On May 19, a document signed for the duty room of the Guangdong Emergency Management Department introduced the situation report of the Huaqiangbei SEG Building. According to the report, experts from the provinces and cities preliminarily believe that one is that the SEG Building trembles up and down instead of swinging side to side, and the other is that the tremor is caused by a combination of multiple factors, mainly affected by wind, subway operation and temperature rise. According to expert research and judgment, the main structure of SEG Building is safe.

On May 18, the Shenzhen Municipal Housing and Construction Bureau notified that the SEG Plaza Building would vibrate from 12:31 to 13:00 on May 18, 2021. After receiving the situation, the building management office quickly notified the emergency evacuation of the people in the building through the floor broadcast, and arranged the staff to guide the orderly evacuation. As of 13:55, all the people in the SEG Plaza had been evacuated safely.

After receiving the report, our bureau immediately organized relevant experts to rush to the scene, and then conducted on-site surveys of the building and housing conditions of the SEG Building, and conducted research and analysis on the incident. After investigation, the building did not vibrate again after 13:30. At present, no safety abnormalities have been found in the main structure of the building and the surrounding environment, no cracks have been found in the surrounding ground, and the indoor steel structure and decorative surface are in a normal state. The specific cause of vibration is still under investigation, and the main structure of the building is safe.

I am registered as a first-level structural engineer, and my master’s degree also studies high-rise design. Let me give you an idea. Subway construction may be a reason. The embedded effect of the base is not so strong, which changes the natural vibration cycle of the SEG Building. It can explain to a certain extent why there was no vibration in the previous twenty years but now there is. There is also a bold guess, just a guess, that is whether sea sand was used in the concrete raw materials of SEG Building at that time. If so, the elastic modulus of concrete may decrease after 20 years of corrosion, which will lead to SEG Building. The natural vibration period of each order of the building has changed. Among them, the natural vibration period of a certain order is just close to the wind vortex or wind vibration frequency or the externally acting frequency, which causes resonance. If this is the case, it is necessary to adopt reinforcement methods to change the current SEG building. For each order of natural frequency, if a damper is added, it must also be a damper that can change the natural vibration period. The viscous damper can only reduce vibration but not eliminate resonance. Of course, it is most likely that various reasons are superimposed together. For example, the load distribution has changed due to decoration, and many new buildings have been built around the SEG Building, which has caused changes in wind direction, wind intensity and wind vortex. Therefore, urban construction is not as high as possible, hahaha.


By zhiwo

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7 months ago

I think this report basically means that some of the expert team thinks it is wind, some think it is temperature, some think it is subway, and no one can convince anyone. There is insufficient evidence due to wind (mainly because the report says that the building vibrates up and down, and wind hardly causes the up and down vibration). As for the subway and temperature, there is no way to verify it. The temperature distribution at the time of the incident cannot be accurately restored, and it is difficult to calculate the influence of the subway on the foundation and then on the superstructure.

7 months ago

The self-vibration period of the super high-rise building of SEG Building is more than 6 seconds. As for the internal vibration video of the SEG Building circulated on the Internet, the internal vibration has a high frequency which is far less than the natural vibration period of the building. Therefore, it is not necessary to consider the free vibration of the building, but it should be a forced vibration with a high frequency vibration source. The antenna on the roof is highly suspect. Under a certain wind speed, the wind passing through the circular cross-section antenna will produce eddy currents. The eddy currents will fall off for a fixed period. If this fall off period is close to the natural vibration period of the antenna, it will cause the antenna to resonate as a source of vibration. Cause vibration in the building. There should be no problem with the main structure, just replace the antenna. An idea above. Hope as a survey

7 months ago

Since the officials have been working overtime to test and say that there is no safety problem, just trust the party and the government and continue to do business normally. After all, the impact of typhoon and other bad weather has been considered at the beginning of the design of a super high-rise building, and the inspection was still carried out at ten o’clock last night, and the lights on the equipment floor were always on. Wind, subway, and temperature are all uncontrollable, so there is no way to prevent it. If you stock up less, you may be fine by changing the natural frequency of the next building.

7 months ago

This is the same as finding that UFO is said to be a meteorological problem. Although I also think that UFOs are not so easy to appear, but it is a bit eloquent to say that experts are facing the photos and say that it is a weather problem. After all, the biggest problem is confidence. I don’t know how long the panic will last. Although many people are not so free and can go wherever they want, they should still stay as far away from that area as possible in the future. Customers and visitors will also be affected. The value of this area and the building will decline until everyone gets used to it and regains a sense of security. Moreover, the person in charge is really hard to find the cause, and at the same time, he is afraid that something really happens and will bear the responsibility, and his life is also uneasy. It’s as if the wall of my toilet is leaking. Don’t tear down the wall and don’t know why. Demolition of the wall is another big project. If you open the wall and find that the water pipe is leaking, it’s okay to change the pipe. But in case water leaks from the exterior wall (affected by the surrounding area, subway, construction on the site), it is not known whether the property is willing to manage it. Because there is no leak in the outer wall, everything is speculated and suspected. What is even more unsolvable is the structural problem. In winter, everyone turns on the heating, and the hot air rises, and when it meets the top of the building, it becomes water vapor. When summer arrived, there was no sign. Even if the cause is determined, can it still be removed and recapped?

7 months ago

I don’t know how the experts judge and whether there are disputes between them, so I have to guess. If I guess, the reason is not determined, but three hypothetical reasons are proposed: wind, subway, and temperature. The specific analysis is as follows: wind. There was wind at the time, but it was not the extreme of historical data, otherwise the other two reasons and coupling would not be assumed. In other words, wind is unlikely to be an independent cause. subway. The subway itself may have an impact, but the subway is more regular than the wind and less prone to abnormalities, so it cannot be an independent cause but a coupling cause. temperature. The temperature should be slightly higher than the historical data, but neither the principle nor the degree of data anomaly supports it as an independent cause. Comprehensive analysis, further analysis of the three hypothetical causes requires theoretical analysis and simulation experiments to be finalized. From the perspective of the expert process and the habits of relevant departments, it is estimated that this will not be likely to be within a week, but it is estimated that it will be between one month and six months, if there is any finality.

7 months ago

I think of the “Singing of the Mayfly” by Galaxy in “Science Fiction World” in ancient times. The caption is as follows: Human society is always repeating without creativity, and I am always so unfortunate: I just started a title called “Go and Get an Arm”, and found Kawabata Yasunari’s “One Arm” (“Take One Arm” I can give you one night”—the girl said); I just started a title called “Tell Me Your History”, and I discovered Sidney Shelton’s “Tell Me Your Dream”; I’ve been ten years I previously conceived a miniature aerospace short story for children, and now I just wanted to write a pen and saw that the miniature was for aerospace in “My dear, I shrunk the child”; I just wanted to write a science fiction novel about bacteria and viruses, just listen. It is said that letters containing white powder have been “popular” all over the world; I wrote this “The Singing of a Mayfly” halfway, and the trash terrorists drove a plane and crashed into someone’s building. It’s ancient enough. You can find the title by searching the full text. The building inside looks like this: it is not too much to call it a castle. In terms of size, it is at least a million times larger than the real medieval castle: the top height is close to 5,000 meters, and the number of main floors has reached thousands. In theory, you can glimpse its gradual height from 250 kilometers away. The magnificent fort roof; it covers an area much larger than half of San Marino’s territory, almost equal to the area of ​​Tuvalu and the Republic of Nauru combined. If the World Trade Center in New York Harbor-I mean before it was hit by the trash terrorists-moved to its side, it would be the grapes next to the watermelon by comparison. However, from the visual effect, it is more appropriate to compare it to the wheat stalk next to the big tree-it is not only an order of magnitude higher than the twin sisters, and its waist circumference is more than dozens of laps fatter. Then the building structure is like this: “This is what the professor means.” The secretary-general stood up to make a round and picked up a pen, “It is like our castle, which is more than 4,000 meters high and bears wind loads every day. According to us The wind conditions in the area are catching up with the highest wind speed and the strongest wind in the middle part of the castle, so the swing will be very large, theoretically the maximum swing can exceed 10 meters. Fortunately, our castle is a pier. This pen is like a stick, so it must be broken. That’s how our castle should limit this swing. This is both a structural need and a psychological need. But for a tall building like our castle, it’s more difficult to reduce the overall swing. So I cut it open to allow a slight horizontal movement between the parts, which reduces the overall strength. Of course, this movement should not be too large, otherwise the floors will be staggered. We use a superconducting magnetic field to limit this This kind of horizontal movement, set up a superconducting layer every certain height-the professor has already said. If the magnetic field is destroyed-for example, the superconductor fails by power outage, then our castle may be in danger.” There was some commotion in the venue. , Maybe someone heard for the first time that this building is not one piece. The professor cheered happily in his heart like a child: it should be! Who told you to not listen to the class well at the beginning! It mentioned the simulation process of a high-rise collapse: “Originally, the dust storm alone would be fine, but as I said earlier, the’rabbit’ has explosives in his hands.” The professor showed another screen, a three-dimensional simulation of the castle, “If he When the sandstorm comes, explosives are set off on a certain part of the floor at the same time-some more critical parts…” Some red circles appeared on the screen, and some circles overflowed this part of the screen. “I asked the computer to figure it out. There are about 20 similar parts.” The professor pointed with the red pointer. “It may be due to the lack of structure and vibration-especially the latter-to increase the horizontal movement caused by the wind. , Eventually causing the building’s center of gravity to shift, and then a chain reaction. And the 496th floor is the most likely one. The probability of the building’s center of gravity deviating from the safety line given by the computer is 76%-already quite large .” The wind started to blow on the screen, and it got bigger and bigger. It can be seen that these winds are ready-made materials that are temporarily used. When the wind entered the peak area, a small explosion occurred at the right time, causing the chain vibration to make the castle laugh as if it had been tickled by someone-smiling and smiling, it fell to the ground. Well, I digress, but I think of this article when I see this kind of problem.

7 months ago

Looking carefully at the conclusions of the experts, we can draw such a conclusion:
What caused the shaking of the building? Answer: Maybe it’s because… Maybe it’s because… What’s the specific reason? do not know!
Will it continue to shake in the future? Answer: Probably it will!
Is the building still safe? Answer: The building is still sturdy, and shaking should…probably…probably…no danger!

7 months ago

The landmark building in Huaqiangbei, Futian District, Shenzhen, the SEG Building over 350 meters high, suddenly shook yesterday. At that time, there was a saying that it was actually related to mining. At the time of analysis, there were 3 possibilities. The first type, the cause of the earthquake, has been ruled out. The second type, the vibration caused by wind, is undetermined. The third type is speculation that it is the co-shock of the hard disk caused by a large amount of mining (such as chia). The third type is spread widely. Why is this? This reason is justified. Because of the doubling of the value of cryptocurrencies, and the price of Huaqiangbei’s most popular single-chip microcomputer such as STM32F103C8T6, the price has risen one hundred times, and the bosses of Huaqiangbei have become billionaires. A certain coin has risen in the last 2 months. The local tyrants of Huaqiangbei are digging a coin in their booths. This coin requires an efficient hard drive, but the supply of ssd coins is in short supply. Smart Huaqiangbei vendors use traditional mechanical hard drives to mine, and the hard drives spin at high speeds. , The number has changed from several hundred to several thousand. Hundreds of thousands of hard drives rotate clockwise at high speed at the same time plus the deflection force of the northern hemisphere to the right, resulting in the resonance of the SEG Building, which is the effect in the video. This reason was widely circulated at the time, because last year’s “undulating” like waves swayed, and also because of an episode. At that time, a 1.2-meter-high retaining wall was added to the bridge deck, which destroyed the streamline of the section and caused it. Vortex vibration. Another reason is that Huaqiangbei is too crazy. The madness of Huaqiangbei. Huaqiangbei, this small land with an area of ​​only 1.45 square kilometers, has found more than 50 billionaires. In 1995, Wu Haijun seized the vane of the electronics market and bought out computer hard drives across China. He made a turnaround in Huaqiangbei and earned 20 million yuan. After that, he founded Shenzhou Computer. In 1998, in a small office in the Huaqiangbei SEG Science and Technology Park, Ma Huateng stayed here for a year, earning his first pot of gold in his life: QQ. During the same period, Zhao Jianjun, a master student who had just graduated from Shanghai Jiaotong University, also went south to Shenzhen and lived in SEG Electronics Plaza. In 1996, PULIAN was established, and its star product TP-Link router was born. With low price and good quality Quality wins the market in one fell swoop. For 30 years, this is a mythical story that has created crazy wealth growth. More attention is paid to the fact that in addition to these super-rich, Huaqiangbei’s greatest strength is that he can always switch back and forth in various outlets freely. From the early copycat market, imitating smart phones and smart accessories are omnipotent. According to media reports, only one week after the release of Apple’s genuine AirPods Pro, some suppliers in Huaqiangbei stated that the first copy of the models had been shipped, and some even commented that “the quality is better than the genuine ones.” In 2017, Bitcoin experienced a surge In the market, the mining machine store in SEG Plaza is very popular, and many stores that originally sold assembled computers have been converted into mining machine shops. Some people joked that people who use mining machines to mine coins can’t make money by selling mining machines. In 2019, domestic e-cigarette production reached a blowout period, and Shenzhen accounted for 90% of the world’s e-cigarette production. Thousands of brands gather in Huaqiangbei, most of which are export-oriented. After September 2020, the “coin market” once again ushered in a new round of bull market, and the “transformation” process of some computer businesses has accelerated. The original computer business has turned into a sideline business, and sellers have changed their names to “mining”. Behind this madness is another frenzy of wealth creation. Not only in Huaqiangbei, but also outside Huaqiang. Since last month, the animal currency has suddenly risen sharply. Shib’s short-term speculation should be the most obvious. On the evening of May 8, SHIB’s value rose by more than 400% in just a few hours. The madness at the time was as if it were in sight. This was a picture that was widely circulated at that time. The 1000 yuan SHIB doubled to 8000w. There are also retail investors who have earned hundreds of thousands of dollars and then began to enjoy life.

7 months ago

Can a reduced-scale model be established according to the existing technical conditions to verify that the cause of the tremor is the coupling of multiple factors, which are mainly affected by wind, subway operation and temperature rise. One can verify whether the conclusion is correct, and the other can sum up experience from the simulation.

7 months ago

AA: Anyway, we checked, but nothing was found. We don’t know if it won’t appear in the future, because we don’t even know why this time.
BB: How do you explain it like the outside world? There must be an explanation, right?
AA: Let’s talk about all the possibilities. Once something happens or there is a great god to investigate and deal with the cause, we will be able to get rid of the pot.
BB: Wonderful duck. So be it, the meeting ends. Time to drink tea.

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