Failure Mechanism and Mechanical Characteristics of Rockmass Containing Close Intermittent Joints under Plane Stress Condition

Biaxial compression model tests on rockmass containing intermittent joints under plane stress condition were carried out in this study, where the laser speckle photo technique was used for measuring the displacement field. The results obtained have indicated that the laser speckle method was effective and the measuring value was about 14% less than the measuring value of dial gauges. Based on the displacement field and the principal stress field which were measured by laser speckle photo technique, dial gauges and strain gauges, the angle of wing incipient crack, the evolution of stress field at the joint tip and the path of crack extension were deeply studied. The deformation and failure characteristics, including the fracture mechanism of rockmass, were also analyzed in this study.