The tower is shaking a lot, how to solve it?
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A few days ago, during winds of force 8, a tower with a diameter of Φ2400 and a height of 60 meters shook violently; the top of the tower swung by at least 1 meter, and the reboiler at the base of the tower moved along with it. The adjacent towers, however, didn’t show much movement, which was quite worrying. The foundation bolts were found to be in good condition, and a theodolite was used to check the verticality, which also seemed fine. Some people say it might be due to resonance – what could be causing this?
The problem is a row of towers, and only his appears to have the greatest degree of movement
The actual wind resistance does not match what was taken into account during design. Find equipment manufacturing and equipment design
1. Vibration of tall towers is a complex issue; researchers interested in this topic can consult the standards related to chimneys and towers. 2. Due to the complexity of the calculation process, as well as the many parameters for which constants must be selected based on specific conditions, designers need to have certain experience. 3. The general aspects of tower vibration are explained through case studies. 3.1. Tall towers vibrate when subjected to lateral wind forces, and there is a critical wind speed at which such vibration occurs. When wind speeds exceed the lateral critical wind speed under certain meteorological conditions, the vortex shedding phenomenon occurs, resulting in significant swaying at the upper part of the tower. 3.2. The critical wind speed of a tower is related to its shape and structural dimensions; when the calculated critical wind speed is below a certain value, the likelihood of encountering high wind speeds in the area increases, necessitating measures such as installing windbreaks at the top of the structure. 3.3. When designing a tower, consideration is given to withstanding the extreme wind speeds based on meteorological statistics over its service life, such as those that occur once every 10 years, 30 years, or even 50 years. Therefore, generally speaking, the probability of vibrations that could cause damage to the tower is relatively low, though exceptions do exist – I have personally witnessed two instances of significant swaying in tall chimneys. 4. It is indeed problematic when such situations occur during the operation of the facility, as it is difficult to find reliable and effective solutions. Our solution involves adjusting the natural vibration frequency of the chimney based on the specific conditions of the equipment, thereby increasing the critical wind speed and reducing the likelihood that the actual wind speed will exceed this critical value, thus alleviating vibration.
According to NB/T47041, resonance occurs.
There must be something wrong with your tower; I happened to build a 2400 model tower that was 80 meters tall, and during a typhoon of level 12, measurements taken with a theodolite showed that the tower swayed by about 25 cm
Yesterday, there was a northwestern wind of force 9, and the reboiler supports and foundation were welded together; however, the wind speed was higher than before, yet the tower shook less. The last time there was shaking, it was an 8-level southwest wind, causing significant shaking.
Wind at level 12 – such a slight shaking!
Please take a look at the tower calculation sheet and check what the calculated value of the top deflection is. Such significant shaking could affect the functionality of the tower.