Numerical Analysis of Twin Tunnels Lining under Different Seismic Conditions

The last seismic events showed that tunnel lining may suffer extensive damage. Employing numerical modeling has a great importance in predicting the performance of tunnels. This paper tests Zaouit Ait Mellal (ZAM) twin tunnels located between cities Marrakesh and Agadir Morocco. Dynamic analysis was adopted by FLAC 2D software using finite-difference elements. Four soil cross-sections were chosen, with different support devices installed along tunnels, such as rock bolts steel ribs. signals introduced input obtained from three earthquakes: Al Hoceima 2004 Morocco, EL Centro 1940 USA, Kobe 1995 Japan. results show deformation is more noteworthy sections ribs compared to those bolts, which observed large values relative displacement, reaching 1020 (mm) 2.29 × 105 (N.m/m) maximum bending moment. indicates these present higher vulnerability during an earthquake, should be considered when looking at overall safety tunnel.