Time analysis and program optimization of form removal of tunnel lining structure

The tunnel lining structure is a time-dependent structure system during construction period. Its removal time directly impacts the schedule, the quality and the structural safety of the tunnel. Combining with the bend segment instance of underground diversion tunnel of the Three Gorges Project power station and by analyzing the small-age concrete strength and elastic modulus variation during the coagulation, the study simulates the "anti-anchor" effect of system bolt in tunnel secondary lining and uses numerical simulation to analysis the tunnel lining structure stress and displacement under the different tunnel lining conditions of large face tunnel lining on the complex conditions. The results show that the appropriate form removal time of tunnel lining structure is between 24 hours and 48 hours. From the position of shortening the period and the construction safety, optimized the project of tunnel lining and make suggestions.