ABSTRACT
Some of cut-and-cover tunnel structures in Kobe area had suffered seismic damage due to 1995 Hyogo-ken Nanbu earthquake although such underground structures had been considered to have enough seismic resistance. In order to clarify the seismic behavior and performance of large-scale cut-and-cover tunnel subjected to intensive earthquake, the seismic response analysis of such under ground structures in relatively soft soil site was conducted in both longitudinal and transverse direction. The conventionally designed cut-and-cover tunnel can carry intensive earthquake such as Hyogo-ken Nanbu earthquake without significant damage only by enhancing the shear capacity to some members of the tunnel in transverse direction. The conventionally and properly installed structural joint is effective to reduce the seismic demand in longitudinal direction even though against intensive earthquake. According to this study, the enhancement of the seismic performance of cut-and-cover tunnel for intensive earthquake can be performed only by enhancing shear capacity of the tunnel.
