Study On "S-L-G" Coupling Effect Of Steep Coal Seam In Fully-mechanized Caving Mining

Steep coal seams refer to the occurrence of 45-90°angle of the seam. Since the formation of steep coal seam is due to the late geological formation motion, so its occurrence conditions,coal seam structure,mining stress environment,geomechanics conditions are more special than other kinds of coal seams'occurrence environment. During its exploration, the rules of rock movement, mine water movement and gas migration are more complex than other conditions coal seam's rules. Therefore, the study of "solid-liquid-gas" (S-L-G) coupling effect process during mining the steep coal seam is great significance for improving production technology on site, or the development of mining theory in steep seam.Papers mainly research on the fully-mechanized caving of the steep coal seam, using the technical means of "solid-liquid-gas" three-phase mediator physical simulation experiments, numerical calculation,and combination of on site production practice,we analysis the features of coupling effect process of "solid-liquid-gas" three-phase mediator during mining in steep coal seam.Research shows that, coal seam belongs to medium-hard seam,it contains lots of cleavages and fissures;the capicity of absorbing methane is poor, and methane.is easy to release. And pore connectivity in coal seam is poor,while the capacity of water-holding is extremely strong,face and roadway can easily generate plastic deformation,inclined to occur overall collapse or shear slip,easily formating the potential risks of mine water or gas disaster influxing into face.In the region of mining disturbances, damage degree of surrounding rock,the strength and amplitude of destruction have significantly difference,surrounding rock deformation and collapse has obvious non-symmetry,periodic pressure behavior shows strong,displacements,acoustic emission target and related characteristics parameters,the three identification modes of coal and rock,damage,accelerated destruction and transient failure are obtained under coupling effect of three-phase mediator,which provides quantitative parameters for predict dynamic buckling on-site, and has some reference for safety mining on-site.