关键词: 煤柱, 破坏倾向性, 危险指数, 数值计算

Abstract: Depending on actual compression conditions of on-site coal pillars, based on the characteristics of compression shear and tensility of rock mass damages, risk indexes of compression shear failures and tensile failures of coal pillars have been established through theoretical analysis, and the study has also analyzed the distribution laws of risk indexes of complicated compressed coal pillars and damage proneness characteristics of coal pillars, by adopting the method of numerical simulation, under conditions of different width-height ratios. The study has found that with the increase of coal pillar width, the compression-shear damage proneness, in turn, presents the characteristics of an elliptic structured type, an “X” + half elliptical, a half elliptical + double funnel type, and a half elliptical + double trapezoid structured type; tensile fracture proneness presents the characteristics of a rectangle hyperbola structure, an “X” + half elliptical, a double funnel type, and a double trapezoidal like structure. The ratio of height and width of coal pillars on risk indexes is of the periodic feature, showing itself as three stages of dramatic, gentle and zero impacts. The distribution of maximum principal stress represents an obvious end impact, when coal pillars compressed, complying with the Saint-Venant’s Principle.

Key words: coal pillar, damage proneness, risk indexes, numerical simulation