ABSTRACT
A series of 1g shaking table tests were performed to investigate the response of Tabriz subway tunnel, a circle-type tunnels embedded in dry sand, under sinusoidal excitation. Effects of various parameters, including peak ground acceleration and frequency content of input motion on the behavior of tunnel was investigated. Tests were performed in two peak ground accelerations, 0.35g and 0.50g, and different frequencies. The experimental data are presented in terms of dynamic lining forces. Results show that the tunnel moves from a static equilibrium to a dynamic equilibrium state as soon as the earthquake starts. In addition, measurement of shaking table experiments shows that by increasing the frequency of loading, induced maximum strain almost remains constant or decreases little for A = 0.35g but decreases sharply for A = 0.50g.
