Study of the Near-Fault Effect on the Sloshing Mode of Storage Liquid in Tanks

Study of the Near-Fault Effect on the Sloshing Mode of Storage Liquid in Tanks

The long period velocity pulse is recognized as one of the characteristics of near-fault ground motions, and hence the response of vibration modes with lower frequencies will be amplified due to the effects of resonance. In general, the sloshing frequency of storage liquid in tanks is low and the period is similar to the pulse period of near-fault ground motions. Compared to far-field ground motions, the induced slosh height will be amplified significantly by the near-fault ground motions due to the resonant excitation. Therefore, it is worth considering the near-fault effect on the sloshing mode of liquid stored in tanks. This study aims to describe the test setup, the selection and processing of input motions including the original near-fault ground motions, the extracted velocity pulse or extracted band-pass signals for resonance analysis, and the impulse motion for free vibration. In addition, the experimental results are compared with the code-specified values as determined by the industrial standards and guidelines for general seismic conditions. It is expected that based on the test results, a more proper prediction equation can be proposed for the seismic design and evaluation of the spent fuel pool in nuclear power plants.