC WAVE VELOCITIES IN TRIAXIALLY STRESSED BRITTLE ROCK

摘要: The changes in the ultrasonic wave velocities were measured for granodiorite under axial stress up to failure, and confining pressure 1kbar. begin decrease at differential of 1-2kbar show a marked higher than 70% failure strength. observed P velocity minimum direction is remarkable (25% maximum) that S somewhat smaller (15% maximum). decrement maximum very small compared with direction.The normalized Y(≡υ/υmax, ratio one each run) empirically represented by function X(=Δσ/σSM, stressΔσ strength σSM same pressure), as follows, Y=√1-a-Xbwhere b are constants. An elasticity theory composite materials was used interpret this relation.