Rock strength interval analysis using theory of testing blind data and interval estimation

The concepts of rock strength intervals are presented in this work, furthermore, central values of intervals and their corresponding credibility are provided using two-case study based on blind data theory and fuzzy interval estimation. 60 granite specimens are first tested, the compressive strength interval and tensile strength interval are [ 103.68, 219.6 l ] and [7.53, 11,86] MPa, while the tested mean values of compressive strength and tensile strength are 152.86 and 10.14 MPa, the credibilities are less than 58.4% and around 70.4%, respectively, the credibility of shear strength is between 40% and 60%. Then 70 other rock specimens are designed and tested, the similar conclusions can be reached. The results show that the conventional definite values are the particular values within the intervals, and the credibility of them often fails to reach the high-precision engineering requirement. The results demonstrate the feasibility and application potential of this proposed algorithm for the engineering practice. The references for engineering value selection of rock strength under different credibility or according to frequency distribution of central values are provided to increase the reliability and precision of calculation.

The concepts of rock strength intervals are presented in this work,furthermore,central values of intervals and their corresponding credibility are provided using two-case study based on blind data theory and fuzzy interval estimation.60 granite specimens are first tested,the compressive strength interval and tensile strength interval are[103.68,219.61]and[7.53,11.86]MPa,while the tested mean values of compressive strength and tensile strength are 152.86 and 10.14 MPa,the credibilities are less than58.4%and around 70.4%,respectively,the credibility of shear strength is between 40%and 60%.Then 70 other rock specimens are designed and tested,the similar conclusions can be reached.The results show that the conventional definite values are the particular values within the intervals,and the credibility of them often fails to reach the high-precision engineering requirement.The results demonstrate the feasibility and application potential of this proposed algorithm for the engineering practice.The references for engineering value selection of rock strength under different credibility or according to frequency distribution of central values are provided to increase the reliability and precision of calculation.