MS in Fire Protection Engineering
College of Engineering
Frederick Mowrer and Christopher Pascual
This fire protection and life safety analysis is submitted in partial fulfillment of the requirements for the Master of Science Degree from California Polytechnic State University, San Luis Obispo. The study was performed on the University of Southern California’s Heritage Hall, which includes both a code-determined prescriptive examination and a performance-based analysis. The purpose of this review is to evaluate the Heritage Hall address based on compliance with all applicable codes and standards, as well as the determined occupant tenability criteria. The prescriptive examination of Heritage Hall consisted of the evaluation of all structural fire protection, egress analysis and design, water-based fire suppression, and fire alarm systems. This analysis was primarily performed by utilizing the 2013 edition of California Building Code and the 2013 editions of all applicable NFPA codes and standards. The structural fire protection overview provided an in-depth prescriptive analysis of the conversions made for Heritage Hall during the 2012 renovation project. The latest recapitalization expanded the lower level and added more spaces for student athletes, thus converting those locations to the A-3 occupancy classification. Per CBC Table 601, non-bearing walls and partitions were not required to be fire-rated. The structural update complied with all updated building codes due to a water curtain installed per Section 404.6 of the CBC, which allowed the center museum’s atrium not to be separated by a 1-hour fire barrier. Instead, both glass walls surrounding the atrium were used to create smoke partitions to meet standards. The egress analysis and design was utilized to determine new occupant loads for each floor, remove the B-2 occupancy classification, the creation of a new area of refuge. Per CBC Table 1018.1, corridor walls and ceilings were not required to be fire resistance rated due to the building being fully sprinklered. Only the area of refuge at the lower level was provided with a 1-hour fire rated separation, and existing 1-hour separations, such as the lower level’s exit access corridor, remained intact. Using the Life Safety Code, a building evacuation analysis was performed at Heritage Hall’s lower level. The average evacuation time of all lower level occupants was determined to be 5.43 minutes, with a range of 2.74-8.13 minutes depending on whether occupants used the exit corridor or the stairways. All egress components and occupancy classification were deemed acceptable. The water-based suppression analysis was performed by primarily using NFPA 13 and NFPA 25 codes and standards. A complete analysis of the building’s risers, sprinklers, and system demand calculations provided acceptable criteria for the water-based fire protection system installed. The outside overhang was chosen not to have sprinklers installed due to the large amount of remaining asbestos at the interstitial level near the ceiling. The overhang is made of concrete and directly exposed to the outside. The building’s fire alarm system was installed in 2012, with all new fire detection devices, notification appliances, fire alarm control panel, and a mass notification system. The fire alarm system design was analyzed using NFPA 72, with all spacing and location requirements deemed acceptable for the devices installed. All spot-type smoke and heat detectors are ceiling-mounted in accordance with the open ceiling plan at the lower level, which contains both ceiling and wall-mounted sprinklers.
The performance-based analysis was performed using Fire Dynamics Simulator (FDS), a fire modeling program provided by NIST, and the SFPE Handbook of Fire Protection Engineering. Two unique design fire performance scenarios were established for Heritage Hall: a workstation fire in the first floor atrium and a stacked-chairs fire near the lower level exit corridor that prevents its use. In order to establish a basis for analysis and comparison, various tenability criteria were determined for the building’s occupants. The performance criteria consisted of visibility, toxicity, and tenability requirements for the facility, which were compared with modeling simulations created using FDS. The simulations allowed for the determination of the available safe egress time (ASET). Occupant behavior and characteristics were paired with Thunderhead Engineering’s Pathfinder program to provide a required set egress time (RSET) for each fire scenario. While the lower level corridor fire scenario met all tenability requirements, the atrium’s fire scenario simulation did not provide an acceptable ASET, and therefore did not pass the critical occupant visibility requirements for safe evacuation. Recommendations were provided to establish a legitimate smoke barrier per CBC Section 404.6, or an appropriate door separation for each side entrance to the atrium per CBC Section 715.1.