Research Of Coal And Rock Damage Weakening Under The Action Of Water Pressure

China coal reserves is one of the richest countries on the world, coal energy plays an important role in the development of national economy, with the coal resources exploitation strength increasing, coal mining efficiency has been paid more and more attention. Aqueous to coal and rock damage weakening is the important topic of coal mining process, Because China's coal seam widely distributed, research the regularity of coal and rock damage to weaken under the action of water pressure is one of the important topics In steep coal seam mining method optimization.Based on the water pressure of coal and rock damage effect to coal and rock damage weakening as the main research object. First, through the physics experiment of aqueous to coal and rock mass strength damage reduction, get the relationship of the solution to the moisture content of different coal and coal rock strength changes, the elastic modulus and poisson ratio and the moisture content, Tests show: coal rock strength and elastic modulus decreases with the increase of the moisture content, petrographical poisson ratio increases with the moisture content; Secondly, summarizes the solution of coal and rock mechanics properties in three factors: Stress and strain characteristic, coupling of strength and solid-liquid. From angles of coal tiny intensity obey Weibull distribution and density, elastic modulus variation, establish statistical damage model of the axial compressive and pressure under the joint action of coal and rock. Introduced the pore water pressure influence factor, proof damage of pore water pressure to coal and rock. Using the theory of hydraulic fracturing to analyze the principle of pore water pressure effect to coal and rock, get coal and rock crack splitting strength value, and describe the coal and rock porosity, Finally, using the F-RFPA2D numerical simulation and analysis the pore water pressure to coal and rock damage process, influence to coal and rock deformation, Research shows that:When the pore water pressure constant, coal rock strength is increasing with confining pressure increases; When the same confining pressure, the higher of pore water pressure is, the lower of coal rock strength. Confining pressure size and size of water pressure on initial pore water pressure effect significantly.