Mechanical characteristics and fracture mechanisms of fissured rock mass samples with various opening sizes

To obtain the effect of fracture failure mechanics characteristics and behavior brittle rock masses on compound factors fissure openings inclination, uniaxial loading tests were performed single-fissured rock-mass specimens with different using a test machine. The results show that increase in openings, fissured peak strength variation inclination angle changes from first decreasing then increasing to gradually increasing, at minimum value shifts 45° 0°. At same angle, mass decreases opening size. greater size prefabricated fissure, smaller influence angle. elastic modulus specimen shows positive correlation negative Combined neighborhood stress field analysis open tip, criterion composite under tension is established, linear relationship between intensity KI KII verified. fissures shear also identified, which based factors.