Aiming at the compression-shear damage type perilous rock, I establish a uniaxial compression test indoor to research how different inclined angles’ and lengths’ of main structural plane impact on the fracture critical stress of test sample and propagation path of crack. The study shows that: when main structural planes of samples have the same length, the fracture critical stress of test sample increases along with the increasing of main structural plane’s inclined angle; when main structural planes of samples have the same inclined angle, the fracture critical stress of test sample decreases along with the increasing of structural plane’s length. The branches of crack include wing crack, collinear crack and inclined crack. The collinear crack appears frequently, the wing crack follows and the inclined crack appears rarely. In addition, the wing crack’s propagation angle relatively conforms to the angle of maximum circumferential stress criterion. According to experimental research on main structural plane tip propagating in compression-shear damage type perilous rock, I acquire regularity which has positive significance to further study on main structural plane tip extending in other types of perilous rock.
perilous rock, compression-shear damage, main structural plane; model test, crack condition
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