CT REAL-TIME SCANNING TESTS ON SINGLE CRACK PROPAGATION UNDER TRIAXIAL COMPRESSION
LI Tingchun,LU Haibo
(Shandong Provincial Key Laboratory of Civil Engineering and Disaster Prevention and Mitigation,Shandong University of Science and Technology,Qingdao,Shandong 266510,China)
Abstract:The propagation law of the single crack under triaxial compression is systematically studied through the CT real-time scanning tests. In the tests,through comparison of similar physico-mechanical parameters to the real rock,ceram is selected to precut the test specimens. From the comparative analysis of CT values,CT variances and CT images in different manifold areas,the damage evolution processes,such as the courses of compressed crack,self-similar propagation,wings growth,microcracks propagation,accelerated crack growth and the damage evolution of the specimen failure,of the crack is accurately obtained as follows:the test results show that under triaxial compressive stresses,the crack is obviously compressed at first;then,the propagation of wing crack is restricted,and the self-similar propagation is enlarged by comparison with the uniaxial test result and the propagation of wing crack starts from the edge of self-similar propagation. In conclusion,the propagation of initial crack is influenced obviously by the confining pressure,which makes it slower and similar to ductile failure.