Abstract:The surrounding rock classification is under discussion in the code for design of highway tunnel,and it can not satisfy the construction requirements. Therefore,the subclassification of surrounding rock is performed. Based on the subclassification,the physico-mechanical indices of rock subclassification are achieved. Firstly,based on the subclassification methods,the combination of rock masses with different hardnesses,tectonic structural planes and structural planes combination degree is presented. Numerical experiments on every combination are also performed. Using the experimental results,in-situ investigation and statistical analysis,certain physico-mechanical indices of subclassification rock mass are gained. As for the soil surrounding rock,two ways,i.e. field test and investigation,and statistics analysis,are employed to evaluate the physico-mechanical indices of surrounding rock masses;and then,the laboratory physico-experimental results are combined to determine the actual physico-mechanical indices of soil surrounding rock masses.