# Seismic Response of a Large LNG Storage Tank Based on a Shaking Table Test
## 4 Comparative Analysis of Results
### Isolated Storage Tank  
Through the Newmark-\(\beta\) method, the parameter matrix of the structure is brought into the motion control equation and the theoretical solution of the isolated storage tank model is finally obtained, with four different seismic waves selected, El Centro wave, X one-direction loading Wolong wave with peak acceleration of 0.25 g, XZ two-direction loading Taft wave with peak acceleration of 0.5 g and XZ two-direction loading artificial wave with peak acceleration of 0.25 g, respectively. Figures 13-16 show seismic isolation under different working conditions and compare the experimental data of the storage tank with the theoretical solution (Newmark-\(\beta\) in the figure is the theoretical solution and the test data is the experimental data). Figure 10: Comparison of shaking table test data and theoretical solution under the Taft wave: (**a**) dome acceleration time history and spectrum comparison; (**b**) cushion cap acceleration time history and spectrum comparison; (**c**) pile foundation acceleration time history and spectrum comparison. Figure 11: Comparison of shaking table test data and theoretical solution under the Wolong wave: (**a**) dome acceleration time history and spectrum comparison; (**b**) cushion cap acceleration time history and spectrum comparison; (**c**) pile foundation acceleration time history and spectrum comparison. Figure 12: Cont. Figure 12: Comparison of shaking table test data and theoretical solution under the artificial wave: (**a**) dome acceleration time history and spectrum comparison; (**b**) cushion cap acceleration time history and spectrum comparison; (**c**) pile foundation acceleration time history and spectrum comparison. Figure 13: Comparison of shaking table test data and theoretical solutions under the El—Centro wave: (**a**) dome acceleration time history and spectrum comparison; (**b**) cushion cap acceleration time history and spectrum comparison; (**c**) pile foundation acceleration time history and spectrum comparison. By comparing the seismic acceleration response time history obtained from the shaking table test and theoretical analysis of the isolated storage tank, the following conclusions can be drawn:  
(1) Compared with the pile foundation and the cap, the acceleration response of the dome is the most severe, and the acceleration time history of the pile foundation, the cap and the dome is only different in amplitude, but the waveform does not change significantly. This phenomenon is the same as the seismic response law of non-isolated storage tanks. (2) It can be seen from the spectrogram that under the excitation of the El Centro wave, Taft wave and artificial wave, the isolated storage tank dome, pile foundation and bearing platform all produce the maximum acceleration response when the frequency is 6 Hz. Under the excitation of the Wolong wave, the storage tank produces the maximum acceleration response at 13 Hz. Compared with the non-isolated storage tank, the frequency of the maximum acceleration response of the seismically isolated storage tank is lower, indicating that the isolation bearing can effectively increase the characteristic period of the storage tank and reduce the resonance effect of the seismic wave, thereby eliminating the energy of the seismic wave and finally ensuring the isolation. Safe operation of seismic storage tanks under the action of earthquakes. Figure 14: Comparison of shaking table test data and theoretical solutions under the Taft wave: (**a**) dome acceleration time history and spectrum comparison; (**b**) cushion cap acceleration time history and spectrum comparison; (**c**) pile foundation acceleration time history and spectrum comparison.