抄録
There are some cases in which towers and piping with insulation have become externally corroded after long usage. The FFS (Fitness for Service) code based on the p-M method proposed by Konosu et al. can be used to assess the structural integrity of towers and piping with local thin areas simultaneously subjected to internal pressure and external bending moment.
However, in order to assess structural integrity by the p-M method, it is necessary to evaluate the bending moment due to earthquake, etc. , at the location with the local thin area concerned.
There is an earthquake resistant design code published by the High Pressure Gas Safety Institute of Japan (KHK) in which details relating to seismic loads are given.
In this paper, the seismic moment for various towers is calculated as per (1) static coefficient method, (2) modified static coefficient method and (3) modal analysis method etc. By comparing these results, the simplified equation based on the static coefficient method and the modified static coefficient method is proposed.
