A round robin test on tunnels under seismic actions

Centrifuge modeling is definitely an alternative powerful tool to produce artificial case histories' for calibration, back-analysis or benchmarking among different analytical approaches. This paper outlines the main features of RRTT, a Round Robin numerical Test on Tunnel centrifuge models, organized by the Authors and jointly promoted by three Technical Committees of ISSMGE. Although it is quite difficult to measure such increments of internal forces during real earthquakes, centrifuge modeling allowed an experimental assessment of these quantities during artificial seismic events; the results may be used for benchmarking simplified to complex prediction methods. The main instrumented section was located at the mid-span of the tube and a second section 50 mm aside. The strain measurements on the tube were purposely performed in two sections, in order to check that no boundary effects occurred and the plane strain conditions were ensured.