Analysis of roof fall hazards and risk assessment for Zonguldak coal basin underground mines

Abstract

The roof fall hazards are frequent problems of underground coal mines, which are generally unpredictable due to the associated uncertainties. These uncertainties, which arise from geological and stress conditions and mine environment, make the control of roof fall hazards difficult in underground coal mines. The most efficient method for coping with uncertainties in roof fall hazards is the use of risk assessment techniques. In this study, a risk assessment and management methodology is proposed for roof fall hazards in underground mines of the Zonguldak coal basin. The annual rates of roof falls obtained from the five mines in the basin are statistically analyzed. The components of risk, which are the probability of roof fall and consequences of roof fall hazard are identified and quantified. The probability of roof fall is computed by fitting a distribution function to the annual roof fall, while the consequences of roof falls are quantified based on a cost model. Then a decision analysis methodology for evaluating the performance of possible alternative action to be taken in order to decrease the risk, is developed. The results show that the underground coal mines in the Zonguldak coal basin have considerably high risk levels and hence require comprehensive risk management schemes.