Monitoring the spontaneous combustion zone of a rock-coal massif using the ground-penetrating radar method

Abstract

Introduction. Endogenous fires are common and one of the most complex types of accidents in the mining industry. The main cause of endogenous fires is oxidation of combustible rock by oxygen. Existing fires significantly complicate mining operations, lead to the loss of coal reserves prepared for excavation, expensive coal-mining equipment, and cause huge economic losses associated with firefighting operations. Fired areas are sources of emissions of gases harmful for breathing into the atmosphere, so the environmental damage is also very significant. Due to the fact that endogenous fires are difficult to predict and forecast, especially in their initial stages, their study is relevant to scientists of the leading research institutes of the mining industry. Research objective is to investigate and analyze the effectiveness of the ground-penetrating radar (GPR) method for diagnosing the spontaneous-combustion zones of the rock-coal massif. Methods of research. In order to assess the effectiveness of the GPR method, field experimental studies on the recognition and localization of underground fires were carried out. In order to determine the informative value of this method, wells were drilled and geological data was compared with the GPR survey results. Results. The site of an active underground fire was visually inspected to predefine the combustion areas; inspection results were presented in the paper. Using the method of GPR sounding and based on the typical anomalous zones location on fire radiograms, the fire sources were diagnosed by depth and on the plan. Boreholes were drilled to study the lithological structure of the rock mass. Additional GPR sounding was aimed at defining the width of the fire in plan more precisely. Conclusions. The GPR method makes it possible to obtain on-line data on the location of coal massif spontaneous-combustion zones and their sizes. This technology contributes to timely measures for preventing the development of underground fires in the territories of mines and open pits surface plants.