Study Of Top-coal Breaking Mechanism For Fully Mechanized Coal Caving Method

Improve the working surface recovery ratio has been the synthesis lets loose picks one of research core questions, therefore knew thoroughly goes against the coal failure mechanism, grasps goes against the basic rule which the coal destruction breaks down falls, to enhances the synthesis to put the working surface recovery ratio, realizes the security high production to have the important meaning highly effective.This paper uses laboratory MTS the coal sample mechanics characteristic experiment, the similar material modelling, the computer numerical calculus and the theoretical analysis method, north take constructs the coal mine 101 syntheses to put the working surface as the model object of study, let loose to the synthesis picks goes against the coal failure mechanism to conduct the quite thorough research.According to the laboratory MTS coal sample mechanics characteristic experiment, has analyzed the essential feature which the coal sample distortion destroys, fitted the experiment coal sample stress strain relationship, as well as failure criterion stress expression and strain expression; Has analyzed the coal in vivo jointing crevasse distributed characteristic, and the occurrence lets loose to the synthesis picks goes against the influence rule which the coal destroys; According to the similar material modelling, analyzed has gone against the coal breaking, to break down falls front the characteristic and the working surface the force of support distributed characteristic; The application numerical calculus analysis synthesis lets loose picks goes against the coal body stress field distribution characteristic, the displacement and the destruction differentiates Boott to draft; And controls through the analysis force of support distribution area goes against the area to go against the coal mechanics attribute, thought that the force of support distribution area went against the coal already to become the plastic medium, but controlled goes against the area to go against the coal to have the cutting slipping destruction; Using the fracture mechanics theory, established has gone against the overall mechanical model which the coal destroyed, and derived has gone against mechanics expression equation which the coal dilatancy destroyed.