DEFORMATION THEORY OF GRANITE ROCK TUNNEL CONSTRUCTION BASED ON SUBDIVISION OF THE ROCK GRADE

The present research stage grade of surrounding rock sub classification in construction is a hot spot in surrounding rock, the purpose is to solve the current classification of surrounding rock of large span can not meet the actual needs of the construction difficulties. Subdivision scheme of surrounding rock during construction stage level tend to develop specific engineering geology based on the background, so there will be more limited in scope, but the segmentation mechanism is universal. In the city the rapid development today, the subway to alleviate traffic pressure, improve the city traffic mode of excellent radiation force in the construction of large and medium-sized city. In order to better guide the subway tunnel construction, fully consider the characteristics of city subway tunnel construction, typical granite strata in Qingdao subway construction of the engineering geology background, by using numerical simulation software FLAC3D, the simulation of surrounding rock in different surrounding rock mass surface in shallow strata of different depth under the settlement to evaluate the stability of surrounding rock, stability difference the surrounding rock based on Ⅲ, IV, V rock corresponding subdivided into 2, 3, and 3 sub classes.