Structures are designed to be much stronger than they need to be, in order to survive things that we don't expect to happen, but might.
Structures are built using everyday shapes and simple machines like pulleys (2 3 4 5), levers, gears,(2 3 4 5 6) wheels and axles, inclined planes, screws and wedges. The most common shapes to use are squares, rectangles and triangles. Triangles and arches are the strongest shape. You can find triangles everywhere! Even in the design of roller coasters (1 2 3 4 5)!
Before we build a skyscraper, we have to use a crane. Cranes are made of squares and triangles. Mobile cranes are on the backs of large trucks and can be moved to where they are needed. Tower cranes are built from the ground up and are much larger and more dangerous than mobile cranes. Tower cranes are needed to build the world's tallest skyscrapers.
There are many very tall buildings on our planet. Some of the tallest include the Q1 in Surfers Paradise Australia, the CN Tower in Toronto and the Burj Dubai in Dubai. These structures need to be very stable in order to stay standing. The CN Tower can withstand winds up to 300km per hour before it gets damaged. Cool!
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Bridges are also strong and stable structures. There are many different kinds of bridges. Some are arches, some are cable-stayed, some are suspension. The largest arch bridge in the world will be built in Dubai. It is very important to build bridges properly because we don't want them to fall down! Some bridge building techniques are thousands of years old.
Aircraft are often needed to build large structures. They can be used to transport building materials, workers and supplies. Aircraft are also structures themselves. They are flying structures! Aircraft have been in use for over one hundred years. They have many uses, from construction to transportation to entertainment. Sometimes the ultimate luxury can only be found in the sky...
