Example of fracture characterization in granitic rock

The Stripa mine, located in southcentral Sweden, is an inactive iron mine which incorporates a massive, medium-grained quartz monzonite pluton within its workings. The experimental site is at a depth of 338 m in the pluton and approximately 150 m from the contract with the synclinal ore body. As part of an integrated program of rock mass characterization, the work described here pertains to a specific heater test, termed the ''time-scaled'' experiment, designed to investigate long-term thermal effects. A rock volume of roughly 6 x 30 x 15 m3 is involved, containing an array of eight 1-kw electrical heaters. The heaters simulate radioactive waste canisters scaled by a factor of 0.32, which according to laws of similitude and heat conduction allows a ten-fold compression of the time scale. The heater test was concluded in late 1979, and the data reported here are being incorporated into analyses and models of the experiment