On the evening of 18 may, the sage house vision. Covered news profile
On 18 may, there was considerable concern about the shaking of the saig square building, a landmark in the north of shenzhen。
On the evening of 19 may, according to shenzhen, commissioned by the shenzhen city housing department, a number of professional bodies carried out real-time monitoring of the vibrations, tilts, depositions, etc. Of the sage building from 21 p. M. To 15 p. M. On 18 may, all three indicators were considerably lower than the normative permissible values, and the monitoring data did not reveal anomalies。
In fact, shaking and vibrations in buildings such as buildings and bridges are not uncommon. In 2020, the great tiger gate bridge in guangdong had been shaken by wind conditions, in 2019 by typhoons affecting the central building of shanghai, china's first high-rise building, and on several occasions by typhoons and earthquakes in taipei's famous landmark, building 101。
Shenzhen saig building, 19 may. Covered news profile
Preliminary expert investigation:
Sage square's tremors are mixed, mainly by the wind
Shenzhen saig square was completed on 29 june 1999 as a landmark building in the north of china on “china electronics first street”. Information from the network of officials of the south china branch of the china ii bureau indicates that saig square, which covers an area of 9653 square metres, the 72nd floor, 353. 80 metres high, the 4th floor, 19. 5 metres deep, and the total building area of 169,000 square metres, is the world's highest steel tube structure in the world, using a frame structure system and steel tube poles and beam assembly structures。
On 19 may, according to numerous media reports, a report from the emergency management department of guangdong province on the swinging of the sage square building in fukuda, shenzhen city, fukuda street (resumed ii) revealed the preliminary findings of the relevant units, experts from scientific institutions. According to the report, the experts initially believed that the cause of the convulsion of the seger square was a combination of factors, mainly the effect of the wind, and also the effects of subway operations and temperature. “according to the findings of provincial and municipal experts, it is prima facie: first, that the shenzhen saig building is a chain of tremors rather than a left and right shaking; second, that the tremors are caused by a combination of factors, mainly the influence of the wind, as well as by the effects of the operation of the subway (the two subways passing through the floor) and the temperature (the temperature has increased by up to eight degrees in the last two days, which has had a significant impact on the steel structure); and third, that the main structure of the seng building is secure, with a solid internal structure and well-established various ancillary facilities, as determined by experts on site and in consultation with experts.”
According to expert measurements, the sage building is currently tilted between 0. 01 per cent and 0. 02 per cent, less than the allowed slant of 0. 2 per cent and much less than the normative requirements, and the experts agree that the sage building is not tilted. In view of the fact that the building is not equipped with a barrier, the experts suggest that the next step could be to consider the installation of a barrier to increase wind resistance and comfort。
The night view of the shanghai central building. Maps on the news
High-rise shakes are not unusual
In fact, in many parts of the country, as well as in places such as seoul, korea, there have been high-level building shakes in recent years. In an interview, hao shao bo, associate professor, college of architecture and urban planning, china university of science and technology, stated that high-rise swinging was normal and would be influenced by high air and wind. From a structural point of view, the building is designed and constructed in such a way as to account for the swing of the building. The higher the move, the more obvious, is the “lashes effect”, and most of the upper buildings are steel structures that buffer the side pressure。
On 29 august 2019, there was a shaking of the yuguk building in shenzhen lake, where people were able to feel a clear sense of shaking at the top. After that, shenzhen officially issued a circular stating that the structure of the yugyu building was secure and that shaking was linked to the vibrating conduction that had resulted from the demolition of the peaceful new apartment building on which it was tilted。
In 2019, supertyphoon lechma landed on the south-eastern coast of the country, which affected china's first high-rise building in the centre of the sea, up to 632 metres. The structural technical director of the shanghai centre building, song weining, stated that it had been measured that during the period of the lichma's influence, the blocker, which had been dubbed the shanghai centre building's “decorator”, had been unilaterally set at more than 50 centimetres, with an instant peak of 70 centimetres, the largest record since the building was inaugurated. And the one-metre limit for the blocker is one metre。
Prior to the “licima”, the greatest display of the blocker was during the impact of typhoon anbi and wimbia in 2018 — a unilateral display of more than 40 centimetres. At that time, the prevailing wind in shanghai centre was at a rate of more than 20 metres per second. Experts have estimated that, as a result of the typhoon, the entire building was set at 40 and 50 centimetres vertically。
On 8 february 2013, the 41st floor of the shanghai information building, where people above the 20th floor were exposed to intermittent shaking, was subsequently evacuated. Experts subsequently explained that there might have been a resonance between the unknown source and the building, leading to shaking。
On 4 september 2013, a 50-storey writing building at the corner of the new street in jiangsunanjing experienced a number of more visible up and down shakings, which continued intermittently for about an hour. According to yang's evening newspaper, experts from the emergency response unit of the nanjing earthquake bureau stated that there had been no earthquake around the area at that time and that construction was likely to cause vibrations。
On the morning of 5 july 2011, a 39-storey building in seoul, the capital of korea, was shaken for about 10 minutes and subsequently closed. After the incident, guangjin district of seoul indicated that an emergency security check had been carried out on the building and that there were no major structural security problems. According to experts, some of the people in the building were practicing tactile exercises, which coincided with the inherent frequency of the building or led to a shaking as a result of the resonance。
Guangdong tiger gate bridge. It's a big story
The guangdong tiger gate bridge vibrates attention: wind causes vortex jin
In addition to the high-rise buildings, there are also occasional vibrating bridges。
On 5 may 2020, there was widespread concern over the rollover of the bridge between the guangdong tiger gate bridge, which links both sides of the river。
The transport department of guangdong province and the provincial transport group organized overnight a study by 12 well-known bridge experts in the country on the vibrating phenomenon of the tiger gate bridge. The initial judgement was that the bridge vortex was a phenomenon and that the suspense structure was safe and reliable and did not affect the structural safety and durability of the subsequent use of the tiger gate bridge. The main reason for the vibrations was the continuous installation of water horses along the cross-boundary fence along the bridge, which changed the aerodynamic shape of the steel beams and created a bridge vortex under certain wind conditions。
According to a professional on the tiger gate bridge bridge, the suspension bridge is generally divided into two types of vibrations, vibrations and vortexes, which have an impact on the bridge structure and can damage the structure, while the vortex has no impact on the bridge structure and only affects the comfort of the vehicle. The most visible feature of the vortex is limited up and down, which is the result of a resonance due to the fact that the wind is on the side of the bridge at a rate consistent with the frequency of self-invism of the bridge。
On 26 april 2020, just 10 days before the tiger-gate bridge shivering, the body of the wuhan parrot river bridge was also wave-like and visible. Subsequently, in the design unit of the iron bridge survey and design institute, the nautilus river bridge was identified as a suspension bridge and the shaking was normal. The bridge maintenance unit also indicated that the motor bridge had an abnormal vibration caused by a particular wind condition and that the amplitude was within the scope of the design; the bridge structure was functioning and safe。
In addition, the hangzhou bay bridge, the canoe bridge, etc. Have all been shaken by typhoons。
Indeed, throughout the history of bridges, the phenomenon of tremors persists. Depending on the characteristics of the basic stress, the bridge can be divided into four main types of bridge: the liang bridge, the arch bridge, the ramp bridge and the suspense bridge, all of which have amplitudes, except that the beam bridge and the arch bridge have smaller amplitudes, which are not easily felt, and the wider slant and suspense bridge are more likely to produce “diverses” that are felt。
Carmon turbo street phenomenon. Mapkop china network
Why is the building shaking? It's mainly a resonance
In fact, the problem of shaking houses and bridges has long existed。
The collapse of the tacoma strait suspension bridge in 1940 in washington, d. C., brought the issue of building shaking to the for the first time. Under the influence of wind, the tacoma bridge was rocked and collapsed. This incident led to a major study by scientists of the problem of building shakes, which resulted in a significant development of the building's anti-vibration design。
According to existing research, the buildings were shaken, mainly by resonance. Resonance means the vibration of one object, which drives the vibration of another object. The closer the frequency of the vibrations, the greater the vibrations generated by the resonance. The source of resonance is generally wind or ground-based. Among these, ground-based forces are derived from a variety of factors, including earthquakes, ground-based deformations and surrounding construction operations. The above-mentioned shaking of the shenzhen yuzhmorgeologiya building was the result of ground-based deformation. In the case of bridge vibrations such as the tacoma bridge, this was caused by wind force。
In all cases of building shaking, wind-induced shaking is more common. The relatively long shape of the super-high buildings and bridges themselves makes both types of buildings vulnerable to wind swings. When vortex is present in the air, complex and volatile wind forces can easily lead to structural distortions. For example, the “camen turbo street” phenomenon refers to vortexes that occur when the wind bypasses a bridge or a high building, which in turn produces cyclical vortex and wind power. When the vortex cycle and the built-in cycle are closer, the resonance phenomenon leads to greater swings in buildings as the wind changes。
Corresponding standards for permissible vibrations are set in high-level building design codes and bridge design codes. Only if the vibration exceeds the permissible scope of the norm does it imply that the quality of the building or the environment in which it is situated is in question. This requires attention to be paid by the design, maintenance and maintenance sectors to mitigate abnormal vibrations in buildings and to prevent damage to human life and property。
Wind blocker for the 101st building in taipei. The building has a large steel ball with a weight of 660 tons on the 88-92 floors, which is used to slow the swing of the building. Maps on the news
How to mitigate the vibration of the building? This is the dictator
What are the ways to mitigate the vibration of the building
For vibrations resulting from wind force effects, special disturbance strips can be installed around buildings to disrupt the formation of vortex, thus avoiding the resonance of wind power. It would also be possible to install the aforementioned “trainers” in the building to absorb the energy generated by wind and ground-based forces, to avoid a resonance that would cause the building to expand the amplitude and mitigate the damage to the building。
Many of the world's famous super-high buildings have been equipped with blockers of some different types. For example, in some countries there are multiple earthquakes and more seismic effects are taken into account in the design of a barrier. Many typhoons in shanghai are designed to be more wind-resistant, so they are also called wind-trainers。
The country's first major wind-retarder, installed in the 101st building in taipei, was the largest wind-retarder in the world, weighing 660 tons and 5. 5 metres in diameter。
On the other hand, there are only two skyscrapers in shanghai, located in the high-rise forest: the shanghai central building and the worldwide financial centre. The introduction of electric vortex-tale-trainers in the shanghai central building for the first time in a wide variety of global types is also an innovative technology in my country. In simple terms, the wind functions mechanically on buildings, which eventually translates into thermal dissipation, through a resistance system。
The shanghai hye-eye building, located in the centre of shanghai, is beneath it a 1,000-ton blocker. Maps on the news
According to data provided by shanghai construction workers on the construction side of the shanghai centre building, such a barrier could reduce the wind peak acceleration by more than 43 per cent and allow 90 per cent of the building to feel greater comfort. On the 125th floor of the shanghai central building, this was visible. There's also an art device on the top of the blocker, called the shanghai hye-eye。
So, does the superstructure have to be wired? According to the experts, super-high-level wind resistance relies primarily on building structures and external design, and the role of the barrier is more like “bringing up” to reduce swings, optimize experience and improve the quality of the building, on the one hand, and increase structural durability, on the other. In accordance with the relevant national regulations, there is no compulsory installation of a barrier in the building。
While shaking does not necessarily mean that the building has a quality problem, it is important that, when the building does appear to have a visible shaking, it leaves the building as soon as possible, travel to a safe area and report to the relevant department for processing in a timely manner。
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