In the Hoek-Brown criterion

many factors affecting rock failures are considered and the nonlinear failure characteristics can be described more accurately. It is known that the uncertainty of rock parameters seriously affects the application of the criterion. Using the sensitivity analysis and the displacement equation of surrounding rocks

the nonlinear regression method(NLRM) has been proposed for the analysis of the rock parameters of the Hoek-Brown criterion. In developing the above mentioned method

the uniform design and FLAC3D software are used. And we develop a reasonable back analysis method and procedures by leading into the differential evolution. The method is successfully used to analyze the stability of the tunnels in Qingdao metro. Results show that the NLRM can better reflect the relationship between the parameters geological strength index(GSI)

agitating coefficient D

Poisson’s ratio and the displacements of tunnels. It can be concluded that the analytical results are very good agreement with the monitoring ones. The proposed method can be used for obtaining the parameters of the Hoek-Brown criterion accurately.