Construction schemes for large excavations near subway facilities

A large excavation in Guangzhou is taken as an example. Through the spatial relation between the excavation and subway tunnel, the control factors during its construction are introduced. By discussing their advantages and disadvantages, the feasibility of different excavation sequences is studied. A 3D finite element model is established to evaluate the effect of the excavation on the subway tunnel due to different construction schemes. The results indicate that the construction process the excavation should start from the section far away from the subway tunnel to avoid disturbing the soil surrounding the tunnel. Fort the construction over subway tunnel, the piecewise and block excavation method is favorable for controling the subway tunnel. For the construction at both sides of subway tunnel, the eccentric earth pressure due to unbalance excavation should be considered.