2. What is Wind Load ?
The term ‘Wind Load’ is used to refer to any pressures or forces that the wind
exerts on a building or structure. There are actually three types of wind forces
that would be exerted on a building.
1 ) Uplift Wind Load :
Uplift Wind Load is an upwards force of the wind that would affect roof structures
or similar horizontal structures in a building, such as canopies or awnings. The wind
flow under a roof structure pushes the roof upwards, the wind flow over the
horizontal structure pulls the roof upwards.
2) Shear Wind Load :
Shear Wind Load is a horizontal pressure or force that can cause walls or vertical
structural elements to tilt or crack, causing a building to tilt.
3) Lateral Wind Load :
Lateral Wind Load is another horizontal wind pressure that can make a structure move
off its foundations or overturn.
3. The actual effects of these wind
forces on houses depend on their
design, construction and
surroundings. Among other things,
high wind pressures tend to collapse
garage doors, window units and
doors, rip off roofing and roof decking
and destroy walls. Roof overhangs,
awnings, porches and other features
that tend to trap air beneath them,
resulting in high uplift forces. In
addition, broken windows and doors
can expose your home to serious
damage from internal wind pressures
and water entry. The actual effects of
wind forces on farm buildings depend
on their design, construction and
surroundings. Local windbreaks –
trees – can help to reduce these
effects.
5. Damage Location
Uplift can develop when wind blows across a roof.
The location of damage on a home will be affected by the orientation of the
wind to the roof structure, and by the shape of the roof. In these areas of uplift
are shown in blue.
HOW WIND CREATES DAMAGE ?
6. General idea:
Wind has two aspects :
The first one-is that its energy can be utilized to generate power, sail
boats and cool down the temperature on a hot day.
The other one -is that it loads any and every object that comes in its way.
The latter is the aspect an engineer is concerned with, since the load
caused has to be sustained by a structure with the specified safety. All civil
and industrial structures above ground have thus to be designed to resist
wind loads. This introductory note is concerning the aspect of wind
engineering dealing with civil engineering structures.
7. Wind flow generation is on account of pressure manifests itself into
various forms, such as :
1) Gales
2)Cyclones/Hurricanes/Typhoons
3)Tornados
4)Thunderstorms
5)Localised storms
