Fire and Life Safety Evaluation of Christopher Cohan Center

Author

Mishuk Datta, California Polytechnic State University, San Luis ObispoFollow

Date

3-2017

Degree Name

MS in Fire Protection Engineering

College

College of Engineering

Advisor

Frederick Mowrer and Christopher Pascual

Abstract

A prescriptive and performance-based fire and life safety evaluation for Christopher Cohan Center is performed. The results and findings of the evaluations are conveyed in this report. Christopher Cohan Center was built in accordance with California Building Code (1992 Edition) and California Fire Code (1992 Edition). The current version (2015) of International Building Code is consulted for prescriptive evaluation. The protection requirements set forth in IBC are intended to limit the threat from stage fires to an audience, to reduce the likelihood of a large fire in the stage area and to reduce the possibility of irrational mass response. These objectives have been identified as primary parameters to evaluate the fire and life safety systems of the building. Christopher Cohan Center was constructed of Type IB construction with a sprinkler system throughout the building. Legitimate stage is completely separated from seating by a proscenium wall of 2-hour fire-rated construction with the main proscenium opening protected by an automatic closing fire protection curtain in accordance with IBC 410.3.5. A wet pipe, hydraulically calculated automatic sprinkler system is provided throughout the building. A hydraulic calculation was performed in accordance with NFPA 13, which shows that, the city water supply is not adequate for the sprinkler system and hose stream demands. The main exit of the Sydney Harman Hall accommodates a total occupant load of 1,440, which is more than the total occupant load of the hall, 1,289. This arrangement complies with IBC section 1029.2. In addition to having access to a main exit, Christopher Cohan Center is provided with additional exits from the balcony level, gallery level, orchestra stage, and entry lobby. These exits provide an egress capacity of 5,280 persons from orchestra stage and entry lobby levels and 960 persons from balcony and gallery levels, which are more than the total occupant loads served by an individual level. In the event of an alarm, Christopher Cohan Center Ushers are required to assist in the evacuation process. A fast-growing fire is modeled in FDS, which shows activation of gravity vents between 349 and 436 seconds, fire protection curtain activation at 440 s, and first sprinkler activation at 498 second after ignition. The tenability criterion is established to be the smoke layer descend within 2 m. above any means of egress. This criterion is predicted to occur at 210 s. in the zone model. FDS model does not predict smoke layer to descend within 2 m. above any means of egress, within the simulation time (570 s.). FDS model also shows that, the proscenium structure can contain the smoke until 300 s. FDS predicts the smoke detector will activate at 274 second. The notification of the fire event is expected to be triggered by the rapid descend of smoke layer, possibly shading or obscuring lighting effects dropped from the grid-iron, or by occupants, present in the fly gallery, sensing the presence of smoke, can initiate the notification of the fire event by activating manual fire alarm, long before the automatic detection devices detect the fire cues and initiate activation of the fire alarm. Based on the evaluation of the building and stage construction, the stage construction and fire separation play key-role in limiting the threat from a stage-fire to the audience due to its containment of smoke long enough for the audience to evacuate the hall. It can also be confirmed that the installed systems will not perform to meet the performance criteria. The building would be relying on human actions to detect fire, to annunciate, and to suppress the fire. To reduce the likelihood of a large fire in the stage area human intervention would be a crucial factor. Also, the collective effort of the egress system and human-assistance play a crucial role in evacuation process, which contributes to ensure minimal exposure to the fire environment. Due to effective evacuation and egress system, the possibility of irrational mass response is expected to be minimal. Recommendations include the incorporation of a fire pump based on the hydraulic demand for the most challenging design area. Proper inspection, testing and maintenance of the suppression systems is required, in accordance with specified standards. Additional requirements specified in the fire safety management plan must be included in the ‘Emergency Management Plan’ for Christopher Cohan Center. This includes engaging dedicated fire watch personnel and crowd managers during events, and incorporating specified employee training and response procedures along with all the emergency management procedures that are currently in place.