1. FORCES ON CIVIL ENGINEERING PROJECT
TOPIC 1.2
FORCES ON
CIVIL ENGINEERING PROJECT
BY :
NOR AZAH BINTI AZIZ
KOLEJ MATRIKULASI TEKNIKAL KEDAH 1

2. CIVIL ENGINEERING PROJECT
FORCES ON
CIVIL ENGINEERING PROJECT
LEARNING OUTCOMES :
a) Identify and describe the engineering forces due to;
Physical forces Dead load, traffic loads, imposed loads, hydrostatic/ water pressure, lateral earth pressure
Environmental forces Wind, earthquake, waves, explosion, flood, temperature and pollutants
b) Identify and describe the engineering forces based on chosen case project.

3. INTRODUCTION
In any building design, the strength and stability of an overall building and its individual components must be considered.
This involves structural calculations to work
out the effects of all the forces acting on any component in the building and on the
building overall.
To do this we need to resolve the forces in the system to see what the overall effects
are likely to be.

4. INTRODUCTION
An overview of the many different forces acting on a building.

5. INTRODUCTION
A summary of all the forces acting on the building. The dotted arrow is the resultant force, a force representing the overall effect of the loads.

6. INTRODUCTION Structural Engineering
What does a Structural Engineer do?
A Structural Engineer designs the structural systems and structural elements in buildings, bridges, stadiums, tunnels, and other civil engineering works
Design:
process of determining location, material, and size of structural elements to resist forces acting in a structure 6

7. Examples of Typical Structures7

8. TYPES OF PHYSICAL FORCES
self weight
Dead Load/
Live Load / Imposed load
Traffic Load
Hydrostatic Forces /
Water Pressure
Lateral earth Pressure

9. i) DEAD LOAD Dead loads are permanent or stationary loads
which are transferred to structure throughout
the life span.
Dead load is primarily due to
- self weight of structural members
- permanent architectural component such as exterior cladding, partitions and ceilings
- equipment and static machinery when permanent fixtures

10. A Simply Supported Beam
Tension
Compression
Loads 10

11. ii) LIVE LOAD/IMPOSED LOAD
The total of all moving and variable loads that may be placed upon a building or home
Load that acts on structural component.
Loads produced by use and occupancy of the building structure including weights of movable partitions or furniture etc.
These load are more difficult to determine accurately.
Estimates done on standard codes of practice or past experience. 11

12. Towers: Live and Dead Loads
EXAMPLE
Towers: Live and Dead Loads
Towers serve many purposes. Radio, TV and wireless communication signals are transmitted from towers. Forest rangers keep a vigilant eye peeled for signs of forest fires from observation towers. Skyscrapers serve an important role in the world’s urban areas.
Like other structures, towers are subjected to dead and live loads. In the case of a skyscraper, dead loads are comprised of steel columns and beams, concrete, and glass – the weight of the structure itself. Live loads include the people milling about on the floors and ascending the elevators; plus furniture, materials, and goods that move into the building.
Another important live load acting on a skyscraper is the force of wind blowing against the exterior surfaces. Because the buildings have an enormous amount of surface area, the force of wind on a skyscraper can be extremely powerful.

13. ii) TRAFFIC LOAD
Traffic load is the average number ofvehicles two-way passing a specific point in a 24-hour period, normally measured throughout a year
The standard measurement for vehicle traffic load on a section of road, and the basis for most decisions regarding transport planning.
Road authorities have norms based on traffic load with decisions to expand road capacity. 13

14. COMPOSITION OF TRAFFIC STREAM
Based on the various sizes of vehicles using intersection
PCU (Passenger Car Unit) is used to calculate traffic
stream
Vehicle Type
Equivalent Value (pcu)
Motorcycle
Passenger car
Medium Lorry
Light Van
Bus & Heavy Lorry
0.33
1.00
1.75
2.00
2.25
EQUIVALENT FACTOR FOR VARIOUS VEHICLES RELATIVE TO PASSENGER CAR

15. Traffic Force Transfer Example - Bridge
8,000 lb
32,000 lb
22,000 lb*
18,000 lb**
L = 60 ft
30 ft
15 ft
45 ft
**Front axle: 8,000 lb x 15/60 = 2,000 lb
Rear axle: 32,000 lb x 30/60 = 16,000 lb
*Front axle: 8,000 lb x 45/60 = 6,000 lb
Rear axle: 32,000 lb x 30/60 = 16,000 lb 15

16. ii) LATERAL EARTH PRESSURE
Lateral earth pressure is the pressure that soil exerts in the horizontal plane.
The common applications of lateral earth pressure theory are for :
such as retaining walls, basements, tunnels
i) the design of ground engineering structures
foundation
ii) to determine the friction on the sides of deep 16

17. Lateral Support In geotechnical engineering, it is often
necessary to prevent lateral soil movements.
Braced excavation
Anchored sheet pile
Tie rod
Sheet pile
Anchor
Cantilever retaining wall

18. Lateral Support
We have to estimate the lateral soil pressures acting on these structures, to be able to design them.
Gravity Retaining wall
Soil nailing
Reinforced earth wall

19. Soil Nailing

20. Lateral Support Reinforced earth walls are increasingly
becoming popular.
geosynthetics

21. Interlocking stretchers and headers
Lateral Support
filled with soil
Crib Wall have been used in Queensland.
Good drainage & allow plant growth.
Interlocking stretchers and headers
Looks good.

22. Lateral Support
Reinforced earth walls are increasingly becoming popular.
geosynthetics

23. Lateral Support Crib walls have been used in Queensland.
filled with soil
Crib walls have been used in Queensland.
Good drainage & allow plant growth.
Looks good.
Interlocking stretchers and headers

24. Retaining Walls - Applications
Road
Train

25. Retaining Walls - Applications
highway

26. Retaining Walls - Applications
High-rise building
basement wall

27. Gravity Retaining Walls
cement mortar
plain concrete or stone masonry
cobbles
They rely on their self weight to support the backfill

28. Cantilever Retaining Walls
Reinforced; smaller section than gravity walls
They act like vertical cantilever, fixed to the ground

29. Soil exerts pressures on retaining structures
buckling

31. ii) HYDROSTATIC PRESSURE/
WATER PRESSURE
In a fluid at rest, the weight of the liquidwill create a pressure on the surface of a body.
This pressure is defined as the hydrostatic pressure.
Its depend on density of the liquid and depth.
dam structure.
Normally consider for marine structure and 31

32. Dam Structure
Arch Dam
Cross Section

33. engineering structure due to
Environmental Forces
Forces that acting to
engineering structure due to
environmental factor

34. i) Wind Load Wind Load What it means
positive or negative pressures exerted on a house when it obstructs the flow of moving air.
generally act perpendicular to the surfaces of the building.

35. i) Wind Load What it affects
The significance of the load varies depending on the geographic location of the house, its height, and its roof pitch.
have the most significant impact on roof framing, overhangs, and large openings, especially those near building corners.
On a larger scale, shear-resisting elements, like the roof, floor framing, and sheathed wall segments (shear walls), are affected by wind loads.
Typically, building are designed to resist a strong wind a very long return period, e.g 50 yrs or more.
The design wind speed is determined from historical record to protect future extreme wind speeds.

36. i) Wind Load

40. ii) Earthquake
Also known as quake or tremor.
Is the result of sudden release of energy in the earth crust that causes seismic waves.
Measured with a seismometer
The seismic activity of an area refers to the frequency, type n size earthquake experienced over a period of time.
At the earth’s surface, earthquake manifest themselves by shaking and sometimes displacing the ground.

41. ii) Earthquake
When a large earthquake epicenter is located offshore, the seabed sometimes suffer sufficient displacement to cause a tsunami
The shaking in earthquake can also trigger landslide and occasionally volcanic activity
At the earth’s surface, earthquake manifest themselves by shaking and sometimes displacing the ground.

43. iii) Waves Load
A waves is a disturbance that propagates.
The impact of a pulsed or wavelike load to an engineering stucture.
Commonly used in the analysis of offshore structure, piping and an engineering platform.

46. iv) Flood
Flood is an overflow or accumulation of an expanse of water that submerges land.