Shaking Table Test on the Seismic Response of a Frame-Type Subway Station in Composite Soil

Abstract

With the development of urbanization, numerous underground structures were constructed in composite soil. It is common that the aseismic capacity of the underground structure is influenced by the soil. Hence, during the seismic design, the underground structure located at the composite soil should be noticed. In this study, the seismic response of a frame-type subway station located in composite soil was explored by shaking table tests. The acceleration response, the strain distribution, and the earth-pressure distribution of the model system under the motion of the Kobe wave and the Chongqing artificial wave were obtained and interpreted. The test results demonstrated that the peak acceleration response of the model soil and the model structure increases with the input acceleration and the distance to the shaking table. The acceleration response of the model soil is influenced by the location of the model structure, and the model soil can determine the seismic response of the model structure. The strong strain response of the model structure occurred when the peak accelerations of both input waves were greater than 0.4g. Under the action of major earthquakes (e.g., PGA = 0.4g, 0.8g, and 1.0g), the strain at the top of the upper intermediate column and the bottom of the lower intermediate column is significantly greater than that of other components. It is suggested that the ductility of the intermediate columns ought to focus on the seismic design of the frame-type station located in composite soil. The maximum earth-pressure occurs in the middle of the external side wall. The earth-pressure pattern demonstrates a U-type distribution in the X-direction, and the distribution characteristics are more significant as the input peak acceleration increases.