Analysis of gas-dynamic phenomenon in underground coal mines in the central basin of Asturias (Spain)

• Gas-dynamic phenomena in underground coal mining.
• Influence of soil stresses on gas-dynamic phenomena.
• Influence of the concentration of methane gas and its rate of desorption on gas-dynamic phenomena.
• Influence of unmined massifs and changes in the thickness of the seam on gas-dynamic phenomena.

This paper aims to analyse and understand the origin and development of gas-dynamic phenomenon (GDP) that take place with certain regularity in underground coal mining. It provides a detailed analysis of how they are influenced by changes and increases in ground stresses (vertical and horizontal stresses) and variations in the pressure of methane gas contained in underground coal seams used for mining operations.Phenomenon of this nature have occurred in recent years in certain seams at the Sotón, Montsacro and San Nicolás pits in the central coal basin of Asturias (Spain). Describing and analysing them reveals the influence of the proximity of other operations at different levels of the same seam or located in different seams. Similarly, it indicates the influence of unmined zones and brusque changes in the thickness of the seam. The values of the concentration of gas at the coal face of the mined seam and its rate of desorption complement and justify all the previous explanations. The measurements taken were periodically obtained by means of boreholes in coal faces for coal seams mined using the sub-level method.