Note: This article is not news, but popular science on engineering events.
In the bustling Shuicao District of South Korea, the fashionable Sanfeng Department Store is crowded with people. It is the most famous and luxurious high-end shopping center in South Korea. It has 5 floors on the ground and 4 floors underground. The entire building covers an area of 29,000 square meters. It is connected by two side buildings on the south and north wings with huge chrome-intact glass in the atrium. The north building is a shopping area and the south building is an entertainment area. The interior is luxuriously decorated and the wall decoration is Italian pink marble. All medium and high-end products for sale. There are both domestic products and imported products. The swimming pool, gym and other entertainment facilities are advanced and complete. It is a frequent consumption place in South Korea.
As a top shopping paradise in South Korea, Sanfeng Department Store receives an average of about 40,000 customers per day. At 7:00 am on June 29, 1995, the fifth-floor restaurant began daily preparations. At this time, the restaurant owner found that a huge crack appeared around a pillar in the restaurant, and the width could be stuffed into a fist. In addition, the floor also began to sink, and he couldn't help but feel frightened. He immediately reported this abnormal situation to the mall manager Mr. Li.
What Mr. Li thought of was not to report the situation to the leadership and conduct a safety investigation on the building. He did some calculations in his mind. If the department store was closed today, it would be a loss of 500,000 US dollars. Thinking of this, Mr. Li's flesh couldn't help but hurt.
He immediately came up with an idea in his mind, notifying the restaurant owner to temporarily close the restaurant and put on a warning for construction. On the other hand, for the reputation of the mall, all insiders should not talk to the outside world.
But the crisis will not disappear out of thin air just because of tight silence. At 12:30 noon, guests on the fourth floor began to hear strange sounds and felt the slight vibration of the building. After they informed Mr. Li, Mr. Li still did not feel the danger approaching step by step. He thought there was a problem with the air conditioner on the rooftop, so he just turned it off and did not take any warning measures. Of course, Mr. Li still informed the high-rise of Sanfeng of the building.
At 2 pm, Li Yu, chairman of Sanfeng Group, convened all supervisors to discuss measures for cracks and vibrations in the building. They invited Li Hezhu, a structural engineer in charge of building the building, to check the cracks.
Li Hezhu found that the crack had expanded to the roof of the entire building, and some areas also experienced small collapses. This is not a trivial matter, and Li Hezhu believes that the building should be closed immediately and urgently repaired. But his proposal was quickly rejected because management was reluctant to lose a substantial turnover of the day. But what they don't know is that this decision will cause even more terrible consequences.
At 5:47 pm, as the peak passenger flow period of the day, a total of 1,500 people entered the department store. At 5:52 pm, when everyone was relaxing and shopping happily, the disaster came. The entire five-story shopping mall collapsed in 20 seconds, and even fell into the 4 underground floors. , once a prosperous commercial paradise in Seoul, turned into twisted steel bars and rubble. Under 42,000 tons of rubble, 1,500 people were buried alive. This incident is also known as the number one tragedy in South Korea. (This is the worst disaster accident in the non-war period of the Korean country. It was also the world's most serious safety accident of building collapse on its own. The property losses reached 270 billion won. Therefore, it is officially called the No. tragedy in South Korea's history by South Korea)
Countless citizens who learned about the collapse news gathered around the ruins. There are spectators who simply watched the tragedy of . Of course, more of the families of the victims. They cried and snatched the earth because of the blood of the relatives lying under the ruins. They knew nothing about their life and death.
. The survey results show that this is not actually an accident, but a naked "murder".
The building crushed by air conditioning is behind the naked "murder".
Sanfeng Department Store was built by Sanfeng Group, and and were originally designed. This was originally a 4-story building used as an office, but after the first contractor laid the foundation, Sanfeng Group asked to significantly change the design, not only to change it into a shopping mall, but also to add another floor to the ground building. Since the contractor did not agree to such a modification, Sanfeng Group simply replaced the previous contractor with its own construction company.
such changes have led to many load-bearing columns being replaced by escalator . In addition, because Sanfeng Construction Company arbitrarily changed the building drawings, it turned out that the columns should have a diameter of 80 cm and a total of 16 steel bars, but the actual columns have a diameter of 60 cm and a total of 8 steel bars. In addition, the steel bars in the concrete floor slab are not placed in the correct position, and the and the adopted by Sanfeng Department Store is a Flat slab structure, without beams, and the floor slab is directly supported on the columns.
Therefore, the instability of the support part of a column can lead to the instability of the entire building instability in an instant. This requires accurate design and construction and high quality requirements to ensure the safety and stability of the building. The failure to place the steel bars in the correct position directly causes the strength of the floor slab to drop by 20%, and these are exactly the connection points between the floor and the columns, from which the pressure is transmitted to the ground. During the construction process of
, the 5th floor was originally planned to set up an ice rink, but it was later changed to 8 restaurants and halls. Because Koreans have the habit of sitting on the ground while eating, a layer of heating equipment is added under the concrete floor of the restaurant, which greatly increases the burden on the load-bearing structure. The reason why the building collapse is directly caused by the air conditioner. The air conditioner equipment of the entire building is now installed on the roof. The total weight of 3 large air conditioners is 29 tons.
In 1993, because residents complained about the noise of the air conditioner in the building, Sanfeng Group decided to move the air conditioner in a place, but did not use a crane when relocating, but used pulleys to push the air conditioner weighing 29 tons. Because it was too heavy, cracks appeared to be there where the air conditioner passed by. Among them, the columns of the restaurant in the fifth floor of were particularly damaged. The air conditioner was dragged to the other side of the roof, causing irreversible damage to the building structure. After the air conditioner is filled with water, the weight of the air conditioner reaches 87 tons. The ground is seriously damaged, and the load-bearing columns are reduced, so the building cannot hold it at all.
In the past two years, the vibration caused by turning on the air conditioner will cause the cracks to spread. After being under the heavy pressure of air conditioning for 6 years, Sanfeng Department Store finally couldn't hold on and collapsed, which led to the number one tragedy in Korean history.
Summary
is on the verge of crisis. The dizzy capitalists bet on the safety of more than a thousand people for the sake of profit . The accident will indeed make people learn from the lessons, but the tragedy of greed will not go far. After the
accident, South Korea began a new wave of strict building inspections nationwide, and found that one of every seven high-rise buildings needs to be rebuilt, and four-fifths of the buildings need to be renovated, and only 2% of them are considered safe.
As a result, the fig leaf of South Korea's rapid economic development was ruthlessly lifted. In less than two years, the financial crisis that swept across Asia spread to South Korea. South Korea, which has developed rapidly for more than 30 years from the 1970s to the 1990s, has actually been footnotes behind this seemingly unrelated building collapse accident.
This accident has taught those developing countries that are moving forward rapidly, that is, the continuous acceleration of urban construction should be based on stability and security.
