The Study And Application Of Physical Simulation Test Of The Evolution Law Of Overburden Rock Fracture Under Multiple Factors

Affected by mining,the overlying strata will move and break,and a large number of gasses will be released by the pressure relief and accumulate in the vicinity of the fracture area.Studying the rules of the evolution of overlying strata in mining rocks provides a theoretical basis for the arrangement of mine gas drainage systems,especially Due to the current complex and varied geological conditions in China's coal mines,it is extremely urgent to study the evolution rules of cracks in mining overlying rocks under multiple factors;and physical similarity simulation experiments can reproduce the mining stope better,which is the evolution process of overlying rock fractures.The study of the distributional state provides strong theoretical support.Based on the laboratory two-dimensional physical similarity simulation testbed,the paper developed a physical similarity simulation testbed for the fracture evolution of overlying strata covered by two-dimensional variable-angle mining,and used the self-developed two-dimensional variable-angle mining to study the physical similarity of rock fracture evolution.The simulation test rigs studied the variation of subsidence,broken coefficient,separation and penetration parameters under various factors such as mining height,propulsion speed and inclination,and determined the compaction zone and fracture zone of mining overburden fractures.The relevant parameters provide a theoretical basis for the extraction of pressure relief gas.At the same time,according to the fractal theory,the fractal rules of the whole area of cracks in mining overburden,the fissure area and the compaction area are studied,and a comprehensive model of the crack evolution of overlying strata under mining is established.Based on the actual conditions of the coal mine site and the principle of gas drainage,combined with the evolution law of cracks in overlying strata,the field layout parameters of the high-drainage laneway are determined,and the gas drainage effect is analyzed to ensure the gas drainage of the high-drainage roadway.The rationality and multi-factor study on the evolution rules of cracks in mining overlying strata provide a powerful theoretical basis for the current safety production of coal mines.