FEM Modelling of the Seismic Behavior of a Tunnel-soil-Aboveground Building System: A Case History in Catania (Italy)

In the design of tunnels it is extremely important to assess the possible damage to the tunnel and to the aboveground structures in order to provide adequate mitigation measures, above all in high seismic hazard areas. Great attention has been devoted to separated tunnel-soil interaction analysis and soil-aboveground structure interaction analysis. Unfortunately, studies involving tunnel plus soil plus aboveground structures (full-coupled analysis) are still very rare. The present paper deals with the seismic response of a tunnel-soil-aboveground building system. The effects of the tunnel on the response of the soil and/or of the building and vice versa have been analysed by means of a full-coupled FEM modelling. A cross-section of the recently-built underground underground in Catania (Italy), including an aboveground building has been analysed and considering the expected scenario earthquake. Results are reported in terms of amplification ratios, frequency ratios, as well as dynamic bending moments in the tunnel. The main goal of the paper is to highlight the combined effect of tunnel and aboveground structure.