Experimental studies of elastic-wave propagation in a columnar-jointed rock mass
Results are presented of a series of cross-hole acoustic measurements made between four horizontal boreholes drilled from a near-surface underground opening situated in a basaltic rock mass. The objectives of the programs were to assess the extent of blast damage around the opening, and to evaluate the rock mass characteristics and their spatial variation around the opening. The acoustic velocity and attenuation data are indicative of an anisotropic, jointed rock mass, with a greater intensity of jointing along travel paths in the horizontal than the vertical direction. Low acoustic P- and S-velocities are indicative of blast damage and of zones of intense jointing or fracturing. In this case blast damage extends to approximately 1.5 m from the face. Attenuation data appear to be less sensitive in distinguishing between the blast-damaged zone and intense vertical jointing and fracturing in the virgin rock mass. Taken together with field data, laboratory measurements of P- and S-wave velocities on intact core samples suggest that the rock mass is probably water saturated.
- Research Organization:
- Earth Science Div., Lawrence Berkeley Lab., Berkeley, CA
- OSTI ID:
- 7079522
- Journal Information:
- Geophys. Prospect.; (United States), Journal Name: Geophys. Prospect.; (United States) Vol. 34:8; ISSN GPPRA
- Country of Publication:
- United States
- Language:
- English
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Cross-hole acoustic measurements in basalt
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Related Subjects
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ACOUSTIC MEASUREMENTS
ANISOTROPY
ATTENUATION
BASALT
BENCH-SCALE EXPERIMENTS
BLAST EFFECTS
BOREHOLES
CAVITIES
DAMAGE
DATA ANALYSIS
DISTRIBUTION
DRILL CORES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
IGNEOUS ROCKS
MECHANICS
PHASE VELOCITY
RESEARCH PROGRAMS
ROCK MECHANICS
ROCKS
SATURATION
SEISMIC P WAVES
SEISMIC S WAVES
SEISMIC SURVEYS
SEISMIC WAVES
SPATIAL DISTRIBUTION
SURVEYS
VELOCITY
VOLCANIC ROCKS
WATER SATURATION
WAVE PROPAGATION