Abstract:

Zhongshan Park Station of Line 3 of Qingdao Metro, which is located in heterogeneous ground, is constructed by archcover method. In the paper, the excavation of the left, central and right pilot tunnels of the upper section of the Metro station, as well as the construction of the archcover and the excavation of the lower section of the Metro station, are analyzed by means of numerical simulation and by comparing with the measured data, so as to summarize the rules of the transverse and longitudinal settlement of the ground surface induced by the pilot tunnel excavation. Conclusions drawn are as follows: the influence scope of the pilot tunnel excavation is 12 m ahead of the tunnel face, the transverse influence radius of the excavation the upper section is 1.5 times of the staion diameter, and the excavation of the upper section and the conversion between the archcover and the flexible support are the main causes for the settlement. Furthermore, key countermeasures and empirical ground surface settlement formula are proposed for similar Metro stations in the heterogeneous ground in Qingdao.

Key words: Qingdao Metro, Metro station, archcover method, settlement rule, numerical analysis