Abstract:

Xinggong Street station of 203 bid section of the 1st phase of Dalian Metro is constructed by bottomup mining method. The excavation crosssection area of the station tunnel is 343.8 m2 and the thickness of the cover of the station tunnel ranges from 7.1 m to 11.1 m. During the construction of the station tunnel, technologies, including installing advance large pipe roof + small duct at the arch of the station tunnel, adding the second layer of the primarysupport and longitudinal beam, improving the rigidity of the arch support structure, using side wall anchor to protect the stability of the straight walls, adopting sixstep doublesidedrift method for top heading excavation, adopting bench cut method, adopting vertical loosening blasting method and smooth blasting method for the central and lower part excavation, are used, so as to control the settlement and deformation of the ground surface, the underground pipe lines and the surrounding buildings, to guarantee the stability of the support structure and to prevent collapse of the working face and the tunnel. In the end, the influence on the stability of the support system of the arch is reduced, and the construction safety is guaranteed.

Key words: complex ground, shallow cover, mining method, largespan Metro station, arch shell, doublesidedrift method, bench method, blasting, anchor cable