What are the hazards of using single inclined shims for tower equipment?
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It is well known that specifications require shims to be used in pairs. But what if there is slight deformation in large-diameter skirt seats? Should I adjust the skirt seat or the shims? What if three shims can be used to level it out, but it still does not meet the specifications? The key is whether safety and quality can be guaranteed; whether it violates regulations is another matter.
What kind of deformation is mild deformation? Is the cylinder’s roundness not up to standard? If the roundness requirement isn’t met, it definitely won’t work; the standards and the drawings both specify requirements in this regard. This component is designed to withstand bending moments (in other words, it’s under compression on the back side)
The diameter of the skirt base is 6.4 meters, and the levelness of its contact surface with the foundation exceeds the specified limits. How should this be addressed?
So the levelness of the skirt foundation ring plate is out of spec, right? This is then a problem related to construction quality. HG/T 20584 has regulations on this matter; in my opinion, efforts should start with the construction phase itself – problems should not be left until the installation stage, as this not only leads to disputes but also makes it impossible to ensure quality. See the screenshot for relevant regulations:
Yes, that’s right – the skirt foundation slab exceeds the specified limits. The equipment skirt has been manufactured and delivered to the construction site; it’s not feasible to send it back to the factory for repairs. Is there a solution on-site?
Uh, I’m sorry I can’t help; I’ve never encountered such a problem in practice. Sorry, I can’t help
The tower foundation shims need to be load-bearing, and inclined shim sets are used to level it. After the tower is installed, the main parameter is the verticality of the tower body; the levelness of the skirt foundation ring is not a key criterion for evaluation.
By saying that the horizontal level of the skirt foundation ring is out of spec, I mean its lower surface is not level with the surface in contact with the shims; this prevents a tight fit between the shims and the lower surface of the skirt. Can grouting still be carried out in such a situation?
For a diameter of this size, the requirement for flatness is 1.5 mm; to be honest, it’s difficult for manufacturers to meet this requirement. As long as it remains within the adjustment range of the shims, I think there should be no problem using it
This post was last edited by gcbllz on 2017-12-22 at 17:00. Are shims used to adjust the elevation? If the lower surface of the skirt is not level, and it is bent inward at the bottom and upward on the outside due to welding deformation, there will definitely be a gap between the shims and the lower surface of the skirt. How should this be dealt with?