Discrete Element Analysis On The Waterproof Pillar To Coal Seam Mining Goaf Beside Large Fault

Not only the theoretical basis of Discrete Element Method (DEM) but also the classification and characteristics of DEM were discussed. For coal mining in the mined-out area surrounding rock caving, cracking, deformation phenomena, UDEC4.0 software was used in the numerical calculation to the distribution of displacements and stresses surrouding mining goaves of seam 10# and seam 81 about fault F2 in Taoyuan Coal Mine, and proper width of waterproof pillar to the fault. Main contents are:â‘ Water-bearing and water-resisting features of Coal-bearing beds and related strata were analyzed. Evaluation and analysis about the material composition and physics mechanics of the fault F2 were analyzed.â‘¡Order formula was used to calculate the width of waterproof pillar of seams 10# coal and 81# corresponding to different safety factor. Based on Tectonic model of DEM about Mohr-Coulumb Constitutive continuous medium and Joint area contact-coulomb slip with residual strength joints media, referring to Taoyuan Coal Mine Stratigraphy and fault F2, a variety of coal pillars of seam 10# and seam 81# under the conditions of deformation and failure characteristics of rocks were simulated, and non-linear relationship between the fault waterproof pillar width and thickness of the seams was researched, and the reasonable value of coal pillar width about seam 10# and seam 81# is also tried.â‘¢By a in-depth analysis to practical deficiencies of fault waterproof pillar formula in the professional regulation, the mechanics meaning and application characteristics of the formula, the irrationality of a linear relationship between seam thickness and pillar width, as well as the contradiction between that and the actual laws of fractured, were pointed out lacement angle theory was led to analyze the applicable conditions and defects of the design calculation on water-proof pillar to faults.