On the afternoon of May 18, a sudden shaking of the building of Seg Building, a 79-story landmark building in Huaqiangbei, Shenzhen triggered heated discussions on issues related to the safety and stability of super-high-rise buildings.
damper fault? Concrete defects?
Civil Engineer Analyze the reasons for the shaking of high-rise buildings
Public information shows that the Seg Building , which was completed in 1999, is one of the earliest ultra-high-rise buildings in my country. It is 355.8 meters high, with a total building layer of 79 floors, 75 floors above ground, and 4 floors underground. It has a total construction area of 170,000 square meters. It is a landmark building in Huaqiangbei, Shenzhen.
After this incident, experts from relevant units and scientific research institutions formed the preliminary investigation results of the vibration of the Seg Plaza building. After analysis by experts from Guangdong Province and cities, it was initially believed that: First, Shenzhen Seg Building trembles up and down rather than swing left and right; second, the reason for tremors is that coupled is a variety of factors, mainly due to the influence of wind, as well as the subway operation (two subways pass by downstairs) and the influence of temperature (the temperature has increased in the past two days, with a temperature difference of 8 degrees, which has a great impact on the steel structure); third, after experts on-site inspection and consultation, the main structure of Seg Building is safe, the internal structure is solid, and various ancillary facilities are intact. The above investigation results are preliminary conclusions, and the specific reasons are still to be further investigated by the expert group.
A civil engineering industry insider analyzed the following four possibilities to the media about the reasons for high-rise buildings:
1. If the building has a damper, or the damper fails, it cannot effectively offset the shaking caused by the wind. However, it is not yet certain whether the building has dampers;
Dampers installed in , Taipei 101 Building. According to theconstructor.org
, the overall stiffness of the structure changes. If there are other construction work nearby, the foundation of Seg Building may be disturbed;
Third, Seg Building adopts a steel pipe concrete structure. This structure has some obvious disadvantages, and concrete needs to be injected into relatively small steel pipes. If the operation is improper or the inspection is not timely, defects in the core concrete in the steel pipe will appear, mainly manifested as holes, detachment and honeycombs. The occurrence of these defects will also lead to changes in overall structural stiffness;
4 is similar to the shaking of of the Humen Bridge last year, and the building resonates with the trend.
The industry insider said that high-rise buildings are generally shaking. He gave an example, for example, New York World Trade Center , when it is windy in spring, it usually shakes and deviates from the center by 15 cm to 30 cm. Under the action of a strong hurricane, the displacement can reach 1 meter, and the design is 1.2 meters according to the maximum wind force.
What is the point of fighting against the swaying of a tall building? Damper! Are there all skyscrapers in
?
When a tall building sways, the damper often plays a huge role.
The design director of a large state-owned construction company introduced that many high-rise buildings in China currently use dampers to reduce the impact of possible shaking on the people in the building. Shanghai Center made a 1000-ton damper and placed it on the top floor.
Wu Wei, assistant director of the technical R&D department of Shandong Regional Management Headquarters of Greenland Group, told media reporters that the movement of super-high-rise buildings mainly comes from seismic loads and wind loads.
UAE Dubai Sailing Hotel Damper Installation Location. According to theconstructor.org
But in fact, as for the current domestic super high-rise buildings, the wind force that can basically withstand is about level 13, which means that the general wind force has little impact on the main building of super high-rise buildings. Wu Wei introduced: "The reason why strong winds do not cause devastating damage to the building is because super-high-rise buildings generally undergo earthquake vibration tables and wind tunnels to simulate the effects of earthquakes and wind. There will also be several lines of defense when designing the building later."
"Take Jinan's tallest building - Jinan Greenland Puli Center as an example. Wu Wei said that although the building does not have a tuning mass damper, it has two lines of defense itself, and the design has added many strengthening measures. Therefore, it can basically ensure that there is no problem with strong winds once in 50 years, and strong winds once in a century may have temporary discomfort, but there is no problem with safety.
Tuning mass damper
. Regarding the damper problem mentioned above, Wu Wei said: "In some older super-high-rise buildings, tuned mass dampers will indeed be added, such as Taipei 101 Building. In layman's terms, it is to add some very high-quality or very large balls to the building, and reduce the energy through space shaking. But at present, in Shandong, super-high-rise buildings can solve this problem by relying on their own resistance. Due to frequent earthquakes, typhoons and hurricanes in southern regions such as Taiwan and Shenzhen, some additional measures may be needed to add to the buildings."
In addition, regarding the shaking problem of Shenzhen Seg Building, Wu Wei believes that it may also be the reason for the resonance .
How to maintain the stability of Qingdao "No. 1 High"?
is equipped with the world's first liquid damper with irregular water tank
Anti-strong wind is an inevitable topic for super high-rise buildings, especially Qingdao is windy in summer. What method is used to eliminate the impact of wind on the project? It is reported that in order to try to eliminate the impact of wind on the project, the project team benchmarked and went around the world. They first visited Shanghai Global Financial Center and Shanghai Center, and then flew to Canada for specialized damper tests.
Finally, combined with the layout and functions of the Haitian Center building itself, a passive tuning liquid damper was set up on the top of the T2 tower, which is the world's first liquid damper for irregular water tanks. The reciprocating movement of the waves in the water tank generates the inertia force of , which achieves the purpose of energy absorption and vibration reduction. Even under high wind conditions, it can still effectively ensure the safety and stability of the building and meet the highest requirements for comfort of future residents.
super high-rise building is shaking. Is
a quality issue or a normal imagination?
Now, high-rise buildings are not limited to commercial buildings, many residential projects are also designed as super high-rise buildings. Therefore, many netizens raised questions: Regarding the shaking of high-rise buildings, how to tell whether it is the quality problem of the building, or the normal shaking caused by strong wind?
netizens asked questions: How to distinguish whether
is a building quality problem or a normal phenomenon?
Wu Wei introduced: "In the construction industry specifications, the lowest bottom line is to ensure quality and safety, so the quality and safety of most buildings are guaranteed. Generally, it is required that the maximum acceleration calculated for the downwind and transverse wind directions of the building structure vertices should not exceed 0.25m/s². But people are very sensitive. If the acceleration reaches 0.1m/s² to 0.15m/s², people will feel uncomfortable. Therefore, when designing buildings, the problem of human comfort must also be considered. In this way, the building is additionally added to meet people's requirements for comfort."
Those high-rise buildings that once "swayed" in the wind
In recent years, earthquakes and typhoons are the main reasons.
During the "Mangosteen" typhoon in September 2018, many buildings in Shenzhen and Hong Kong shaking. The "Mangosteen" typhoon has the greatest impact on Shenzhen in 35 years. Its maximum wind speed when landing is level 14 (45 meters/second).
Affected by typhoon , the tallest building in Shenzhen, Ping An Financial Center also shook. "According to monitoring data, the swing of the tower top does not exceed 30 cm (one-sided), less than 50% of the design value." Yao Weijun, director of engineering management of Ping An Real Estate Shenzhen Branch, once said in an interview with the media, "The wind resistance of Ping An Financial Center is designed to deal with typhoons that occur once in 100 years, and can also deal with typhoons with an average wind speed of 60 meters/second and a maximum gust of 80 meters/second. In this simulation scenario, the calculated swing of the tower top (600 meters position) is 67 cm."
During the Mangosteen Typhoon, the buildings in Hong Kong Sunrise Kangcheng Community were also blown away. Sunrise Kangcheng is located on the beach of Tseung Kwan O, Hong Kong, with the height of the community floors at about 50 floors.
Residential buildings shaking in the Sunrise Kangcheng Community in Hong Kong during the Mangosteen Typhoon.
It is also reported that during the typhoon " Fanyabi " in September 2010, Taipei 101 shaking.
In addition to typhoons, earthquakes are also a major reason for the shaking of high-rise buildings.On April 20, 2015, when a magnitude 6.3 earthquake occurred offshore in eastern Hualien, Taiwan, the damper in Building 101 also shook.
On March 11, 2011, when a magnitude 9 earthquake occurred in the Pacific Ocean in northeastern Japan, many Japanese netizens took pictures of the shaking of tall buildings.
Japan earthquake when high buildings sway (the animation image has accelerated, but it actually sways slower)
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