1 Foundations
The uplift forces from cyclone winds can sometimes pull buildings completely
out of the ground. In contrast to designing for gravity loads, the lighter the
building the larger (or heavier) the foundation needs to be in cyclone resistant
design. Ignoring this precept has led to some dramatic failure of long-span,
steel-framed warehouses.
2 Steel Frames
A common misconception is that the loss of cladding relieves the loads from
building frameworks. There are several circumstances where the opposite is the
case and where the wind loads on the structural frame increases substantially
with the loss of cladding.
Total loss of unreinforced concrete block
walls and destruction of reinforced
concrete supports
Destruction of expensive timber framed
residence (Bahamas)
Loss of corrugated, metal, roof sheets
Longitudinal splitting of timber rafters
Usually the weakness in steel frames is in the connections. Thus
economising on minor items (bolts) has led to the overall failure of
the major items (columns, beams and rafters).
3 Masonry Houses
These are usually regarded as being safe in cyclones. There are
countless examples where the loss of roofs has triggered the total
destruction of un-reinforced masonry walls.
4 Timber Houses
The key to safe construction of timber houses is the connection
details. The inherent vulnerability of light-weight timber houses
coupled with poor connections is a dangerous combination which
has often led to disaster.
3.5 Reinforced Concrete Frames
The design of reinforced concrete frames is usually controlled by
the seismic hazard. In countries where this is not an issue care still
needs to be exercised to ensure that the concrete frames can
accommodate the wind forces. There have been a few isolated
examples where, ignoring this, has led to disaster.
4. Component Failures
1 Roof Sheeting
This is perhaps the commonest area of failure in cyclones. The
causes are usually inadequate fastening devices, inadequate sheet
thickness and insufficient frequencies of fasteners in the known
areas of greater wind suction.
2 Roof Tiles
These were thought to have low vulnerability in storms but past
cyclones have exposed the problem of unsatisfactory installation
practices.
4.3 Rafters
Of particular interest in recent cyclones was the longitudinal
splitting of rafters with the top halves disappearing and leaving the
bottom halves in place. The splitting would propagate from holes
drilled horizontally through the rafters to receive holding-down
straps.
4 Windows and Doors
After roof sheeting, these are the components most frequently damaged in cyclones. Of course, glass would
always be vulnerable to flying objects. The other area of vulnerability for windows and doors is the hardware
- latches, bolts and hinges.
5 Walls
It is not uncommon for un-reinforced masonry to fail in severe cyclones. Cantilevered parapets are most at
risk. But so are walls braced by ring beams and columns have remained safe
When they are severe!
In what direction did the tropical cyclone move?
A post tropical cyclone is a cyclone that was once tropical (i.e. a hurricane or tropical storm) that has lost tropical characteristics such as a warm core, but stil retains its circulation.
No, a tropical storm and a tropical cyclone are different stages of development in a tropical weather system. A tropical storm can evolve into a tropical cyclone if it intensifies further in terms of wind speeds, typically reaching sustained winds of at least 74 mph.
Yes. if it hits like cairns its a tropical cyclone
Yes, Cyclone Tracy was a tropical cyclone.
Yes, you can use tropical cyclone in a sentence. And here's how you can do so: The tropical cyclone was moving south. The tropical cyclone whipped her hair around.
When they are severe!
In what direction did the tropical cyclone move?
In what direction did the tropical cyclone move?
A post tropical cyclone is a cyclone that was once tropical (i.e. a hurricane or tropical storm) that has lost tropical characteristics such as a warm core, but stil retains its circulation.
Yes, hurricane is a name for a tropical cyclone.
No, a tropical storm and a tropical cyclone are different stages of development in a tropical weather system. A tropical storm can evolve into a tropical cyclone if it intensifies further in terms of wind speeds, typically reaching sustained winds of at least 74 mph.
Yes. if it hits like cairns its a tropical cyclone
A Cyclone or Tropical Storm.
No, in general meteorological terms a tropical storm s a type of cyclone.
A subtropical cyclone is a cyclone that has both tropical and extratropical characteristics.