news

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

just as "capricorn" was tearing off the roofs of houses in hainan, "bebejia" was rummaging through the boxes in the yangtze river delta.

this year's 13th typhoonbebeccathe center of "" landed in lingang new town, pudong, shanghai, around 7:30 on the 16th, becoming the strongest typhoon to land in shanghai since 1949. the typhoon installed on the 125th floor of the shanghai towerthe thousand-ton "smart eye" damper began to shake, the swing amplitude is about more than 1 meter.

the damper started working｜shangguan news

during the previous typhoon, some people filmed a video of a building shaking in the wind, which made many netizens shout "scared"! some even thought that thisthe building's foundation has problems, it is a "shoddy construction".some netizens simply don't believe that the building will be shaken by the wind.to be frank, it’s “p”!

when a typhoon hits,does the building really shake? is everything really okay? what is the purpose of the thousand-ton damper?

skyscrapers:

not only during typhoons and earthquakes, but also during normal times.

when skyscrapers encounter typhoons and earthquakes, they are subjected to changing wind loads (i.e. the force exerted by wind on the structure) and ground vibrations, which will produce reciprocating dynamic deformation, which is what everyone feels as "shaking". the vibration of structures is unavoidable and is the inevitable reaction of structures under dynamic action.in fact, buildings do vibrate under normal circumstances, but the amplitude of the vibration is very small and it is difficult for people to notice it.under strong loads such as typhoons and earthquakes, the vibration amplitude of the building increases accordingly. in addition, skyscrapers also need to "shake" toconsumes a large amount of energy input from typhoons and earthquakes。

visible,there is no scientific basis for judging a building as a "shoddy construction" simply because it shakes during a typhoon.。

before the construction of a building begins, engineers will conduct structural design. based on the building's location, engineers will estimate the earthquake and typhoon effects that the building may be subjected to, and make corresponding designs to minimize the building's structural response under these external loads (i.e., the general term for all external environmental forces on the structure).in coastal areas with strong winds, wind loads are often the controlling factor in structural design, so engineers often usewind-resistant design.wind-resistant design must meet the design requirements of structural strength, stiffness, comfort, fatigue resistance, etc., to ensure that the structure will not collapse, crack, or displace excessively under wind loads, thereby ensuring the safety of the structure.

you may wonder why you can’t feel the shaking when you are in a building during a typhoon?

in fact, the main factors affecting human comfort are vibration frequency, vibration acceleration and vibration duration. the vibration duration mainly depends on the wind action time, and the vibration frequency of the structure is difficult to adjust.therefore, in structural design, the method of limiting structural vibration acceleration is generally adopted to make people feel more comfortable.

degree	annoying	very troubled	unbearable
limit	15gal	50gal	150gal

human body vibration comfort control limit＊1 gal = 1/100 m /s^2.

when the vibration acceleration of a building reaches 0.15 m/s^2, people inside it will feel the building shaking.

damper:the wind doesn't move, i don't move

the wind blows south, i blow north

if we only rely on the deformation of the structure to resist the effects of typhoons and earthquakes, a lot of cost will be needed to improve the performance of the building itself during the construction process, which will inevitably lead to waste of materials.

at this time,a device that can absorb or consume the energy brought by typhoons and earthquakes and reduce structural vibrations——damperit's on stage.

dampers can generally be divided into two types:one is an energy dissipation damper and the other is a tuned damper。

energy dissipation damper

from the energy point of view, the energy input into the building by a typhoon or earthquake is constant.the more energy the energy dissipation device dissipates, the less energy the structure itself needs to dissipate.energy dissipation damperthis principle is used to reduce the vibration of buildings.

the petronas twin towers in kuala lumpur, malaysia, uses energy-dissipating dampers.empty bridge between two buildingsto balance the shaking between buildings, energy-absorbing dampers are installed at the connection points between the sky bridge and the buildings. under the action of earthquakes or typhoons, they will first enter the inelastic state, consume a large amount of earthquake energy, and thus reduce the vibration of the structure.

petronas twin towers, kuala lumpur, malaysia

tuned dampers

tuned dampers transfer the energy of a building to the substructure by adding a substructure.these substructures often weigh hundreds of tons, and when a typhoon or earthquake shakes the building to one side, the dampers also move, with their inertial motion in the opposite direction of the building's motion.

according to the different substructures, it can be divided intotuned mass damper(tuned mass damper, referred to asTMD)andtuned liquid dampers(tuned liquid damper, tld for short).

becausetuned mass damperit has the advantages of good vibration control effect on high-rise building structures, little impact on building functions, low cost, small footprint, and easy installation, maintenance and replacement. it has been widely used in actual high-rise building structure wind vibration control projects.

figure | tuned mass damper

1. shanghai tower

the thousand-ton "eye" of the shanghai tower is an eddy current tuned mass damper., is an innovative technology in my country. it is currently the heaviest damper in the world, accounting for about 0.118% of the building's weight. it is suspended inside the building by 12 25-meter-long steel cables, and the maximum unilateral swing is 2 meters. when strong winds hit, this giant compound pendulum will swing in the direction of the wind, and use its own swing to reduce the swaying amplitude of the building.

photo: shanghai tower

2. shenzhen ping an financial center

during typhoon mangkhut, shenzhen ping an financial center, as the tallest building in shenzhen, was able to remain intact under the strong typhoon, mainly becausetwo tuned mass dampers installed insideabsorbs a lot of energy through inertial motionthe two dampers weigh 500 tons each and are placed on the 114th floor of the building.the damping ball can swing up to 2 meters in strong winds.。

3. taipei 101

the taipei 101 building, built in 2004, has a 662-ton wind damping ball installed between the 87th and 91st floors. eight steel cables weighing up to 20 tons are wrapped around the bottom of the ball, connecting the damping ball to the main structure. below the damping ball, there are eight horizontal and eight diagonal viscoelastic dampers. the wind damping ball is one of the main structures for the building to resist wind and earthquakes.in 2013, typhoon soulik, the damping ball produces inertial motion,swing range up to 70 cmthe damper absorbs a large amount of vibration energy brought by the typhoon, greatly reducing the swing of taipei 101 in strong typhoons.

the arrangement of tuned mass dampers in taipei 101

the damping ball weighs 662 tons

in the face of strong winds and earthquakes, dampers are likelike a magic needleits existence not only protects the safety of the building, but also gives people peace of mind.