Instrumentation for Monitoring Load on Supports in Underground Coal Mines – Case Studies

Abstract

This paper presents an overview of various types of instrumentation including load cells, and techniques of evaluation of load on supports in underground coal mine emphasizing the importance of Vibrating Wire type of load cells for monitoring load on supports in underground mines. Support systems used in typical blasting gallery panels in three typical underground coal mines are critically reviewed. In general, the capacity of the hydraulic supports used in underground coal mines for the development and depillaring workings is about 40 to 50 tons. Vibrating wire type sensors have been predominantly used for the measurement of load on these supports. Maximum load observed on the supports is about 50% of the capacity of the maximum support indicating adequacy of the support system in the respective underground mines with adequate safety factor. Recent innovations and the need of wireless sensor networks for continuous online monitoring for load cells is also emphasized for better understanding of behavior of supports.