Study On The Influence Of Creep Effect Of Surrounding Rock On The Long-term Stability Of Tunnel Lining

In recent years,the tunnel construction in our country is booming,the mileage under construction and the mileage in operation of the tunnel are showing explosive growth,which has provided a very strong impetus for China’s economic development.But in the process of tunnel development,there are also some problems that the former tunnel workers Pay less attention to.In the short period of time(five years)after the completion of some tunnels,there are some structural damages,which are far from the service life of the tunnel design.However,the investigation of these tunnel diseases and the subsequent development are carried out to detect these diseases Most of the damages are time-dependent,and the creep of surrounding rock has a great influence on the failure process of tunnel structure.Therefore,this Paper studies the influence of creep effect of surrounding rock on the long-term stability of tunnel lining.The main work of this Paper is as follows:(1)The typical cases of tunnel diseases with obvious creep effect are collected,and it is concluded that the occurrence time of the disease is relatively short com Pared with the service life of the tunnel,which is about five years.The main forms of the disease are longitudinal cracks,circumferential cracks,Partial block falling,etc.the location of the disease is mainly the side wall,the arch waist and the arch foot.The treatment plan of the disease is only to re Pair the cracks,reinforce and replace the lining.(2)The viscoelastic solution of circular tunnel is analyzed by using the knowledge of viscoelasticity.In order to reflect the characteristics of attenuation creep in the surrounding rock of tunnel,Maxwell creep constitutive model modified by Bailey Norton creep equation is used in the analysis.(3)Combined with a tunnel in Shanxi Province,this Paper studies the lining diseases caused by creep of surrounding rock,reveals the causes of tunnel lining damage,and simulates the treatment process of lining removal and replacement after the tunnel structure damage caused by creep,so as to evaluate the effect of the treatment scheme.(4)Three kinds of different lining forms are simulated to evaluate the performance of different lining forms in resisting the tunnel damage caused by the creep of surrounding rock.It is found that the performance of circular lining structure and that of lining structure with small radius of curvature is better than that of lining structure with small radius of curvature.