The Development of Rock Failure Electromagnetic Emission Monitoring System

Abstract

The research about electromagnetic emission (EME) during rock failure is very important to earthquake prediction and mine safety. A corresponding monitoring system has been developed according to the characteristics of EME signals during rock fracture, which include a wide frequency band and small amplitude of the inductive signals. The system is constituted by electromagnetic induction probe, signal-conditioning circuit and a computer for data acquisition. Among them, the electromagnetic induction probe can detect spatial magnetic field changes in a certain direction and convert it into electrical signals, the signal-conditioning circuit can magnify, filter and isolate signals acquired by the probe, and the computer for data acquisition is used for recording and displaying the detected signals. Several testing results have been achieved in rock failure experiments on marble that are carried out both by mechanical loading and expansion caused by chemical agents.