Analysis Of The Stability For The Surrounding Rock Of Large Span Tunnel

With the rapid development of the highway and subway construction, there are more and more tunnels, especially large-span tunnels. In the course of the tunnel's construction, the stress in rock mass will redistribute around grotto,When this kind stress exceeds surrounding rock's ultimate strength, surrounding rock will lose its stability and destruct. Consequently, it becomes increasingly important for the study of stability of surrounding rock during the construction of tunnels.Based on a great deal of material,this thesis discusses the theories analysis process of the surrounding rock. Aimed at the characteristics of the stability of the surrounding rock, analysis the main factors to affect it's stabilty, on this basis,select the factors of different excavations that affect to the surrounding rock stabilty deeply, make use of the ANSYS procedure carry on the numberical imitation to combining the concrete engineering,and analyse the stress field and the displacement field of the surrounding-rock draw a conclusion that by take reasonable excavation methods and support measures will be enough to ensure the stability of surrounding rock. The construction monitoring is the most important part during the construction of tunnels, based on the analyse the basic measured items and the currently stability standard of the surrounding rock, get some beneficial conclusions. As to the character that the tunnel arch crest sink is the view body of the tunnel surrounding rock mechanics behavior,and also to the most important item, through anlysis of the measured result of the arch crest sink ,draw the conclusion that the stability of the surrounding rock.