What is the probability of fire to spread in a car park? PhD candidate: Zahir Tohir Supervisors: Michael Spearpoint Charles Fleischmann

Place: Westfield Westcity Henderson Time: Around AM Fire fighters attended the fire and carried out full evacuation of the mall Auckland van fire – 27 Feb 2015

Van fire – 27 Feb 2015

Should there be a vehicle parked next to the van, will the fire be able to spread? Question?

Should there be a vehicle parked a space away to the van, will the fire be able to spread? Question?

To quantitatively assess the probability of fire spread from a burning vehicle to another vehicle within vicinity using probabilistic analysis. Objective

Research overview Risk-based research Car park scenarios Fire spread between vehicles Vehicle characteristics Vehicle design fire Application

What is the typical parking space dimension in a car park? Parking space dimension Width Length

SourceParking space dimensionsReference Width (m)Length (m) Parking structures: planning, design, construction, maintenance and repair 2.2 – 2.7N/AChrest et al. (2000) Car park designers’ handbook2.3 – Hill (2005) County of San Diego Parking Design Manual Department of Planning and Land Use (2013) Asphalt paving design guide2.7 – Asphalt Paving Association of Iowa (1990) Information bulletin / Public-zoning code: Parking design 2.3 – – 5.4 Department of Building and Safety (2002) USAF Landscape Design Guide US Air Force (1998) Parking Design Standards2.5 – 3.2N/AFife Council (2006) Parking Standards Design and Good Practice Supplementary Planning Document 2.5 – – 5.5 Rochford District Council (2010) Parking Structures: Recommended Practice for Design and Construction 2.3 – 2.7N/APrecast Concrete Institute (1997) Parking space dimension

Probability of fire spread scenarios Scenario 1 – Scenario 2 – a – vehicle width, b – distance between vehicle to the border of the parking space, c – parking width EFFECTIVE DISTANCE = a + b (+ c)

Approach Use probabilistic simulation approach Statistical distributions of: – Vehicle fleet distribution – Design fire of a single vehicle distribution

Vehicle classification by curb weight ClassificationCurb weight Passenger car: Mini1500 – 1999 lbs (680 – 906 kg) Passenger car: Light2000 – 2499 lbs (907 – 1134 kg) Passenger car: Compact2500 – 2999 lbs (1135 – 1360 kg) Passenger car: Medium3000 – 3499 lbs (1361 – 1587 kg) Passenger car: Heavy≥ 3500 lbs ( ≥ 1588 kg) Van / MPVNot defined SUVNot defined Based on American National Standards Classification

Statistical distribution – Vehicle fleet International data NZ data

Statistical distribution – Design fire of a single vehicle Peak heat release rate (kW) Fire growth coefficient (kW/min²) Fire decay coefficient (min -1 ) Distribution shapeWeibullGammaWeibull Distribution parametersαβαβαβ Class Mini Light Compact Medium Heavy3.11*8723*1.51*1.82*1.86*0.11*

Statistical distribution - Example

Ignition prediction characteristics – flame radiation model = heat flux received by the target = heat output from the burning item λ r = radiative fraction R = radial distance from the center of the burning item to the nearest point of secondary item 0.3 – radiative fraction selected Secondary item Q R

Ignition prediction characteristics – ignition criterion FTP = and heat flux = 3.1 kW/m 2

Estimation of probability Scenario 1 Scenario 2 Where y is the probability of fire spread and x is the effective distance

Sensitivity analysis Varying vehicle fleet distribution datasets New Zealand data International data

Conclusion & Recommendations