Preliminary Study on the Phenomenon and Mechanism of Granite Core Discing in Laboratory Drilling Test

It is generally believed that core discing a rock failure phenomenon under high in-situ stress, and stress closely related to the characteristics of discing. The drilling tests intact granite were conducted on laboratory servo-controlled test platform. was observed showed at rate (> 15 mm/min) no confining pressure (0 MPA). fluctuation parameter consistent with section along core. mode discs determined by morphology surface fractal dimension characteristics. Numerical simulation models considering interaction between drill bit established using ANSYS software. Based tests, analysis discs, numerical simulation, mechanism low as follows: Tensile caused concentration root. critical factor affecting