FIRE SAFETY IN CONSTRUCTION: GETTING IT RIGHT Prof Ali Nadjai: Director of FireSERT BEng(H), MSc, PhD, Ceng, MIStructE, MIFireE, PGCUT ulster.ac.uk Slide 1
INTRODUCTION Canada Sweden Russia FireSERT USA Europe China JAPAN Middle East Qatar Hong Kong North Africa Abu Dhabi Singapore Oman South America South Africa Australia Firesert: Centre of Excellence
Firesert: Centre of Excellence Slide 6 • Provide an internationally competitive research base for fire safety science • Extend/develop the knowledge base for fire safety engineering • Disseminate knowledge to the widest possible audience • To develop and deliver higher technical fire safety education and training programmes • Support industry and Innovation
INTRODUCTION Fires are recognised as one of the major threats of life and property in many countries . The primary goal of fire protection is to preserve life safety. A second goal is to protect property and safeguard the environment. Relatively Young discipline rapidly emerging field Broad and interdisciplinary address complex problems Economic impact of fire in buildings has been estimated at ~1% of GDP – a vast sum now exceeding £10 billion annually
INTRODUCTION Buildings are at the centre of our social and economic activity. Not only do we spend most of our lives in buildings, we also spend most of our money on buildings. The built environment is not only the largest industrial sector in economic terms, it is also the largest in terms of resource flow .
Previous Fire Disasters Building Fires – Compartmentation not well respected Windsor Building Madrid, 12 February 2005
The next day... Insurance payout €300 millio 2 metro lines closed 30,000 people unable to get to work Olympic bid damaged
Taegu Subway Fire Disaster 13 th , FEB, 2003 Fire Arson in Propagation the train Taegu St. Chungangro St Chungangro St Train approach Fire propagation over train 8
Previous Fire Disaster 200 200 150 150 100 100 50 50 WOUNDED WOUNDED DEAD DEAD 9
Seoul 10 th February 2008, 610 year old landmark top national treasure 10
A Warehouse without Tunnel Fires - Explosive Sprinklers Spalling of Concrete Matalan, Birmingham 2 March 2006 loss in business turnover Job losses problems with clients and customer if supply cannot be fulfilled due to fire damage. Channel Tunnel (UK-France, 2008)
Previous Fire Disaster Shanghai high rise residential building, 2010 53 persons died and over 50 injured
Previous Fire Disaster The rate of fires resulting in extensive fire spread involving combustible exterior wall systems is gradually increasing due to the of energy efficient but combustible materials and the consequences of such fires are very large especially for those smart and green high-tech buildings. Shanghai Fire (left) Saif Belhasa building fire, Tecom 2012 (left) & and CCTV Tower, Beijing fire (right). Tamweel Tower fire 2012 (right).
Previous Fire of Disaster what is clear is that there is a need to better understand how façade systems behave in situ , during fires and how the combination of decoration and insulation materials,
Legal liabilities Regulatory Reform (Fire Safety) Order • Responsible person • Fire Risk Assessment of ‘ general fire precautions ’ • Competent person • Enforced by Fire Authority • Problems: • Qualifications? • Skills? • Competency Evaluation?
Research is required to improve Buildings fire safety • Lessons from real fires in real buildings • Full (or large) scale fire tests • Well instrumented and designed small scale fire tests • Materials investigation • Use of smart technology • Robustness of building regulations • More robust and safer designs • Validate d computer software • Validated design methods • Allows optimum design to be determined taking into account life safety, financial impact and environmental issues
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Challenge Fire safety Economic impact of fire in buildings has been estimated at ~1% of GDP – a vast sum now exceeding £10 billion annually
Mechanism of working • EUROPEAN FUNDING Government • EPSRC FUNDING • Fire Research University/ • Fire testing Industry • Fire Guidance and Institute design • Software development • Commerce & Marketing • Training (CPD) • Research Development • Design Rules
Role of the University of Ulster to FireSERT • Supporting the Next Generation Leaders for Fire Safety and Clean Regeneration Energy Application Technology Developing Qualified Human Resources “Developing high level research oriented universities” Select & focus Producing next generation scholars Continuous support for master course, Specialization in Future technologies PhD, and advanced-level researchers Improvement and assistance Top class experts Improvement and assistance of Industry-academic collaboration and education program international cooperation
How Fire spread in Long Corridor Enclosure and Facades The enclosure is made of fireboard (4 cm thickness). Facade 155 cm 300 cm 50 cm Propane burner 50 cm - Side view - - Front view - 4 Opening dimensions (Width × Height) : 0.10 × 0.25 m 2 , 0.10 × 0.25 m 2 , 0.10 × 0.25 m 2 , 0.10 × 0.25 m 2
Flame moving horizontally from the back (location of the burner) towards the opening then ejected (i.e. external burning). HRR profile Temperature profiles 40 1000 Steady-state Theoretical HRR Ventilation-controlled stage Actual HRR Fire Growth 1/2 (Maximum HRR) HRR = 1500 A0 H0 1/2 1500 A 0 H 0 Ejected flame Flame comes out 30 750 Temperature (C) Steady State HRR (kW) 20 500 Ventilation-controlled Decay Box F Box E 250 10 Box D Growth (Fuel-controlled) Box C Box B Box A 0 0 0 10 20 30 40 50 0 10 20 30 40 Time (min) Time (min)
Temperature Profiles EXP. DATA: No external burning FDS 5.3.0: External burning FDS 4.0.7: External burning
How people Behave in fire and modelling fire evacuation
How real building failed in fires a) Early stages, b) spreading in the northwest side, c) extended to entire floor levels
How to use FEM to Analyse failure mechanisms 26
Actions on structures exposed to fire EN 1991-1-2
Structural Fire Safety Engineering vs. Classification
Actions on structures exposed to fire EN 1991-1-2
Natural Fire Safety Concept 1- Implemented in Eurocode 1 Fire Part 2- Some National Fire Regulations include now alternative requirements based on Natural Fire
List of needed physical parameters
Characteristics of the fire compartment
Characteristic of the Fire for different buildings
Fire load density
Rate of Heat Release Curve Stationary State and Decay Phase
Rate of Heat Release Curve Stationary State and Decay Phase
How Fire Engineers interact with other members Structural Research Knowledge Analysis / Calculations Experiences Structural Fire Specialist Architects Structural Code of practice Engineer Solution Fire Engineer Code of practice
Simplified Fire Models
Fully Engulfed Compartment : Parametric Fire
Case study 1: Localised Fire in Large Compartment
2. State-of-the-art and reason for the project Reason for the project Annex C of EN 1991-1-2: Annex C of EN 1991-1-2: Flame not impacting the Flame impacting the ceiling ceiling Flame axis concrete slab θ H g beam Y L f z D Y = Height of the free zone How to calculate the temperature in a column subjected to the radiation of the fire ? 41
Localised Fire: Annex C of EN 1991-1-2
DESIGN OF COLUMNS SUBJECT TO LOCALISED FIRES The effects of a local fire result in four distinct regions, each of which receives different levels of heat flux. These regions can be split as follows: 1- Outside the fire 2- Inside the fire 3- Inside the fire, in the smoke layer 4- Outside the fire, in the smoke layer It assumes that the shape of the fire on the ground is circular and is intended for localised fires that do not exceed a diameter of 10 m and a heat release rate of 50 MW .
Analytical method and validation Modelling of the flame Step 1: The surface of the fire is transformed into an equivalent discus Step 2: The evolution of Heat Release Rate is calculated according to EN 1991-1-2 Annex E (growing phase, plateau, decaying phase) Step 3: The flame length L f is calculated by application of EN 1991-1-2 Annex C Step 4: The action of the fire is represented by a virtual solid flame, conic or cylindric, defined by D eq and L f Cylinder Cone Q (or model model HRR) constant L f HRR max (fuel or ventilation paraboli controlled) c linear time D eq D eq 46
Analytical method and validation Simplified model Sub-division of the flame into cylinders and rings If the flame does not touch the ceiling If the flame does touch the ceiling (L f < H ceiling or no ceiling) (L f > H ceiling ) 47
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