Experimental Study On The Gas Ignition Caused By Instability And Rudding Of Hard Quartz Sandstone

The hard quartz sandstone roof and gas are common in Chinese coal mines.The instability mechanism of hard quartz sandstone and the bursting mechanism of gas in goaf have not been completely clear.Hence,study on the instability friction effect and the factors affecting the gas deflagration of the hard quartz sandstone,and the mechanism of the accident are important for the safe production.In this thesis,the mechanical stability of the overlying strata is analyzed.Taking into account the factors that affect the fracture angle,the stability formula of the roof including the fracture angle is deduced.The function curve of the function is drawn by Matlab mathematics software,and the change trend of the function under the condition of the fracture angle and the rotation angle is analyzed.The effect of the addition of fracture angle on the stability of the overlying roof was studied.Taking hard quartz sandstone as the main research object,we independently designed experimental equipment and formulated experimental programs.The phenomenon of indoor rock friction experiments under different friction speed,gas concentration and rock interface pressure was compared.The influence of different factors on the ignition of gas by frictional effect of rock was analyzed.The influence of different factors on the ignition of gas by frictional effect of rock was analyzed.The law of rock friction effect under different influence factors to ignite gas was studied.Using 3DEC numerical simulation software,three-dimensional numerical models of different roof thickness and different working surface widths were established.Study the variation law of shear stress at each measuring point during the mining process.Distinguish the probability that the measurement point corresponds to the unit block body slipping instability.The situation and timing of sliding instability of the measuring point are analyzed.The effect of the length of the working face and the thickness of the top plate on the area where the rock formation in the goaf slips and falls is determined.It has guiding significance for the safe production of coal mines.