Abstract: Having elaborated the importance of study on rock mechanics parameters, we introduced the principles and methods of determining rock mechanics parameters by Hoek-Brown criterion. The mechanical parameters of soft-hard interbedded rock slope at Pengjiawan of Yichang-Badong expressway are taken as research example. On the basis of physico-mechanical parameters, rock integrity factor and wave velocity obtained from laboratory test, we reduced the physico-mechanical parameters by Hoek-Brown criterion. Comparative analysis on the results suggest that the shear strength parameters determined by linear regression analysis and non-linear fitting method are both logical; the numerical simulation result is consistent with the deformation and failure characteristics of actual rock. The results provide guidance for the determining of rock mechanics parameters in other similar projects.

Key words: rock mechanics, mechanical parameters, Hoek-Brown criterion, wave velocity of rock mass, numerical simulation