bridge? The definition of Baidu Baike is a large structure used to cross obstacles. Generally speaking, it is a large building that crosses rivers, canyons and straits or highways and railway lines!
But there is a bridge in Honduras, which is definitely not a headache, because it is built on a huge tidal flat, and on the other side of the bridge is the galloping Choluteka River, which makes people not touch the headache! But for the Honduran people, there is an extremely sad story here.
After a hurricane, the Cholutka River was scraped away.
There is a Cholutka River on the border between Honduras and Nicaragua. It flows through the city of Cholutca. In 1930, the local government built a bridge on the bridge for convenience. A suspension bridge. However, due to the fierce rainfall during the rainy season in Central America, the suspension bridge was repeatedly destroyed and repaired. Until 1996, the local government hired a world-class architectural design to improve the repairs. Division, rebuilt a bridge on the Choluteka River that can handle the once-in-a-hundred-year hurricane weather!
Soon after the construction of the Choluteka Bridge, the local government and the construction company held a grand opening ceremony. Government officials and construction company leaders attended the opening ceremony, and the enthusiastic speech may never be again. The promise that was broken, and in fact the promise was fulfilled! Hurricane Mitch struck
and the bridge was not destroyed. The Choluteka River ran away. Z1z
Hurricane Mitch in 1998 may not be familiar to everyone, but for Central America, this is one of the most devastating hurricanes in the Atlantic hurricane season, the biggest The wind speed reached 290 km/h, and its record was not surpassed by Hurricane Wilma until 2005!
On October 26, Hurricane Mickey reached the highest intensity
On October 22, 1998, Hurricane Mickey formed in the Caribbean Sea. After the huge energy provided by warm water vapor, it exploded into the highest level of Saffir-Simpson Hurricane in a few days. The fifth category, which is commonly known as a category five hurricane! Another characteristic of Hurricane Mickey is its very slow action. It has passed through Honduras, Guatemala and Nicaragua for a very long time, bringing devastating rainstorms to Central America!
Route of Hurricane Mickey
According to local weather station reports, the maximum rainfall exceeds 1,900 mm, which is almost equivalent to the four years of rainfall in Beijing, the capital of my country. More than 11,000 people died in several Central American countries, and another 11,000 were missing. 2.7 million people were left homeless and the total economic loss exceeded 6 billion US dollars!
Of course this loss also includes the Choluteka Bridge, but it is surprising that the Choluteka Bridge withstood the torrential rains of Hurricane Mickey, and the flood on the Choluteka River. After the hurricane, Choluteka. The bridge stood majestically, but the local people were horrified to discover that the Cholutka River was no longer under the bridge, but ran several hundred meters away, where the approach bridge was originally built!
rainfall distribution of Hurricane Mickey.
Cholutka Bridge became a decoration, and the local people soon discovered that the water of the Cholutka River was soaring, and a large amount of impacted sediment was deposited. It happened to be a bend under the Cholutka Bridge, so the river was constantly scouring the river bend. On the outside of the road, on the inside, a large amount of sediment carried from the upper reaches is continuously accumulated!
As a result, a large amount of silt under the Cholutka Bridge formed a tidal flat, while a new river channel was formed at the approach bridge that was washed down on the other side! By now the Choluteca Bridge has become a stalk, meaning that accidents often happen from places you can't think of, like the Maginot Line, or your indestructible business plan! Z1z
Extended reading: The bridge was blown down by the wind
At 14:00 on May 5, 2020, the Humen Bridge appeared resonant wave-shaped jitter, and then the bridge was closed. According to bridge experts, the bridge was changed by the installation of water horses. The aerodynamic shape of the steel box girder creates a vortex vibration phenomenon when the air flows through the bridge. This is self-limiting, which means that the vibration amplitude will not increase with the wind speed, but will gradually become smaller after the resonance point is separated. The bridge resumed traffic on May 7.
Tacoma Strait Bridge,The first bridge to be blown down by the wind
This must be a shame in the bridge industry, because the Tacoma Strait Bridge is the first reinforced concrete bridge to be blown down by the wind. Construction began in 1938 and was designed by the famous Golden Gate Bridge. One of the divisions, Lyon Moisevre, was responsible for the design. At that time, Clark Eddrich also designed to compete with it. However, in order to reduce the cost, Aon Moisevre reduced the bridge deck from 7.6 meters to 2.4 meters, and the cost was reduced from 1100 Ten thousand dollars reduced to 8 million dollars!
and what’s even worse is that he passed the halo design of the Golden Gate Bridge. The bridge was opened to traffic on July 1, 1940, but a few weeks after it was opened, it was discovered that the bridge deck would sway in the strong winds of the Tacoma Strait. And the amplitude is getting bigger and bigger, and the designer who feels bad is using all technical means to reduce the shaking amplitude, but all is to no avail!
On November 7, after shaking for several months, the bridge finally flew up and down in a strong crosswind. The concrete pieces on the bridge deck fell, and the collapse of the entire bridge was captured by cameras set in multiple directions. It is one of the must-see documentaries in the bridge industry and aerodynamics industry! The reason for the collapse of
is simple. Due to the thin bridge deck, the strong crosswind of the Tacoma Strait caused the bridge deck flutter, which is more terrible than vortex vibration, because its amplitude will rise with the increase of wind speed, and finally Exceeding the strength limit of the bridge in a large shock, collapsed and disintegrated!
New Tacoma Strait Bridge
Of course, the Choluteca Bridge in Honduras in this article is not a design problem, but Murphy's law. There will always be worse than you think. How to deal with it?
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-