Date
6-2021
Degree Name
MS in Fire Protection Engineering
College
College of Engineering
Advisor
Frederick Mowrer and Christopher Pascual
Abstract
The purpose of this report is to analyze the Warren J Baker Center for Science and Math on the California Polytechnic State University, San Luis Obispo campus. Baker Science is primarily used for classroom and laboratory instruction of college students, with study spaces, faculty offices, and assembly spaces. There are mechanical, electrical, and storage spaces ancillary to the main building functions. The building comprises six floors that are between 23,000 and 44,000 ft2. The first floor contains classrooms, faculty offices, mechanical/electrical spaces, and an auditorium with fixed seating. An atrium connects floors two through five. There are walkways running down the center of the atrium with openings on both sides. These floors all contain a mix of classrooms, laboratories, faculty offices, study spaces, and supporting mechanical, electrical, and storage rooms.
The prescriptive analysis of the Baker Science building determines if the building construction complies with the applicable codes and standards. These codes and standards cover life safety, fire suppression, fire alarm and detection, and structural requirements. The life safety section analyzes the ability of the building to safely evacuate occupants in a timely manner. This is accomplished with code-specified stair and door widths, exit locations, and exit fire rating requirements. The building is protected throughout with an automatic wet pipe sprinkler system, fed from a fire pump on the first floor. The fire pump is supplied from a city water loop to the north of the building. All sprinklers in the building are quick response K-5.6 sprinklers. The fire suppression system activates the fire alarm system in the event of a fire. The alarm system can also be activated with smoke alarms, heat alarms, and manual pull stations. The generation of any part of the fire alarm system in the atrium will activate the passive smoke control system. This system opens roof vents that allow smoke to escape, and also opens doors at the bottom of the atrium to provide makeup air. Doors to the wings of the building are released and closed to reduce the travel of smoke to the east and west wings. The structural fire protection codes provide occupancy separation requirements, and limit building height and area based on construction type.
The performance based analysis seeks to determine how well the building systems can handle a real-life fire scenario, with a focus on building occupants being able to safely evacuate the building in the event of a fire. The ability to safely exit the building is based upon the requirement for tenability to be maintained in the egress route for the entire time it takes for evacuation to be completed. The performance analysis in this report centers around two design fires: one in the atrium, and one in the lobby outside the assembly space. The design fires represent scenarios that would challenge the fire protection capabilities of the building, while still having a probability of occurring. Small fires or fires in unoccupied spaces were not analyzed since they would be unlikely to test the limits of the building’s fire protection systems. The design fire in the atrium exposed occupants to smoke and combustion products, and activated the atrium smoke control system. The smoke venting was inadequate to remove the smoke created by this design fire, resulting in smoke accumulation that limited the visibility of occupants egressing on the sixth floor. The available safe egress time is 3.23 min after ignition, based on the minimum visibility of 4 m being lost on the sixth floor, while that floor has a required safe egress time of 3.96 min. The design fire in the lobby outside the auditorium also exposed occupants to smoke, limiting visibility. The available safe egress time in the lobby is 2.00 min, at which point the 13 m visibility limit is no longer maintained. The required safe egress time is 8.64 min from the time of ignition, significantly longer than the time available to occupants.
Prescriptive analysis of the Baker Science building determined that the building was adequately built to the relevant life safety and fire codes. The performance based analysis discovered some shortcomings in the building design. These faults were primarily centered around tenability time for evacuating occupants in the building. On the sixth floor in the atrium, occupants experienced reduced visibility that could impede their ability to safely find the exits and safely escape. The cause of the reduced visibility was the buildup of smoke from the fire, which in turn was caused by inadequate smoke removal by the smoke control system. As a passive system without fans, the smoke can only be removed at a limited rate. One solution to this would be to install additional passive smoke vents. A better solution would be to install powered smoke vents with a rating capable of evacuating adequate smoke from a challenging design fire. Inadequate visibility was also the conclusion of the second design fire. The tall ceiling outside the auditorium filled with smoke, limiting the visibility of evacuating occupants. Installing smoke control capability in the lobby could remedy this deficiency. An easier solution would be to install doors in the auditorium that do not egress into the lobby. This would allow auditorium occupants to avoid the smoke entirely, while reducing the congestion in the lobby for people evacuating from other parts of the first floor. The Baker Science building serves as an example of properly executed code implementation, with failings that can be exposed with demanding design fires.
https://digitalcommons.calpoly.edu/fpe_rpt/137
Final Presentation