2005 Volume 121 Issue 12 Pages 576-582
A tensile strength deduced from a hydraulic fracturing stress measurement is different from tensile strengths obtained by a Brazilian test and by a bending test. In this paper, the authors discussed the differences based on a probability theory of fracture considering stress distribution in the specimen. At the first, they conducted the three tests in specimens of Kurokami-jima granite, and suppose that variation of their tensile strengths follows Weibull distribution. At the second, from ratios of tensile strengths among the hydraulic fracturing, the Brazilian test and the bending test, they found that Weibull's coefficient of uniformity, m, equals to 10.1. At the third, they elucidated that the obtained coefficient of uniformity is good for a significance level in the Kolmogorov-Smirnov test.
Through the discussion, it is concluded that the differences of the tensile strengths among the hydraulic fracturing, the Brazilian test and the bending test can be explained to some extent by the probability theory of fracture.
