Accidental blast events at petrochemical facilities such as BP Texas City have shown that the occupied buildings near the process areas can be vulnerable to blast and collapse even under low blast overpressures. Additionally, existing permanent and portable buildings may exhibit insufficient capacity to resist blast loading during facility siting studies per API RP 752 and 753. Although it is not possible to completely eliminate risk from blast loading, it is possible to minimize the individual risk, which is a probability an occupant will experience fatality due to an explosion event, by applying retrofit and upgrade strategies to increase the blast-resisting capacity of an occupied building and meet the safety performance criteria.
There are several ways to decrease individual risk due to explosion with respect to occupants in a building:
- Moving the building from a high blast region near the process area to a lower blast region, and design a new building;
- Retrofitting existing occupied building;
- Replacing existing occupied building with a blast resistant modular building; and
- Replace the existing occupied building with a new blast resistant building.
The first and forth options can be inefficient from construction cost and time perspective. Additionally, the first option may require purchasing an additional land and obtaining permit. The second and third options are significantly cost and time efficient, and causes less interruptions for the operations. However, these options require analysis and engineering judgment from a highly skilled and experienced engineer. In this paper, case study will be presented where a variety of retrofit and upgrade options will be discussed from perspectives such as design, constructability, cost and individual risk.