Monitoring Rock Mass Deformation Using Time Domain Reflectometry.
O'Connor KM; Dowding CH; Su MB
Surface Crown Pillar Evalu for Active & Abandoned proceedings Ont Canada 11/89 Pp123-132 :10 pages
Time domain reflectometry (tdr) is an electrical pulse testing technique originally developed to locate breaks in power transmission cables. Recently, the U.S. Bureau of Mines has adapted this technique to monitor caving of rock induced by underground mining. Coaxial cables are grouted into a rock mass which is expected to cave, and the progressive rock movement deforms the cable. Consequently, there is a progressive change in cable deformation which produces changes in tdr pulse reflection signatures; these changes can be quantitatively related to the location and magnitude of rock mass movements.
Surface Crown Pillar Evalu. for Active & Abandoned...proceedings, Ont. Canada, 11/89, Pp123-132