Abstract: The doublesidedrift method used in the mining construction of metro stations with superlarge crosssection has many disadvantages, such as slow construction speed, inconvenient operation of construction machinery, and high construction risk coefficient. To address these problems, a case study is conducted on mined Wulidian station of Chongqing metro line 9 with superlarge crosssection. 〖JP2〗Then, the traditional doublesidedrift method is optimized by changing the excavation sequence, adjusting the support form of core soil to the straight wall type, reducing the number of temporary braces and modifying the construction time, and setting up assemble and reusable temporary vertical support. Furthermore, the numerical simulation analysis and site construction effect analysis are carried out regarding the optimized construction method. The results show that the recommended method can effectively control the deformation of surrounding rock, improve the construction efficiency, and reduce the construction risk and cost in stable stratum without rich water. The construction period and cost of the project are reduced by 1 month and RMB 1.8 million yuan, respectively.

Key words: superlarge crosssection mined metro station, doublesidedrift method, construction optimization, temporary support, numerical simulation