Ever wonder how tall buildings can withstand windy days, or why bridges don't collapse when large trucks drive over them? The answer is structural engineering. Structural engineers use physics and math to design and analyze the sturdiness of structures, things like bridges, buildings, concert stages, and even rollercoasters. Don't get me wrong. Designing any one of these things can involve multiple types of engineering, but it's structural engineering that's responsible for making sure that that structure won't collapse or fall over. You see, a structure must be able to handle the forces or loads that it's likely to experience. Take a skyscraper, for example. It not only has to support itself, but also all the people and furniture inside the building, and then external factors, like wind, snow, or an earthquake.
The materials and geometry that make up a structure influence how it may respond to those forces. Different materials have different properties, like strength, weight, and flammability, that can influence a structure's sturdiness. For example, steel is generally stronger, and weighs more than wood, and different geometric shapes work better for different purposes. For example, a square or rectangular base can typically hold more weight than a triangular base. Structural engineers perform calculations to determine the best materials and shapes to use in order to build a study structure. The next time you find yourself at the top of a rollercoaster, you can thank structural engineers for doing their part to make sure it's nice and sturdy.
Now, let´s make some exercises:
Task 1: Key words.
Divided in groups of four, you have to identify the six words that you consider to be the most important.
You can debate with your partners and after 5 minutes the class will be brought together. Every group will write on the board their words explaining the reason. Each word will considered in turn with the group who nominated it will be asked to justify its inclusion.
Conclusions will be written on your notebooks.
Task 2: How many forces do you know?
In groups of four, follow the next steps...
Draw on your notebook a structure. It can be a bridge, a house, a sckyscraper, a tower from the middle ages, a minecraft building, whatever.... Don´t take to much time drawing, it´s just a sketch.
Once it is done, draw in different colours all the forces that you think might affect the structure: weight, wind, earthquake...
Talk and debate with your partnerts and think how each force behaves.
Now you are going to tell to the rest of the class how your structure works.
Task 3: Types of bridges
why are there so many different types of bridges?
why don't they just use one time a bridge?
is a structure that can carry a road, Pat railroad or canal over rivers, canyons and other obstacles.
we need different types of bridges because every design is differet: in loads it will carry, in what will cross it and the earth materials.
bridges can be up to several miles long and take years to construct their amazing pieces of engineering and architecture
tension and compression:
bridges use two main types of forces to carry the loads, tension and compression
compression is a pushing force while tension is a pulling force
beam bridges: is one type of bridge engineers and architects use.
It is one of the simplest structural forms. All you need to construct of beam bridge is a rigid horizontal structure and two vertical supports
one on each end. For example if you were to cut down an apple tree and use that wood to create a horizontal structure and two vertical
supports, now you have a bridge that someone can walk on
arch bridges are made up of half circles that distribute the load gradually toward each side to the ground
they look impressive but it's important that the connection to the ground has support from the sides
otherwise the forces will break the arch. This is why rows of arches called arcades are used a lot.
The ancient Romans were famous for the use of arches in their bridges and even used them to deliver water over hundreds of miles to their
Arch bridges are good to use when designing overall value.
suspension bridges: suspension bridges use a system of cables to support the structure and because of their strengths can spend up to
suspension bridges are very complex and have lots of parts which means that can cause a lot of money
suspension bridges can be used to span across large water masses
the road is suspended by vertical cables that hag from an even thicker cable that
spans between two huge towers the weight of cars pushed out on the bridges deck
and then travels up the cables which transfers the load to the towers
then the tower send the low to the ground an example of the suspense bridge
is the Golden Gate Bridge in San Francisco
cable-stayed bridges cable-stayed bridges may look like suspension bridges
but don't let this food cable-stayed bridge is different from suspension
bridges and that they don't require anchors or multiple towers
instead cables run from the roadway up to a single tower that bears the weight
of the entire structure cable-stayed bridges can be used in applications that
need to cross large spans a unique example of a cable-stayed bridge is the
puente del Alamillo
with so many options how do engineers and architects
choose what type of bridge to use from the beam bridge to the suspension bridge
to arch bridges and cable-stayed bridges each situation has its unique qualities
in each bridge has its strengths and weaknesses as well it depends on several
variables including cost location function and design preference
now you are all bridge experts
I hope you have enjoyed this lesson on bridges and go