MODEL TEST OF THREE-BORE METRO STATION CONSTRUCTED WITH THE METHOD OF EXPANDING SECTIONAL SHIELD TUNNELS

The construction scheme of the metro station was studied through similar model tests. The metro station is a three-bore structure constructed using the panding method based on shield tunnels. Results show that the construction scheme of the metro station is feasible. But it is necessary to reinforce the surrounding rock of the vault of tunnel arches during the expanding construction. The vertical displacement of the surrounding rock displays a “U” shape distribution after the expanding construction. The displacement of surrounding rock increases if the surrounding rock of the vault of tunnel arches is not reinforced. The settlement curve of the ground surface is approximately normally distributed, and the influencing breadth is 3B, where B is the breadth of the three-bore structure.