Who built the first bridge? Detailed answer

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Who built the first bridge? Detailed answer

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Who built the first bridge?

To answer this question, we must turn to prehistoric times, since always and everywhere man had to find a way to cross the streams and rivers he met on his way.

Probably, nature itself provided the first bridge for man when a tree fell across a stream. A person could easily copy it. Probably, just such wooden bridges were used for a long time, before some prehistoric engineer came up with the idea of pouring stones in the middle of the stream and throwing logs from them to the banks.

So it turned out a simple girder bridge with one imperfect support. The next step in building a bridge over a wide, shallow stream was to build a few pillars and connect them with logs or stone slabs. Two logs were stacked side by side and crossbars were laid on them as a flooring. The result was a wooden girder bridge, very similar to those still being built across small streams in the countryside. Larger girder bridges are now built on iron beams, while the strongest are built on steel beams.

Bridge spans should not be too long, but where the necessary supports can be built, a bridge of any length can be built. Therefore, many long railway viaducts are just girder bridges.

Any bridge has two main parts - the superstructure and the supports on which it rests.

The bridge piers must be strong, because if they sink or are washed away by water, the entire bridge may collapse. Today, engineers usually strive to set the bridge abutments as deep as possible, and this often involves a huge amount of excavation. For example, during the construction of the Eads Bridge across the Mississippi in St. Louis (Missouri), the supports were dug 40 meters below the water level, and for the bridge across the bay between San Francisco and Oakland - even 70 meters!

Author: Likum A.

Random interesting fact from the Great Encyclopedia:

When was the Capitol in Washington built?

In the Capitol building in Washington, DC, the Congress of the United States of America discusses and passes laws. The Capitol is also the site of the inauguration of the president (the solemn procedure for taking office as the head of state). This huge, impressive building dominates the Washington skyline. Wide streets with radii depart from the Capitol, like the spokes of a large wheel. The foundation stone of the Capitol was laid in 1793 by George Washington.

The main part of the building, made of sandstone brought from Virginia, was built between 1793 and 1827. The wings, which house the Senate and the House of Representatives, were built of white marble brought from Massachusetts from 1851 to 1865. The steel dome of the Capitol, which rises to a height of 86 meters, is crowned with the Statue of Liberty. This statue, by American sculptor Thomas Crawford, was installed on the dome during the Civil War in 1862. Abraham Lincoln oversaw its establishment, and 35 artillery pieces announced the event with celebratory fireworks. The 36 columns surrounding the base of the dome symbolize the states that were part of the Union at the time the dome was built.

The Capitol has been rebuilt several times. It was burned by the British in the War of 1812. The fire destroyed the roof's original timber roofing, much of the interior, and many of the marble columns. In 1961, the East facade of the Capitol was reconstructed. It is on the steps of the East Facade that the President of the United States takes the oath on the day of the inauguration. Near the Capitol are the Supreme Court and the Library of Congress.

The white marble courthouse symbolizes the importance and purity of the law. The country's Supreme Court is located here, where nine judges of the country's highest court meet and sit.

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