Seismic Response of Underground and Floating Tunnels

The use of floating tunnels and underground tunnels is currently seen as an alternative solution for transportation problems in large cities. Both floating and underground tunnels require safe designs that must include seismic effects. In recent decades, the seismic amplifications on canyons, valleys, and underground tunnels have mainly been studied, attracting the interest of engineers and researchers, with little focus on floating tunnels. However, it has been reported that almost 90% of natural earthquakes have epicenters in offshore areas, where floating tunnels and other marine structures are being installed. In this paper, the use of the indirect boundary element method (IBEM) is proposed for the calculation of seismic amplification in the weak parts of floating and underground tunnels. The results show evidence of diverse important factors which are involved in this type of problem, such as the kind of seismic waves, i.e., compressional and distortion waves, type of soil, and angle of incidence of the seismic wave.