EMERGENCY EVACUATION TIME ESTIMATION FOR FIRE SAFETY DESIGN OF ASSEMBLY BUILDING

Abstract

The objective of this work is to demonstrate the feasibility of a performance based design for providing adequate life safety level for the occupants in a dining hall (assembly building). For performance based design available safe egress time (ASET) and required safe egress time (RSET) are estimated and their values are compared. Available safe egress time is estimated using 'Consolidated Model of Fire Growth and Smoke Transport' (CFAST) which is a popular zone model used for modelling the enclosure fire. For better result multi-cell approach is used here for ASET estimation where the entire compartment is divided into number of sub compartments and walls between the sub compartments are replaced by equal size vents. Effect of compartment division and location of the fire source on ASET estimation are also observed by dividing the dining hall space into 20, 21, 25, 29, 30 sub compartments. For estimation of required safe egress time, travel time is estimated using evacuation model EVACNET4. EVACNET4which is advance version of EVACNET+, gives optimum time to evacuate the building. Travel time estimated by EVACNET4 does not include behavioural aspect of the occupants which is estimated in terms of pre-movement time. Pre-movement time is estimated by Sime's method which is included in Draft British Standard Fire Engineering Code 1994. In order to provide active fire protection measures effect of installation of fans and sprinklers inside the hall are also studied.