Study on the Optimization of Support Parameters of Metro Station Constructed by Arch Cover Method

The arch is the main stress structure of metro station in the construction of arch cover method. The preliminary geological survey has some limitations, and the arch structure design based on the survey results is usually too conservative, which increases the investment cost. Therefore, it is necessary to optimize the design parameters of arch structure. In this paper, based on particle swarm optimization (PSO) algorithm, the engineering cost is taken as the optimization objective, and the monitoring control values of displacement are taken as the constraint condition. The scheme optimization is carried out for the thickness of outer primary lining and inner primary lining and removal length of temporary support. The final optimization values of parameters obtained by PSO algorithm are that the removal length of temporary support is 18 m, the thickness of the outer primary lining is 22 cm, and the thickness of the inner primary lining is 26 cm. Compared with the original design scheme, the engineering cost of the optimized scheme is reduced by 8.79%. The optimized parameters can not only meet the safety requirements of the project, but also effectively reduce the project cost, which has guiding significance to the actual project construction.