Nowadays, towers are lifted as a whole; how should the disturbance caused by lifting be taken into account? Do I need to calculate it?
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I came across a post about the effects of deflection in towers and the hazards associated with excessive deflection. When the ratio of a tower’s height to its inner diameter is high and the wall thickness is thin, wind loads can cause excessive deflection at the top of the tower. In the case of sieve trays, excessive tilting of these trays leads to uneven liquid layers on them, resulting in uneven gas-liquid mass transfer and a decrease in the efficiency of the trays, which in turn affects product quality； 2. Excessive swaying of the tower causes additional tensile and bending forces at the flanges connecting to the tower body, resulting in leakage ； 3. When the length-to-diameter ratio of the tower is large, wind loads may induce resonance in the tower, leading to fatigue failure ； ----------------------------------------- Nowadays, towers are lifted as a whole; how should the disturbance caused by lifting be taken into account? Do I need to calculate it?
This post was last edited by The wise on 2021-12-2 09:11. These issues were taken into account during the design phase. During the design phase, the designer requires the contractor to provide information on possible transportation methods, installation methods (on-site assembly, multi-stage lifting, overall lifting, etc.), and potential cranes, so that enhancements such as reinforcement rings, support ribs, and lifting lugs can be taken into account during the design process.
The tower is basically lifted as a whole, unless there are transportation issues
If you observe carefully, for many projects carried out by Huajian, large-scale towers are basically lifted in sections.
Now it’s time to wear clothes and hats as well; before, the lifting capacity wasn’t sufficient
1. The hazards associated with excessive deflection of the tower refer to potential impacts during operation; the focus here is on the effects that occur during lifting, and there are 3 such hazards. It can be concluded that the deflection resulting from lifting will not cause any issues. 2. Large-scale lifting is subject to certain climate constraints, and safety is a key concern during this process; the factors involved include the strength of the tower structure, the lifting lugs, and the welds. During the initial stage of lifting, the process by which the tower changes from a horizontal to a vertical position inevitably results in some deflection. Within just a few dozen minutes, it is almost impossible for the metal material to yield; this means that such deflection is a form of elastic deformation, and it disappears once the tower becomes vertical. 3. In the design of tall and slender towers, both vibration resistance and wind resistance require that the tower have sufficient stiffness, as well as adequate strength to withstand internal pressures. These measures are sufficient to meet the stiffness requirements needed during lifting.
During the design of tall and slender towers, both vibration resistance and wind resistance require that the tower possess sufficient stiffness, while the ability to withstand internal pressures demands adequate strength; these measures are sufficient to meet the stiffness requirements of the tower for lifting purposes. ------------------------ Do you mean that this stiffness fully meets the requirements during lifting?» ? ?
1. In accordance with the standards for tower-type containers, the design process involves considering all critical sections; the effective thickness of each section is determined taking into account the requirements related to manufacturing, transportation, and installation, until all verification conditions are met. 2. The calculation software includes data on the mass of the tower during lifting, indicating that lifting considerations have been taken into account in the calculations
It’s still a question; I hope it doesn’t bother you: if lifting is possible, then why are multiple saddles needed during transportation and placement to prevent bending? ? ?
This post was last edited by lupg on 2021-12-2 at 21:08 :lol, it’s no trouble – let’s exchange ideas. 1. The tower has a circular cross-section; if it is manufactured in a factory, the platform and the pipelines attached to the tower may already be assembled. Even when the tower is in its bare form, the numerous manholes and connection flanges prevent it from being placed firmly on the ground. Therefore, saddle supports are installed at appropriate locations to ensure the tower can be positioned stably and to avoid stress caused by collisions between pipes. These supports also help to secure the tower during transportation. 2. Transportation involves prolonged periods of jolting, and severe shocks exert stress on the tower. This constitutes a “dynamic load” for the tower structure. While the weight of the tower remains constant, the loads resulting from these shocks need to be applied gradually at the start of lifting, as local stresses can be much higher in such cases. Observe that during road construction, impact tools can break up concrete roads, but static forces are not effective for this purpose. 3. Long-distance transportation takes much longer than the lifting time, and time is also a factor in this regard. Imagine an exaggerated movement of the human body: what is the difference between doing it occasionally versus doing it continuously over a long period of time? The same is true for metal objects. Do a push-up and give it a try.