Mechanical Properties of Shear Strength of Coal and Rock at Different Rates

We carried out experimental study on mechanical properties of shear strength with different rates of 9^#, 10^#, 11^# coal rock samples in Fenxi Gaoyang Coal Mine, the results show that the shear strength of the coal and rock in the area decreases with the increase of shear rate at 45 °and 55°, and increases at the shear angle of 65 °. The peak of shear strength of coal and rock increases with the increase of normal stress. The relationship between shear peak strength and normal stress is linear. Under 0.001 mm/s rate, the cohesion of coal rock is 1.52 MPa, the internal friction angle is 36.46°, and the cohesion is 2.44 MPa and 2.35 MPa at 0.01 mm/s and 0.1 mm/s rate, and the internal friction angle is about 25.59°and 32.37°.