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Controlled sources for shear‐wave surveys in mines [Link]
- Source: Geophysical Prospecting, Volume 48, Issue 3, Dec 2000, p. 399 - 414
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- 24 Dec 2001
Abstract
The ability to analyse shear‐wave anisotropy in a mine environment is greatly aided by using multiple source orientations of a reproducible, impulsive shear‐wave source. The analysis of what is probably the first controlled source shear‐wave experiment in a mine environment demonstrates clearly that shear‐wave polarizations and time delays between split shear‐wave arrivals are reliably measured because of the use of multiple source orientations rather than a single shear‐wave source. Reliability is further aided by modelling the shear‐wave source radiation pattern, which allows for the unequivocal discrimination between seismic raypaths where shear‐wave splitting did and did not occur. The analysis also demonstrates the great importance of high reproducibility of the seismic source for the use of shear waves in time‐lapse surveys to monitor changes in a rockmass.