Shaking table test on shield building considering soil-structure interaction

Since the site selection of nuclear power plants has been extended to non-rock sites, soil-structure interaction (SSI) must be considered in the design of the nuclear power plant. In this paper, the shield building of CAP1400 was selected as the research object to make a simplified model, and two shaking table tests were carried out to study the influence of SSI. The results show that SSI will lead to a decrease in the natural frequency. In the time domain, considering SSI can reduce the peak seismic responses of structure. Under the action of 0.30 g PGA ground motion, the relative difference of peak acceleration is about 50%–70 %, and that of peak strain is about 60%–80 %. In the frequency domain, considering SSI can cause the acceleration response spectrum to move to the long period. If SSI is not considered, the design results will be conservative in the frequency band of the main frequency of the structure, while that will be small in the long period band. Moreover, when the floor acceleration response spectrum is used to design the equipment and pipelines inside the shield building, the wrong calculation results may be obtained.