Abstract: To ensure the safety of the excavation of connected aisle in a cross-river tunnel by directly looking into the mechanical features of freezing soil curtain and the impact of the excavation on the curtain, large finite difference software FLAC ^3D is employed to numerically simulate the excavation process. Through the simulation, the stress and deformation of the freezing curtain are analyzed and its safety is evaluated. Moreover, the stress and displacement distributions of the curtain are further analyzed in detail. The designed thickness of the freezing soil curtain is determined to be safe at 2.5 m , which meets the construction requirements. It is also pointed out that the contact location between the freezing soil curtain and the tunnel should be given more concern as it is easy to see stress concentration because of quick heat dissipation during the freezing with unsatisfactory freezing effect. The study can serve as a reference for the artificial freezing technique and the numerical simulation of connected aisles.

Key words: connected aisle , freezing method , numerical simulation , freezing soil curtain , FLAC ^3D