Study on the Acoustic Emission Characteristics in the Rupture Process of Medium Grain Sandstone with Natural Structural Plane

In order to study the acoustic emission characteristics in the rupture process of medium grain sandstone with structural plane,the basic top sandstone of 22307 working face in Bulianta Coal Mine was taken as the research object.The tests of direct tensile,direct shear and uniaxial compressive were carried out for the intact medium grain sandstone and medium grain sandstone with natural structural plane respectively.The influence of natural structure on the acoustic emission characteristics was analyzed,the results showed that：in the process of direct tensile test,the structural plane has a significant influence on acoustic emission characteristics.The peak count of intact medium grain sandstone is 13.5 times of the structural plane medium grain sandstone,and the cumulative count of medium grain sandstone with structural plane is 3.2 times of the intact medium grain sandstone; in the process of direct shear test,the structural plane also has some influence on acoustic emission characteristics.The peak count of intact medium grain sandstone is 2.4 times and 0.5 times of the structural plane medium grain sandstone respectively; in the uniaxial compression test,the structural plane has no influence on acoustic emission characteristics,the acoustic emission peak count and cumulative count are almost unchanged.