21 L3-Super Structures

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Oxford Read and Discover level 3 Super Structures by Fiona Undrill

Introduction A structure is something made with many parts, like a house, a school, or a bridge. It can be made of different materials like bricks, concrete, glass, wood, or metal. A super structure is very big, very long, or very tall. What structures can you see here? How many parts can you see? What are the structures made of? What other structures can you think of? Discover! Now read and discover more about super structures!

Chapter 1 Tunnels Tunnels go underwater, underground, or through the ground. We use tunnels for mines, trains, and road traffic, or to carry things like gas or water. Tunnels are usually made of metal and concrete. One of the longest tunnels in the world is the Seikan Tunnel in Japan. It's nearly 54 kilometers long! It goes between two islands. It was built because it's too dangerous to travel by boat. The tunnel is for trains, but now many people prefer to travel by plane. One of the longest road tunnels is the Laerdal Tunnel in Norway. The tunnel is nearly 25 kilometers long and it goes through a mountain. It was built because there's too much snow on the mountain roads in winter. Discover! In the tunnel there are three big caves where drivers can stop and rest.

Chapter 2 Bridges Bridges go over water or overground. On a beam bridge, the pillars carry the deck. One of the longest beam bridges is the Lake Pontchartrain Causeway in the USA. This bridge is about 38 kilometers long and it has over 9,000 concrete pillars. It goes over water and carries road traffic. On a suspension bridge, the cables and towers carry the deck. The anchorages hold the cables. Suspension bridges move a little when it's windy. This isn't usually a problem, but in 1940 the Tacoma Bridge in the USA collapsed in light winds. It was only four months old.

Chapter 3 Skyscrapers When there isn't much ground, we can build tall buildings. Very tall buildings are called skyscrapers. The first skyscraper was the Home Insurance Building. It was built in Chicago in the USA in 1885. It was 42 meters tall. The tallest skyscrapers are now much taller than this. The Petronas Twin Towers in Kuala Lumpur in Malaysia are the tallest twin buildings. There is a bridge between the two towers called a skybridge. One of the tallest skyscrapers is the Burj Dubai'. It's in Dubai in the United Arab Emirates. It's 818 meters tall— that's nearly a kilometer! It's made of a special, strong concrete called reinforced concrete. The Burj Dubai has apartments, shops, swimming pools, hotels, restaurants, and a library. It's like a very tall town! Do you like it? Discover! The concrete in the Burj Dubai weighs the same as about 100,000 elephants!