Fracture behavior of Dingziwan granite with Cracked Straight Through Brazilian disc specimen by two splitting loading methods

摘要

The fracture mechanical behavior of Dingziwan granite was investigated with two splitting loading methods.The granite was taken from Dingziwan zone of Hunan Province, a famous granite area in China.Model I fracture toughness tests were conducted with Cracked Straight Through Brazilian Disc specimen (CSTBD) by MTS Landmark testing machine.In the work, two splitting Brazilian loading methods according ISRM standard (method I) and China standard (method II) were employed.The difference between the fracture mechanical behavior of method I and II were very apparent.For fracture time or fracture displacement, the results of method I are large than that of method II.And the fracture toughness of method I is 1.01 MPa·m1/2, which is about 42％ higher than that of the method Ⅱ (0.72 MPa·m1/2).Excluding the subtle effect of loading rate, the main reasons for above difference of two methods were also discussed.The linear relationship between fracture toughness and fracture displacement was obtained based on the actual measuring data, which provides a valuable understanding for the crack arresting problem.