metal structures and bridges presentation

2. PROFESSIONAL ENGINEERING BRIDGES
We know that bridges play an important part in our daily lives. We know they
are essential components of cities and the roadways between populations of
people.
Some bridges are simple and straightforward; others are
amazingly complex.

3. What are some bridges that you know that
might be called simple bridges?

4. What are some bridges you know that might be
considered more complicated?

5. What makes some bridges simple and
others complex?
• Their size
• multiple purposes
• environmental conditions
• enviromental forces
• material maintenance
requirements,etc.

6. SKY GATE BRIDGE
One amazing example of a bridge's
contribution to connecting people to
other populations and places for both
social and commerce reasons is the Sky
Gate Bridge connecting people to Japan's
Kansai International Airport, located in
Osaka Bay.

7. It is not easy to create a bridge the size of
the Sky Gate Bridge.
Have you ever wondered how engineers
actually go about designing an entire
professional bridge?
Bridges are often designed one piece at a
time.
Each pier (columns) and girder (beams) has
to meet certain criteria for the success of the
whole bridge.

8. Structural engineers go through several steps before
even coming up with ideas for their final designs.
1. First and foremost, engineers
must understand the problem
completely.
.To do this, they ask a lot of questions.
What are some questions the
engineers might ask?

9. 2. Next, engineers must
determine what types of loads
or forces they expect the
bridge to carry.
.Determining the potential loads or forces that
are anticipated to act on a bridge is related to
the bridge location and purpose. Engineers
consider three main types of loads:
-dead loads
-live loads
-environmental loads

10. 3. The next step is to determine if these
loads can occur at the same time and
what combination of loads provides the
highest possible force (stress) on the
bridge.
During bridge design, combining the loads for a
particular bridge is an important step. Engineers
use several methods to accomplish this task. The
two most popular methods are the UBC (The
Uniform Building Code) and ASCE (The American
Society of Civil Engineers) methods.

11. 4. Next engineers use mathematical
equations to calculate the amount of
material required to resist the loads in
that design.
After an engineer determines the highest or most
critical load combination, they determine the size
of the members.

12. 5. After they have considered all of these
calculations, engineers brainstorm
different design ideas that would
accommodate the anticipated loads and
amount of material needed.
Engineers split their design
into smaller parts and work
on the design criteria for all
the components of the
bridge.

13. MAINTENANCE
Bridges represent a considerable capital asset not
only because of the heavy investment required in
constructing or replacing them but also because
some of them form part of the historic and
cultural heritage of a country.
Steel Bridges are subject to gradual
deterioration due to corrosion, mechanical wear,
impact, and fatigue damage from moving loads,
that require periodic maintenance throughout
their service life.
The damage likely to get worse or to expose the
security of the structure to danger, should be
repaired as quickly as possible in all cases.

14. What are the essential processes involved in
steel bridge repair and maintenance?
1. Ocular Inspection
2. Removing and Reapplying Paint
3. Cleaning Exposed Areas
4. Reinforcing Steel Sections
5. Steel Cable Maintenance

15. 1. Ocular Inspection
.bridge maintenance must always begin with an
ocular inspection. The way steel degrades or
deteriorates is mainly due to corrosion i.e. rust.
.You should also be on the lookout for structural
damage such as dents, deformities, chip
damage, and other details that could affect the
structural integrity of the bridge.

16. 2. Removing and reapplying Paint
.If the steel bridge needs to be repainted, the
first thing to do is remove the existing paint
until the bare metal is the only thing remaining.
.Apply one prime coat before anything else
because it is the first layer of protection against
the elements, so don’t go painting before
applying it.
.After it dries, apply two layers of the color coat
of your preference.

17. .Make sure to apply paint seals to the
joints and intersections of the metal
surface so that no moisture can get in
between the metal parts.
.If the paint you are trying to remove has a
lead component, make sure not to inhale
or ingest it to avoid lead poisoning. Try to
be diligent at its disposal as well, so you
don’t cause lead poisoning to other
organisms in the environment.

18. 3. Cleaning Exposed Areas
.Dust, animal droppings, and other forms of dirt
can make your steel bridge look depraved.
When it comes to the exposed areas (which is
pretty much every area of the bridge), use a
pressure washer to ensure that it is cleaned
thoroughly.
.When it comes to cover plates, another widely
exposed part, replace uneven and worn-out
plates if normal pressure washing and buffing is
not enough to maintain its integrity.

19. 4. Reinforcing Steel Sections
.Some sections of a steel bridge might have
weakened due to corrosion and wear, but not all
of them can be replaced easily or in an instant. In
those cases, reinforcing these sections is your
next best bet. You can add extra steel to parts
like the cross-section for reinforcement.
.Be mindful when adding more metal for
reinforcement because the permissible stresses
in the added material must comply with the load
design stresses.

20. 5. Steel Cable Maintenance
.You can maintain steel cables by removing
foreign objects from the cable support system,
cleaning it and lubricating the cable supports.
Tighten or replace stirrups when necessary and
repair the cable wrapping when it is damaged.
.Do not neglect the steel cables just because
they might be a hassle to repair and maintain
due to their placement. They are important in
keeping your steel bridge safe for use.