Abstract: To constitute the highway tunnel support system to direct the safe tunnel construction for all surrounding rock sub-classifications, based on the sub-classification method standard, the physico-mechanical parameters and characteristics of the double lane highway tunnel, the excavation methods, assistant measures, structure forms, support types and primary lining parameters for all sub-classifications have been ascertained by theoretical analysis, example statistics, numerical calculation. The results show that the full face excavation method and light load bearing support are fit for the rock class Ⅲ1, the bench cut method and medium load bearing support are fit for the rock class Ⅲ2; the bench cut method and heavy load bearing support are fit for the rocks class Ⅳ1, class Ⅳ2, class Ⅳ3; and the assistant measures which can raise the surrounding rock strength in reinforced area to the level of rock class Ⅳ1 are needed for the rocks class Ⅳ2 and class Ⅳ3; the bench cut method and the assistant measures which can raise the surrounding rock strength in reinforced area to the level of rock class Ⅳ1 are fit for the rock class Ⅴ1; the center cross diagram method and the assistant measures which can raise the surrounding rock strength in reinforced area to the level of rock class Ⅳ3 are fit for the rock class Ⅴ2; the center diagram method and the assistant measures which can raise the surrounding rock strength in reinforced area to the level of rock class Ⅳ1 are fit for the rocks class Ⅴ1 and class Ⅴ2; and the special load bearing support is needed for them; the inverted arch should be built for the surrounding rock sub-classifications from class Ⅳ1 to class Ⅴ2 .

Key words: tunnel, surrounding rock sub-classification, excavation, support design parameters