Development of a low frequency strata movement warning system and its application in mining

摘要

Analysis of the causes of accidents in mines and tunnels indicate that the maximum number of fatalities and injuries are due to fall of roof or fall of side. An early warning system for roof fall can save valuable human lives as well as machines. Central Mining Research Station, Dhanbad has developed a simple Strata Movement Warning System (SMWS) based on low frequency acoustic technique for prediction of roof fall in underground mines. The nature of the microseismic waves emitted through strata and their propagation characteristics have been briefly described in the paper. This knowledge has been utilised for the designing of the strata movement warning system. The essential components of the system are: the acoustic sensor, passive low frequency filter, pre-amplifier, band pass filter, line isolator, control and audio-visual alarm unit. The paper describes briefly each of these units. The paper also describes the field installation of such a system in an underground mine.