Abstract:

A mined station and the connecting line secondary lining of Shenzhen Foreign Languages School Station on Shenzhen Metro Line No. 8 are characterized by super large crosssection, complex dismantling technology and difficult construction organization. To overcome these problems, the lining face in tunnel is optimized to 4 to reach smooth construction organization based on construction organization of 7 working faces and the castinplace scheme of vertical multilayer support and considering the construction site conditions, schedule node arrangement and construction organization mode. And with the application of large crosssection secondary lining trolley, the number of vertical layered pouring and the workload of support formwork has been reduced, and the overall construction progress has been accelerated. Finally, based on the finite element numerical simulation, the deformation law of the supporting structure in the whole process of excavation, demolition of temporary support and construction of secondary lining of the super large crosssection mining project is analyzed, and the analytical results coincide with the actual conditions well, indicating that the deformation is within control. By optimizing the construction organization and adopting the secondary lining trolley, the construction progress has been greatly improved on the premise of ensuring safety and quality, the construction period has been saved by 52 days, and the construction cost has been reduced by RMB1.15 million yuan.

Key words: super large crosssection, metro station, connecting line, mining method, temporary support demolition, secondary lining