2021 Volume 77 Issue 2 Pages I_543-I_550
It is desirable for spherical gas holders, which require a high level of safety, to be able to retain their functions during aftershocks even when the foundation is subjected to unequal settlement due to a large-scale earthquake. For this purpose, it is necessary to develop a simple method to evaluate the seismic resistance of inclined gas holders under the assumption of maximum aftershocks, which will contribute to the decision on whether or not to use the holders after a large-scale earthquake. The analysis to evaluate each element of the holder must take into account the material and geometrical nonlinear response mechanism of the supporting structure and nonlinear dampers, and it is not realistic to conduct detailed evaluation by 3D analysis in a short period of time after an earthquake. Therefore, in this paper, the simple evaluation method using a single mass-spring analysis that reflects the nonlinear spring characteristics from the pushover analysis is proposed. This method shows good agreement with the dynamic response of a 3D framework model of an actual gas holder until the maximum response value, and after that, the response value is calculated on the safe side, which means that the aftershock seismic resistance of the holder can be evaluated.
