Fire safety in heritage structures: A case study on heritage temple with performance-based design fire approach

Abstract

Abstract Heritage structures are continuously subject to fire accidents due to the presence of combustible materials that result in the loss of heritage as well as the fatality of occupants. The probability of fatalities increases when the limit of the number of occupants is violated. Fire accidents in Indian heritage temples witnessed a huge number of deaths due to incapacitation and stampedes. This study aims to evaluate fire hazards (thermal, visibility, and toxic hazards) using a performance-based design fire approach for an Indian heritage temple. A heritage model temple was created in Fire Dynamics Simulator (FDS) with dimensions of 19.25 m × 19.25 m × 9.75 m. A design fire of 5 MW was specified for three different fire growth rates i.e., medium (0.012 kW/s2), fast (0.047 kW/s2), and ultrafast (0.19 kW/s2). Thermal, visibility, and toxic hazards expressed in terms of temperature, visibility, and concentration of CO2 and CO reached the tenable limit in 170, 160, 383, and 176 s respectively. Thus Available Safe Egress Time (ASET) for occupants was only 160 s. The effect of soot yield and ventilation conditions on fire hazards was also analyzed. Required Safe Egress Time (RSET) estimated with an egress model for an occupant load factor of 1.4 m2/ person as per the National Building Code of India 2016 was found to be 109 s. The safety margin between ASET and RSET was increased significantly with the help of two smoke extractors. The results obtained from this study will provide valuable insights into fire safety measures in similar heritage structures.