The Influence of Fracture Strain Energy on the Burst Tendency of Coal Seams and Field Application

Abstract

Coal is typically considered a special engineering rock mass because of its low strength, high internal fracture development, good permeability, and random distribution of microparticles and fractures. The results of cyclic loading and unloading tests indicate that the strain energy during the coal deformation process can be divided into three parts: plastic strain energy; fracture strain energy; and base-material strain energy. The energy composition ratio differs depending on coal strength. Lower proportions of fracture strain energy are associated with higher elastic energy indexes, and there is a negative correlation between fracture strain energy and other coal burst tendency indexes. The results were applied on the 4206 isolated island working face of coal mine A in Yan’an, Shanxi, China, yielding good benefits. The findings presented here provide a theoretical basis for understanding the principle of coal seam bursting and guidance for reducing burst risks.