MEASURING METHOD OF MECHANICAL CHARACTERISTICS AND INITIAL STRESS OF ROCK-BED

摘要

PURPOSE: To enable simultaneous measurement of the mechanical characteristics and the initial stress of a discontinuous rock-bed by emitting an elastic wave at different depths in a bored hole and by detecting the elastic wave in the other bored hole. CONSTITUTION: Elastic wave generating-seizing devices are set at three points in the depth direction respectively in two holes (a) and (b) made by boring or the like. Then, elastic waves are emitted sequentially from arbitrary elastic wave generating devices 1, 2 and 3 in one of the holes (a) and (b) and seized by seismometers 1, 2 and 3 in the other of the holes (b) and (a). The results of the seized elastic waves are put in an equation Vij=f (d, ds, θ) in which V denotes the velocity of the elastic wave, (d) an initial stress, (ds) an interval of discontinuous planes, θ a tilt angle of the discontinuous plane and (i) and (j) numbers of measuring places in the holes (a) and (b), and by establishing simultaneous equations thereof, the initial stress, the interval of the discontinuous plane and the tilt angle of the discontinuous plane can be obtained.