Instrumentation and Computer Based Data Acquisition for in-Situ Rock Property Measurements

This paper discusses instrumentation and computer based data acquisition for in-situ rock property measurements as applied to an experiment conducted at Stripa, Sweden in cooperation with the U. S. Department of Energy and the Swedish government. Electrical heaters were installed in an underground granite mass to simulate thermal loading by canisters of high-level nuclear waste. Extensometers, borehole deformation gages, vibrating wire stress meters, and thermocouples were used to monitor the thermomechanical response of the granite. A computer based data acquisition system recorded data, performed on-line computations and provided graphic output. A summary description is given of the experiment areas, heater systems, data acquisition hardware, and four types of instruments used for the in-situ rock property measurements.