Details:

Personal Author:
Westman, E. C. ; Luxbacher, K. D. ; Swanson, P.L. ;
Westman, E. C. ; Luxbacher, K. D. ; Swanson, P.L. ; Less -
Corporate Authors:
Spolane Research Laboratory (National Institute for Occupational Safety and Health) ;
Description:
Three-dimensional velocity tomograms were generated on a daily basis to image mining-induced changes to the overburden above a longwall mine. The hypothesis was that a coherent redistribution of seismic velocity, due to the development of high-stress zones, could be imaged at the mine scale. Seam depth was 360 m and source location depth varied from 100 to 1000 m. Sixteen geophones were distributed over a 600 by 600 m square area on the surface above the mine. More than 12,500 events were recorded over an 18 day period. The recorded seismicity provided input for the local-earthquake tomography code, SIMULPS. Eighteen tomograms were generated and high-velocity regions correlated well with high abutment stresses. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated. These results indicate that velocity tomography can be used to provide a better understanding of temporal changes within a rock mass, and can potentially be used to produce a better understanding of the mechanisms that lead to unanticipated ground failures.
Subject:
[+]
Mining

Source:
42nd U.S. Rock Mechanics Symposium/2nd U.S.-Canada Rock Mechanics Symposium, June 29 - July 2, 2008, San Francisco, California Alexandria, VA: American Rock Mechanics Association, Paper No. 08-299, 2008 Jun; :1-7
Document Type:
Book Chapter ;
Genre:
Conference Publications ;
Collection(s):
National Institute for Occupational Safety and Health
Main Document Checksum:
[+]
urn:sha256:df510d0ea1abe43f5efadb39d91ebf3f70d854aac536a1f8019ba93214c27919
File Type:

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