Early Detection of Rock Movement with Time Domain Reflectometry
Publication: Journal of Geotechnical Engineering
Volume 120, Issue 8
Abstract
Remote operation of a time domain reflectometry (TDR) system demonstrates the effectiveness of telemetric monitoring for early detection of rock movement. During field testing reported here, TDR data were related to shear deformation above a longwall caving operation using a correlation between the signature reflection coefficient and shear deformation established through laboratory measurements. A 175‐m (575 ft) long vertical coaxial TDR cable was grouted into the rock mass above the longwall coal‐mining operation and attached to the aboveground‐pulsing instrument. TDR data were then remotely acquired twice daily by an operator some 500 km away. Comparison of TDR signature changes with longwall‐face location showed that localized changes were detected four days before surface subsidence occurred when mining was still 64 m (210 ft) away. Since the mining was moving toward the cable at a rate of 10 m/day, a warning interval is expected to be larger for premined sites with lower deformation rates.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Bauer, R. A., Dowding, C. H., Van Roosendaal, D. J., Mehnert, B. B., Su, M. B., O'Connor, K. M. (1991). “Application of time domain reflectometry to subsidence monitoring.” Final Rep., Assistance Agreement No. HQ51‐CT6‐01537, U.S. Dept. of the Interior, Washington, D.C.
2.
Bennett, R. M., Drumm, E. C., and Lin G. (1992). “Evaluation and analysis of remedial measures for earth‐structure damage mitigation.” Final Rep., U. S. Bureau of Mines Contract No. SO278058, University of Tennessee, Knoxville, Tenn.
3.
Dowding, C. H., Su, M. B., and O'Connor, K. M. (1988). “Principles of time domain reflectometry applied to measurement of rock mass deformation.” Int. J. Rock Mech. Min. Sci. Geomech. Abstract, 25(5), 287–297.
4.
Dowding, C. H., Su, M. B., and O'Connor, K. M. (1989). “Measurement of rock mass deformation with grouted coaxial antenna cables.” Rock Mech. and Rock Engrg., 22, 1–23.
5.
“Geophysical logging of wireline drill hole at heron rd. subsidence research site.” (1991). Service Contract No. PO213265, U.S. Bureau of Mines, Minneapolis, Minn.
6.
Goodman, R. E. (1989). Introduction to rock mechanics, 2nd Ed., John Wiley & Sons, New York, N.Y.
7.
Huang, F. C., O'Connor, K. M., Yurchak, D. M., and Dowding, C. H. (1993). “NUMOD and NUTSA: software for interactive acquisition and analysis of time domain reflectometry measurements.” Information Circular 9346, U.S. Department of the Interior, Washington, D.C.
8.
Huang, F. C. (1993). “Telecommunication enhancement of time domain reflectometry measurements.” PhD dissertation, Northwestern University, Evanston, Ill.
9.
Kim, M. H. (1989). “Quantification of rock mass movement with grouted coaxial cable,” MS thesis, Northwestern University, Evanston, Ill.
10.
Mehnert, B. B., Van Roosendaal, D. J., and Kawamura, N. (1992). “Overburden characterization for heron road subsidence site.” Final Rep. to U.S. Bureau of Mines, PO213293, Illinois State Geological Survey, Champaign, Ill.
11.
Peterson, D. (1991). Internal Rep. Syncrude Canada, Ltd., Edmonton, Alberta, Canada.
12.
PROCOMM version 2.4 reference manual. (1986). DataStorm Technologies, Columbia, Mo.
13.
SP232 host application program user guide. (1990). Tektronix, Inc., Redmond, Oreg.
14.
Su, M. B. (1987). “Quantification of cable deformation with time domain reflectometry techniques,” PhD Dissertation, Northwestern University, Evanston, Ill.
15.
Wiring systems product catalog. (1991). Anixter Bros., Inc., Skokie, Ill.
Information & Authors
Information
Published In
Copyright
Copyright © 1994 American Society of Civil Engineers.
History
Received: Feb 23, 1993
Published online: Aug 1, 1994
Published in print: Aug 1994
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.