In general tanks are susceptible to damage during earthquakes. When results of a tank inspection show the existing condition of the tank can not satisfy the current seismic codes, an evaluation shall be made to determine its suitability for continued use. This paper develops a seismic mitigation plan, which combines information from seismology and earthquake engineering to petrochemical science and economy. The plan as a performance-based seismic mitigation plan makes it possible to relate operation levels of the tank, failure modes, fragilities, ground motions, earthquake scenarios, retrofitting design, replacement or change of service by considering safety, practicability and cost-benefit analysis in a single framework.
