ABSTRACT
This paper describes the seismic hazard mitigation program implemented by Chevron USA Products Company at their two major California refineries, each having a production capacity of over 250,000 barrels of oil daily. A brief historical background of the program inception is presented. Issues dealing with proactive risk management, educating decision makers about seismic risk, liability of study results, and funding are addressed. Understanding the political and economic impacts of publishing a report outlining potential seismic deficiencies at a major industrial facility is critical to the success of implementing a seismic hazard mitigation program. The major technical focus of the paper is to describe the walkthrough process of identifying “critical structures” for further analytical review and to present some of the innovative approaches that were taken to remove conservatism from the resulting analytical assessment. The methodology used to establish retrofit priorities is also presented. This method utilized the calculated earthquake return period corresponding to each structure’s ultimate capacity, together with consideration of its consequence of failure. A risk analysis matrix relating these concepts was prepared resulting in a powerful tool for the owner to consider when funding retrofits.
