Abstract: The disease of secondary lining thickness lack directly reduces the reliability of tunnel structure.Taking a certain tunnel as the research object,the secondary lining thickness lack at its left line and right line were treated,and statistical analysis on the diseases was made from two aspects of variation of longitudinal mileage,and different positions of cross section.The numerical analysis software was used to numerically simulate the stress of lining structure and to verify the performance of treatments,aiming to provide some references for treatment of tunnel lining disease.The main achievements were listed as follows:①On the cross-sectional position,the most serious disease of lining thickness lack is in the position of vault,and the defect rate decreases sequentially from the vault to hance,and then to arch foot.②In the longitudinal mileage,there are a lot of sections with more serious disease of secondary lining thickness lack,including the section of ZK125+400~ZK125+800 at vault of left line,ZK126+200~ZK127+200 and ZK127+400~ZK128+200 at hance of left line,as well as the section of K125+900~K127+800 at vault of right line,K125+400~K126+400 at left hance,K126+600~K127+600 of right hance.So it is suggested to strengthen the monitoring of tunnel lining quality.③The variation of internal force and safety factor of lining structure before and after its treatment on secondary lining thickness lack were grasped,showing that there is a significantly increase in the bearing capacity of lining and in the safety factor of the hance and the arch foot,which is beneficial to the force of tunnel side wall.It proves that the treatment is effective.

Key words: Tunnel, Secondary lining, Contrast and analysis of disease, Numerical simulation, Internal force and safety factor of lining