Rock Fracture Measurements: A New Use for Time‐Domain Reflectometry

摘要

The cliper system is a real‐time instrument for locating fractures in the rock surrounding a nuclear explosion. An array of transducer cables is emplaced in the region surrounding the nuclear explosive, and their lengths are continuously monitored for a period of time after the nuclear detonation. After detonation, the cables are shortened by the action of the explosive phenomenology of vaporization, plastic deformation, rock fracture, and finally chimney formation. Time‐domain reflectometry is used to measure the changes in cable length. A record of these changes in length is used to correlate the explosive phenomenology with time, and thus generate an on‐line picture, above ground, of the underground activity as it develops. Typical applications of the cliper system are demonstrated with rock‐fracture data and chimney formation data.