Design criteria for public cyclone shelters

Design criteria for public cyclone shelters

EHA – WA Conference, Sept 2015

Dr Peter MullinsMullins Consulting

Brisbane

TC Yasi

2nd Feb 2011

Evacuation


• Storm tide inundation

• Vulnerable houses

Tully

TC Yasi Feb 2011

Harvey Bay Storm Tide

Model

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


Tully Senior Citizen Hall

TC Yasi Feb 2011

Innisfail SHS

TC Larry 2006

Innisfail SHS

TC Larry 2006

Purpose built cyclone shelters


Redlynch SC

Tully SS

Innisfail SHS

Proserpine SS

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: V10,000 = 306 km/hr

Region D: V10,000 = 392 km/hr

Wind borne debris


100x50 timber member of 4kg mass impacting at

• 0.4V10,000 horizontal trajectory (Region C 122km/hr; Region D 157km/hr)

• 0.1V10,000 vertical trajectory (Region C 31km/hr; Region D 39km/hr)

Load B: 8mm diameter steel balls impacting at

• 0.4V10,000 horizontal trajectory (Region C 122km/hr; Region D 157km/hr)

• 0.3V10,000 vertical trajectory (Region C 92km/hr; Region D 118km/hr)

Kurrimine Beach

TC Larry 2006Innisfail SHS

TC Larry 2006

Wind borne debris – Tests


solid core door 50mm plywood door steel clad door

4kg impacting at 122 km/hr




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 m2 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

Manual louver and

damper controls

Natural ventilation ducts with

baffles, wall and ceiling fans

Ventilation, water and weatherproofing


Construct

Baffles on inside of louvers

Roller shutters on outside of louvers

Two stage louvers with plenum for natural ventilation

Sarking to roof

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 shelterDisaster Management Act 2003 Guideline

Queensland Public Cyclone Shelters

Maintenance GuidelinesDisaster Management Act 2003 Guideline

Queensland Public Cyclone Shelters

Operations GuidelinesDisaster Management Act 2003 Guideline

Thank you


Construct

Design criteria for public cyclone shelters

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