In recent years, my country's infrastructure capabilities have been continuously improved and are recognized as an "infrastructure maniac". India is very dissatisfied with this and directly announced a " Five-Year Plan". claims to invest nearly 10 billion rubles in the infrastructure field to build a brand new India, so as to surpass my country in the infrastructure field and become the number one in Asia's infrastructure. However, due to innate defects, India's infrastructure has never been on the table. For a long time, when talking about Indian infrastructure, we will think of the "tofu" project. Either something happened in the reservoir today or the dam collapsed, which is really worrying. Recently, another bizarre accident occurred. The "Bihar Bridge" that the Indian people are proud of collapse collapsed. The bridge has only been passed for 29 days. The cause of the accident is also a huge joke. actually made the mouse take the blame !
Bihar Bridge collapsed
India is the saying, it’s not good to do anything, bragging first place, India’s face is thicker than that city wall, and has always boasted about its infrastructure strength, but India’s infrastructure not only did not give its own country a face, but also a slap in the face! This was not taken for 8 years and the Bihar Bridge, which cost 26.34 rubles, collapsed in less than a month. After the bridge collapsed, local officials explained that it was because of the recent continuous rainfall in Bihar , causing huge floods, causing water levels to rise, and the water flow rate through the bridge accelerated, and the river bank could not bear huge pressure, causing the earthwork on the north side of the bridge to be washed away and collapsed. As the leader of the Bihar Conference opposition, Yadav, strongly criticized this matter. He claimed that this was a huge corruption. The bridge had been built for 8 years and had not survived for even a month. After the accident, local officials also gave this vague explanation, which was difficult for people to understand, but a discerning person could tell at a glance that it was an excuse.
The dam was destroyed in India for 42 years and was destroyed in
There are many tofu projects like India. In September 2019, a dam in Jharkhand, India was "successfully" completed. The total construction period lasted 42 years, nearly 5 times more than the construction of the Bihar Bridge, and it cost nearly 22 billion rubles. As a result, less than 24 hours of operation, the dam collapsed, causing a devastating blow to nearby farmland and townships. After investigation, it was found that the reason given by the government was that because the construction time was too long, many places of the dam had become homes for mice and ants. This is a typical "a thousand-mile dike, destroyed in an ant hole" modern reverse textbook! of course, the main reason is that no one accepts or inspects the case before receiving it, which leads to a global "famous" tofu case. Through this incident, we can see what kind of attitude India is in treating infrastructure projects.
It is worth mentioning that the bridge is slightly better than the dam that has been built for 42 years. It has been at least a month. India's infrastructure has made great progress, and the reason for the collapse of India's bridge was not blamed for rats. You should know that in previous infrastructure collapse accidents, Indian officials always used rats as shields. In addition to rats taking the blame for India, India's "god" is also very hard. In , the overpass collapse accident in 2016, 26 people were killed and 150 people were injured. Prime Minister Modi of India responded to this: This is God's will. The Prime Minister said so, so it is not surprising that the mouse came out to take the blame when the bridge collapsed.
The reason for the collapse of Indian bridges many times
To put it bluntly, there are people in India doing some improper activities. The quality of the bridge that has been built for 8 years and cost hundreds of millions of dollars should be guaranteed. Furthermore, the flood in India is not a rare natural disaster . At the beginning of construction, the impact of local weather conditions on the bridge should be considered. If a newly built bridge cannot resist floods, what is the point of construction? The collapse caused by natural factors cannot be established, so there is only human factors, that is, the corruption problem in India. Due to corruption, the project funds invested in construction will become less, which will lead to a series of problems, such as: raw materials are inferior as good, and employed workers have poor skills. The result is that there are many "scramble" projects built.
Tacoma Bridge in the United States
. Similar situations have occurred in the United States far away from the ocean. The Tacoma Strait Bridge in the United States spent millions to be built. It was blown off by the breeze after only 4 months after it was opened to traffic. It was also called "Danced Gotty" by local residents of the United States. This bridge was the third largest suspension cable in the United States at that time. The bridge was once called "HTM1 Pearl Harbor in the engineering community". The earliest construction of this bridge can be traced back to 1889. At that time, someone proposed to build a trek on the Tacoma Strait. The completion of the bridge will greatly facilitate the transportation of the US Navy's shipyard in Bremerton and the Army's military base in Tacoma. Therefore, the construction of the bridge also received strong support from the US military, but at first it was not started due to funding issues.
construction cut corners
It was not until 1937 that the bridge began construction. According to the original plan of Washington State engineer Clark Eldridge, the United States allocated $11 million to build the bridge. Later, engineers from New York came to Leon Moiseff believed that it had a better solution. Moiseff planned to use 2.4 meters of ordinary steel beams instead of the original 7.6 meters of truss beams. Not only can the construction cost be reduced to $6.4 million, but it can also make the bridge more elegant. But what everyone did not expect was that Moisef's plan was approved, which will also lay the groundwork for the end of his career. He has abundant funds, and the designers are also an elite in the industry. Construction workers do not cut corners or commit fraud in violation of regulations, but this still cannot prevent the bridge from collapse. After it was completed and opened to traffic on July 1, 1940, it was blown off by the breeze in just four months, and the bridge has become a laughing stock in the world.
Just after the bridge collapsed, the United States specially formed an accident investigation committee and began to investigate. Soon the cause of the accident occurred. The reason was related to Moisef's design. The bridge width was only 11.9 meters, which was rare for the suspension bridge of the same period. Not only was the bridge deck too narrow, but the 2.4-meter steel beam could not produce enough stiffness in the bridge body. Then Carmen then started testing the model in the wind tunnel of the California Institute of Technology, and learned that the culprit of the accident was Carmen Vortex Street. Carmen Vortex Street was also a key consideration when building bridges. It is actually an important phenomenon in fluid mechanics.
Carmen vortex street phenomenon
0 In nature, for example, insert a wooden pile into the water flow, under specific conditions, two asymmetrically arranged vortexes will be generated on both sides of the downstream of the pile. The two rows of vortexes rotate in opposite directions and are arranged interlaced, just like the street lights on both sides of the road. In this accident, if the original plan is used, the wind can pass freely between the truss beams, but after being replaced with ordinary steel beams, the wind can only pass through both sides of the bridge, which causes the Carmen vortex street phenomenon.
Carmen vortex street phenomenon
Because Carmen vortex street has regular periodic phenomena and has a certain frequency, and the Tacoma Bridge itself also has its own frequency, so when the two frequencies are close, resonance will occur, and the consequences of resonance will occur. I think everyone should know, so the reason for this accident was that people knew very little about the aerodynamics and characteristics of the suspension bridge at that time, which caused this disaster.
