The Study On Damage Law Of Mechanicsand Seepage Of Coaland Rock Based On Miniature Specimen

With China’s economic rise, the major project of the construction of theprograms are in place, a lot of big projects are involved in rock mechanics and rockseepage learn knowledge.In these areas of some professional research is not enoughto solve practical engineering problems, especially in some miningengineering.Therefore, the research of coal and rock material mechanics andseepage damage law, has very important engineering significance。For decades, themechanics of coal and rock materials and the seepage study, focused on research ofsome large and medium-sized specimen deformation damage law.In a small, evenin the research field of miniature specimen, the results were rare.Therefore, thisarticle, focusing on the experimental study of miniature coal and rock specimens,can make up this gap. Through the analysis of material properties, select the yellow powdersandstone and jincheng anthracite as main test in this paper,15specimens materials,and selected the6mm diameter, length of12mm specimen.Miniature tester tominiature specimen for coal and rock under uniaxial compression, triaxialcompression, cooperate with in this paper, design of experiment system, the coaland rock seepage in the coal and rock series of studies.Tester and computedtomography (CT) system, coal and rock will be completed on coal and rockmechanics of materials and fracture seepage research, obtained a large amount ofdata.This article mainly USES the experimental study and theoretical analysis toanalyze the micro specimen of the coal rock mechanics and seepage damage law.Interms of theoretical analysis, respectively from the coal and rock mechanicsresearch and study of coal and rock seepage two aspects.Coal and rock damagemechanics is mainly analyzes the coal and rock deformation theory, thedevelopment of the coal and rock mechanics experiments and the characteristics ofcoal and rock the whole stress-strain curve.Coal rock seepage study mainlyanalyzes the water-coal and rock interaction theory, seepage theory and coal rockunder the action of stress and seepage coupling seepage theory.Uniaxial compression experiments proved that the strength and deformation ofthe coal and rock material is not only related to material contains mineral grains,also affected by the internal fracture pore structure form, size.Sandstone strength and deformation of the specimens is related to diameter ratio and size of thespecimens, and the intensity of anthracite coal specimen has obvious anisotropyand deformation.Triaxial compression experiments show that with the increase ofconfining pressure, all kinds of strength and deformation of the specimens arecorresponding.Through the analysis of residual strength, and points out that theyellow sandstone belong to the brittleness of rock material, the anthracite are partialplastic.Softening of uniaxial compression experiments show that with the increaseof immersion time (moisture content), coal and rock material in water softening,strength and deformation of large changes have taken place, showed flooding tosoften the anisotropy of anthracite coal.Seepage experiment of coal material, pointsout that the coal rock seepage is closely related to internal fracture structure,confining pressure, must be with the increase of osmotic pressure, the strength anddeformation decrease gradually.Burst of coal and rock seepage law study found,confining pressure and osmotic pressure on the seepage properties of coal and rockmaterial plays a decisive role.Osmotic pressure, must be confining pressureincrease, the flow per unit time into negative exponential decline, coefficient ofpermeability and permeability decrease.Confining pressure, certain osmoticpressure increase, the situation is the opposite,due to the adsorption of water,permeability coefficient and a decrease in permeability first, after rising.ThroughCT, the influence factor of the failure deformation and seepage of coal rock specimen is analyzed, and the percolation probability of the cracked coal rock isrelated to the confining pressure and the osmotic pressure..Although there are still many experimental design and operation of theshortcomings, but through the experimental study and theoretical analysis of thisarticle, from a certain extent, reveals the for miniature specimen of the coal rockmechanics and seepage damage law, has the vital significance.The paper issupported by the National Natural Science Foundation of China (51104105).