This presentation throws light on some important facts which should be taken into consideration while building any structure to improve its quality.

1. Building Quality Structures

2. Different types of structures we
see around
Our aim is to build a
quality design with low
cost.

3. What is a load?
Load is a force which applies on a structure. Any
structure must withstand different types of forces or
loads.
There are two main types of loads:
Dead load:
This is a permanent or stationary load which can
not be removed.
For example: self weight of the structure
and

4. Dynamic Load: Wind
Rain
People
Loading/Unloading

5. We will study one example to understand the concept clearly.
Imagine that we have to build a structure, a Tractor Shed of following
dimensions.
10 m
Truss
4m
Column
5m
9m
Foundation

6. Main features which will carry the load are:
The trusses – own weight and weight of the roof
The columns – own weight and weight of the trusses
The foundation – own weight and weight of the
trusses and columns
Important rule: Always work from top to bottom
1. Truss
2. Column
3. Foundations

7. 1. Load on Truss
10 m
4 m
Steel Sheet = 10kg/m2
Mass of 1 Truss = 100kg
Area of roof (m2) = 10 m x 4 m x 2 =80 m2
Mass of roof (kg) = 80 m2 x 10 kg/m2 = 800 kg
Weight of roof (N) = 800 kg x 10 = 8000 N

8. 1. Load on Truss 8000N
10m
4m
Steel Sheet = 10kg/m2
Mass of 1 Truss = 100kg
Weight of 1 truss (N) = 100 kg x 10 = 1000 N

9. 1. Load on Truss 8000 N
10 m
4m
Steel Sheet = 10kg/m2
1000 N 1000 N 1000 N
Mass of 1 Truss = 100kg
Total weight on trusses (N) = 8000 N + 3000 N = 11000 N

10. 2. Load on Column Mass of 1 Column = 10 kg/m
8000N
1000 N 1000 N 1000 N
5m
Mass of 1 pole = 5 m x 10 kg/m = 50 kg
Weight of 1 pole = 50 kg x 10 = 500 N

11. 2. Load on Column
Mass of 1 Column = 10 kg/m
11000 N
500 N 500 N 500 N
500 N 500 N 5m
500 N
Load on each column = 11000 N + 3000 N = 14000 N

12. 3. Load on Foundation
Mass of Foundation = 2000 kg
14000N
Weight of Foundations = 2000 kg x 10 = 20000 N
Load on Foundations = 14000 N + 20000 N = 34000 N

13. Windflow over buildings
The diagram illustrates how wind follows in a curved path as it flows over a
building. The effect is the same as in a tornado; towards the centre of
curvature, the pressure drops. The wind causes high pressure on the wall it
hits, and low pressure on the wall behind the building.
low pressure
low pressure high
pressure

14. Greater the
curvature, lower the
pressure and greater
the suction.
As can be seen, a square shaped
building experiences large force,
a pitched roof experiences less
suction, and a domed roof
experiences least force. Dome
shapes have started being used
in hurricane prone regions of
America.

15. So how do I calculate wind load?
What are the things affect wind load?
Size of the building
Height of the building
Shape of the building
Area of roof
Region (some regions are more
prone to wind than
others)
Landscape (wind accelerates over
hills, so a building on a
hill will experience higher
loads than those in
valleys).

16. Maximum expected wind speed in various
regions across India
Zone Wind speed
(m/s)
55
50
47
44
39
33
 Pabal – 39 m/s
Always check this type of
map to see the max.
expected wind speed in your
area. You want to design a
building which can survive
the worst case scenario.

17. Safety Factor
 Wind speed is affected by local terrain
If you are on a hill, increase the wind speed
by multiplying it by 1.1
Design wind speed = 1.1 x 39 m/s
= 43 m/s

18. Wind Pressure
Wind pressure is the force per square
metre on a surface
Pressure (N/m2) = 0.6 x windspeed2
= 0.6 x 43 x 43
= 1109 N/m2
1m
1m

19. Wind Force
 Wind force is the specific force on a particular
part of the building
 Safety Factor: account for internal pressure
changes with a safety factor of 2
Force (N) = Pressure (N/m2) x Area (m2) x Safety Factor

20. Wind Force
Force (N) = Pressure (N/m2) x Area (m2) x Safety Factor
Area Of Wall (m2) = 9 m x 5 m = 45 m2
Force On Wall (N) = 1109 N/m2 x 45 m2 = 99810 N
 Wind Pressure = 1325 N/m2
 Safety Factor = 2
Wind Force (N)
5m
9m

21. Wind Force
Force (N) = Pressure (N/m2) x Area (m2) x Safety Factor
 Wind Pressure = 1325 N/m2
 Safety Factor = 2
Area Of Roof (m2) = 10 m x 4 m Wind Force (N)
= 40 m2 4m
Force On Roof (N) =
10m
1109 N/m2 x 40 m2 x 2 =
88720 N