Analysis of local fractures and crack growth in coal seams under compression

An analysis is performed for the effect that a growing rock pressure in stress concentration zones has on development of local fractures of coal due to stratal water, and on closing-up of bedding joints, which confines this process. It is shown that all of unstable cracks in a seam grow dynamically until the related bedding crack closing-up. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 3–9, March–April, 2006.