Review on the buoyancy effect of the multi purpose double-deck tunnels during operation

Double-deck tunnels beneath the groundwater table have relatively large volume and commonly constructed as watertight tunnels. In this case, it requires to secure stability of the tunnels for buoyant force. Generally the contact fo rce between lining and ground is sufficient to resist the buoyant force. However in the long-term the contact force could be reduced because of structural deterioration. In this study the effect of long-term buoyant force acting on the double-deck tunnel is investigated. The result s has shown that the buoyant force has increase d invert deformation and stress. It is indicat ed that the contact resilience between lining and ground needs to be kept during tunnel operation.Keywords: Double-deck tunnel, Lining, Buoyant force, Stress-pore pressure coupled analysis, Ground stiffness : . . . . . . . : , , , - , Copyright ⓒ2015, Korean Tunnelling and Underground Space Association