This project is intended to upgrade the ultrasonic measurement system in the Rock Mechanics Laboratory at The Pennsylvania State University. A new pulse generator, and a new digital oscilloscope will be the main components of the upgraded system. The strain relaxation of rocks that have been subjected to stress has two major components; one is instantaneous and the other is time-dependent. In large part the time-dependent strain relaxation of a rock involves the formation and opening of microcracks, and this relaxation can be monitored by measuring the changes in the ultrasonic properties of the rock. The upgraded ultrasonic measuring system will allow the Rock Mechanics Laboratory to fully exploit the potential of the time-dependent strain relaxation technique for interpreting the stress history of rocks under deep earth conditions.
