Phoenics Conference 2004 Phoenics in Safety Analysis of Offshore and Underground Constructions Dr Terje Toften, Dr Bård Venås

Background - Objective Phoenics in Safety Analysis > 15 years. Most important application area today. Review using versions from 1.4 to 3.5 Purpose, Implementation, Advantage Confined to Fire Safety Analysis

Offshore constructions Norway, North sea, Ekofisk, Troll, concrete platform, 472m high. Piper Alpha UK, fire 1988, 167 lives. Sleipner A, sunk 1991, seismic event, 3.0 on Richter scale, Nothing but a pile of debris, of $700 mill Wind tunnel -> CFD, 15 years ago

Underground constructions Mountains & Fjords - thousands of tunnels Norwegian railway tunnels has taken no lives, yet. Common safety elements People, size, fire load, technical outfit, access. King’s Cross underground St. London 1987, took 31 lives. Common safety regulations in EU

Safety Analysis Murphy’s law: If anything can go wrong, it will. Risk = Probability x Consequence Safety analysis is part studies in overall risk analysis of Health, Environment and Safety

Offshore Fire Safety

Probability – Fuel Gas leakage Oil spill Dispersion Scenarios Barriers Diffuse and Jet H 2 gas leakage 4% LEL after 1 and 30 seconds

Probability – Oxygen (Air) Natural wind Ventilation 12 ach, 95% of the time Design of claddings Ventilation Efficiency Hazard areas, LEL-HEL Gas detection systems Ekofisk 2/4J, 1994

Fire Analysis Fire scenarios Dispersion Heat/Smoke Evacuation conditions Escape route placing Critical areas, life boats Thermal load Protection efficiency Oil spill fire 400MW onboard Grane

Consequence Analysis Personal, death, injuries Property, insurance loss Valuables, irreplaceable, cultural Environment, industry, community Incapacity and lethal dose of smoke Heat, T<60’C, Radiation Smoke, poisoning Oxygen, suffocation Visibility, 10m escape routes

Loss Prevention Technical, Active & Passive Arrangements Organisational, Inspection, testing, education Providing smokeless access with walls

Underground Fire Safety Tunnel length: 2,3km Station LxWxH: 110x20x5m Pressure shafts Trains m carriages 3 escape routes, 7min Nydalen St. in Oslo - Smoke Ventilation

Phoenics Model Entrance, escalator, east staircase Ca cells, 30s time step Sensitivity testing Platform area and ducts – looking west

Fire Simulations FIRE SCENARIO Fire detected, train stopped Shafts closed, ventilation started Phoenics simulations start Fire 20MW/0.9kg/s in 14min Computed Temperatures and Velocities VARIABLES Ventilation system design Ventilation capacity, minimum Ceiling / Screen design Evacuation conditions

Results and Analysis ANIMATION Surface plot Smoke Concentration Loss of visibility (5m) Exhaust 300,000m 3 /h, 4 ducts, new ceiling

Underground Tunnels Special Considerations Tunnel construction, gradient Fire dimension and development Limited/Long evacuation Natural wind and buoyancy Tunnel fan efficiency and fragility Simulation of tunnel fan response time Evacuation during a Fire in a BM69 train

Fire Simulation Surface, 3m visibility Ventilation 3m/s Fire 200MW Tid = 16 min Tid = 2 min

Verification full scale Lindeberg train station 110m platform m 3 /h 10MW fire Linderberg St. -Full scale test Verification Full scale test Measurements Visualisation

Tests and Measurements National Theatre St. Smoke visualisation Natural wind and buoyancy Tunnel measurements

Concluding Remarks The application of Phoenics in Safety Analysis is practically unlimited. The reliability of its performance has been confirmed by verifications. Phoenics is a natural safety analysis tool for construction engineers today.