Design of Evacuation System for High-Rise Building Danqing Yu

1. Design of Evacuation System for High-Rise Building Danqing Yu

2. Overview • 30-years policy of US codes against use of elevators in fires ~ Attitudinal impediment • Focus of current design: number, width and position of stairs ~ Is it adequate? • Current use of elevator – Provide emergency use for firefighters and the disabilities • Move large number of people from significant height ~ Call for safe and reliable elevator egress system • Future trend ~ design elevators with emergency mode ( withstand heat, smoke, water, power-cut)

3. Evacuation Plan for High-Rise Building • Normal high-rise building • Evacuation sequence: emergency floor – upper floors – lower floors • Whether or not the elevators attend to disabled population first before they serve others • Trained personnel to lead evacuation and good interface design ( switching driving mode for different emergencies) • Mega high-rise building • Elevators and refuge place are zoned vertically by sections • Occupants are regularly trained for evacuation • Express emergency shaft transit from refuge place to ground lobby in a non-stop fashion

4. Buildings Types Need Emergency Elevators • Residential Building • Buildings with more than 100 persons per floor and with more than 50 floors • Buildings with more than 200 persons per floor and with more than 20 floors • Office Building • Buildings with more than 50 floors and more than 50 persons per floor • For 15-20 floor building, population per floor exceeds 100

5. Parameters for Evacuation System • Parameters of Building Evacuation Traffic Flow • Building population • No. of floors: f (1 f  F) • Average passenger walking speed: (0.5~0.75m/s) • Passenger density during emergency (1 person/0.46m2) • Configuration for Evacuation System • Proportion of population evacuated by stairs and elevators • Width of evacuation doors (> 0.8m) • Width and travel distance of stairs • Positions of stairs and lobbies • Size of the lobbies • Emergency elevator configuration (number, safety mode, driving speed, group control logic )

6. Objective: Minimize total passenger evacuation time ~ Time between the beginning of evacuation and the time when the last passenger departs. Min Te, with Te= max (Tstairegress , Televatoregress) • Evacuation by stairs • Evacuation by elevators ~ Assume elevators are loaded by passengers from one floor Corresponding to different highest reversal floor Statistical Method

7. Constraints associated with building traffic flow • Space limitation • Budget consideration • Service quality requirement Normal mode Emergency mode • Objective for configuring traffic system • Minimize the weighted sum of average waiting time (or total service time) during normal mode and the evacuation time during emergency mode

8. Safety regulation • Emergency mode for elevators Water tolerance parts, Emergency power if main power fails Enclosed lobby on each floor of the building, elevator should be installed in smoke-proof shaft 1 hour fire resistance and pressurized against smoke infiltration. Real time monitoring of elevator system status and any conditions that may threaten its safe operation. • Max No. of elevators and stairs • The number of floors in each elevator zone  15 ~ 16 floors • Layout of elevators and stairs Typical building: 3000 m2 of floor space, 500 m2 core area (including elevator, 2 stairs: 1.2 m each) Stairs are located diagonally across the core area from each other.