Early Warning System of Impending Rock Failure for Safety in Mines and Excavations.

摘要

This research was undertaken to develop a system capable of detecting changes in the structure of rocks,leading to failure of mine roofs,and/or excavations. A prototype system was developed,field tested,and delivered to the Bureau of Mines for further evaluation and research. This system is based on the analysis of acoustic signals generated on the surface of the roof by an impact device and which are reflected or backscattered by flaws and discontinuities in the rock. The specially designed impact source is capable of generating high frequency acoustic signals with excellent repeatability. The system can also be used in conjunction with conventional acoustic pulse transducers. The received signal is digitized and the data transferred to a minicomputer for processing and display. This capability allows the immediate determination of wave velocity and/or distance to a reflecting interface.