Abstract: The shear strength parameters of rock mass have the characteristics of randomness of fuzziness. This paper presents an approach of determination of the rock mass shear strength zone based on symmetric triangular fuzzy numbers. The rock strength parameters are determined through the least absolute linear regression. This method not only can reflect the uncertainty of the shear strength parameter, it but also can reduce the impact of abnormal data on the data fitting results. This new approach has the advantage of simple calculation and easy to use. A case history of rock mass shear strength parameters determination is presented in the paper.

Key words: Shear Strength of Rock Mass, Symmetric Triangular Fuzzy Numbers, Least Absolute Linear Regression, Data Fitting