BEHAVIORS OF CRACK PROPAGATION OF ROCK-LIKE MATERIAL WITH DIFFERENT JOINTED THICKNESS

To better understand the interaction of joints and its effect on the mechanical behavior of jointed Rock-like material models, the results of a physical experiment program undertaken in the laboratory were present in this manuscript. This experiment used the physical simulation method to study the mechanical and acoustic properties of specimens. The ratio of cement: sand (quartz stone): water = 1:2:0.5 respectively was used to make 100 ×100×100 mm of jointed cubic specimens. Based on the uniaxial load test of a single jointed rock mass model, the relationship between the jointed thickness and the peak strength is obtained. The result shows that the peak strength decreased with the increase of joint thickness. At the same time, by using acoustic emission on fracture procession and digital photographic analysis, obtained acoustic emission events localization and fracture propagation characteristics in jointed rock mass with the different joint. It is found that in different stages of the stress-strain curve, the acoustic emission signals show the varying degrees of intensity. At the beginning of plastic deformation and strain softening propagation, the ring-down counting will be suddenly increased and the cluster location depends on the joint. The failure modes of the specimens with different jointed thickness were mainly the splitting failure and partial shear failure. Keyword: Joint thickness, Acoustic Emission, Failure mode, Ring-down count