Design criteria for public cyclone shelters Dr Peter Mullins Mullins Consulting Brisbane TC Yasi 2nd Feb 2011
Evacuation Storm tide inundation Harvey Bay Storm Tide Model Vulnerable houses Tully TC Yasi Feb 2011 Yeppoon TC Marcia Feb 2015
Shelter options Leave Shelter in modern home Shelter in public buildings Innisfail TC Yasi Feb 2011 Cairns TC Yasi 2011
Existing public buildings Innisfail SHS TC Larry 2006 Tully Senior Citizen Hall TC Yasi Feb 2011 Innisfail SHS TC Larry 2006
Purpose built cyclone shelters Redlynch SC Proserpine SS Tully SS Innisfail SHS
Design criteria Siting Design actions Building elements Access, occupancy and egress Fire safety Health and amenity Ancillary provisions Design and construction assurance
Siting Storm tide hazard (1:10,000 storm tide) River and creek flood (Q500) Landslip hazard (risk to life VL, to property L or VL) Proximal hazards (buildings, trees, hazardous materials) Vehicle and pedestrian corridors (accessible to community) Limited use helicopter landing site (eg. sports oval)
Storm tide hazard Above the evacuation zone for the 1 in 10,000 storm tide Uncertainty in cyclone track location and time increases evacuation zone. Greater length of coast is evacuated due to uncertainty of landfall. Forecast storm tide is based upon the highest tide of the day
Design actions Wind speed Wind borne debris Permanent and imposed Earthquake Wave and flood flow (applicable to lower levels of a shelter on a sloping site with access to ground beyond the evacuation zone and flood inundation)
Wind speed Annual probability of exceedance of 1 in 10,000. Probability at a single location. Probability increases with number of locations. Australian Standards Wind Code (AS1170.2) Region C: V 10,000 = 306 km/hr Region D: V 10,000 = 392 km/hr
Wind borne debris 100x50 timber member of 4kg mass impacting at 0.4V 10,000 horizontal trajectory (Region C 122km/hr; Region D 157km/hr) 0.1V 10,000 vertical trajectory (Region C 31km/hr; Region D 39km/hr) Load B: 8mm diameter steel balls impacting at 0.4V 10,000 horizontal trajectory (Region C 122km/hr; Region D 157km/hr) 0.3V 10,000 vertical trajectory (Region C 92km/hr; Region D 118km/hr) Innisfail SHS TC Larry 2006 Kurrimine Beach TC Larry 2006
Wind borne debris Tests solid core door 50mm plywood door steel clad door 4kg impacting at 122 km/hr
Wind borne debris Tests
Wind borne debris Tests
Building elements Roof External walls & doors Debris screens, windows and louvers Internal ceilings, partitions and doors Site drainage Element certification and testing
Roof Design to resist wind and wind borne debris Roof slope < 15 degrees to avoid horizontal trajectory debris missile. Screw fixed. Design building shape to reduce wind pressures. Drain roof water Q500
Debris screens Windows and louvers
Internal ceilings partitions and doors Suspended ceiling hanger rods do not resist positive internal pressure. X Construct ceiling and internal partitions to resist internal wind pressures. Install ventilation grills in doors and hatches in ceilings to reduce differential internal pressures.
Access, occupancy and egress Location and building signage Access and safe movement People with disabilities Occupancy Occupancy duration Egress- Alternative building solution
Location and building signage
Occupancy Design capacity based upon: 1 person per 1.2 m 2 of shelter floor area 50 people per toilet Design occupancy period: Total occupancy period 36 hrs A lockdown period of 18 hrs
Shelter area
Egress Alternative Building Solution required for each shelter
Fire safety Fire resistance and stability Compartmentation and separation Smoke detection and alarm system Fire hose reels Automatic fire suppression system Fire extinguishers
Compartmentation and separation Main electrical switchboard, emergency power switchboard, diesel generator, emergency lighting batteries and uninterrupted power supply to be smoke and fire separated from the shelter space with fire resistance levels (FRL) of 120/120/120.
Fire hose reels and Fire extinguishers Fire hose reels to be located inside the building Additional fire extinguishers within the shelter
Health and amenity Ventilation Water and weather proofing Lighting Power distribution Lightning protection Emergency power Toilets and shower amenities Stored water supply Waste water
Ventilation Naturally ventilated during lockdown when the wind gust are gale force or greater (100 km/hr gusts)
Ventilation Venturi duct extraction to toilets Natural ventilation ducts with baffles, wall and ceiling fans Manual louver and damper controls
Ventilation, water and weatherproofing Baffles on inside of louvers Roller shutters on outside of louvers Two stage louvers with plenum for natural ventilation Sarking to roof Construct
Emergency power Generator + Battery backup 24hrs lighting
Ancillary provisions Communications Seating and emergency bedding Kitchen Shelter office Emergency first aid Chair store
Seating and emergency bedding Yeppoon Cyclone Shelter TC Marcia Feb 2015
Design and construction assurance Buildings normal use NCC (incl Building Code of Australia) Cyclone shelter use Cyclone shelter design guidelines
Other guidelines Mitigating the adverse impacts of cyclones: Evacuation and shelter Disaster Management Act 2003 Guideline Queensland Public Cyclone Shelters Maintenance Guidelines Disaster Management Act 2003 Guideline Queensland Public Cyclone Shelters Operations Guidelines Disaster Management Act 2003 Guideline
Thank you Construct