A power flow analysis of a double-deck circular tunnel embedded in a full-space

• An analytical model for a double-deck circular tunnel is developed.
• The receptance method is used for obtaining the structure response.
• A power flow comparison against a simple tunnel is performed.
• Clear differences in the radiation patterns and maximum values are found.

The purpose of the present investigation is to obtain the mean power flow radiated by a double-deck circular tunnel and compares it to the one radiated by a simple circular tunnel. To achieve this, a harmonic line load is applied on the interior floor of the first one and at the bottom of the second one. For the double-deck tunnel, a new analytical model based on the receptance method is developed. The proposed model describes the dynamics of the interior floor using the thin plate theory and considers the Pipe in Pipe (PiP) model to describe the tunnel and soil coupled system. Plain strain conditions are assumed for both systems and conservative coupling is considered between them. Numerical results show significant differences between the power flow radiated by both tunnels, with the one radiated by the double-deck tunnel reaching much higher values. The effect of modifying the flexural rigidity of the interior floor is also presented.