ABSTRACT
Metro station constructed in rock strata is composed of a group of tunnels, mining at the levels both station hall and platform connected via horizontal passages, vertical shaft, and escalator corridors between them. There is sudden change in structural stiffness at a junction of various tunnel cross-sections. The joint of the junction may be sensitive to earthquake excitation. In this experimental investigation, shaking table test of a stratum-station model with geometric similarity ratio of 1:30 was carried out. The model materials of the stratum and the tunnel structure were selected following similitude law. The acceleration responses of the model and the strain of the structure were observed at key locations, when the seismic motion is input in the direction along the cross section of the station. The lateral input of synthetic seismic waves has a significant amplification effect on the ground model in the region of 15~30Hz. The spectrum characteristics of measurements show that the acceleration magnification of the stratum increases in the vertical direction till ground. At the junction between the station tunnel and the vertical passage the amplification effects of acceleration are more obvious than that at another portion. At the spandrel of the lower section of the vertical passage the maximum strain response is the largest.
