Friday, April 25, 2008

Re: Vibration Problem

Swami,

It is hard to make any suggestions based on the information given.

The vibrations may propagate due to various reasons, and any decision
about mitigation activities should be made after a series of tests
that would include measuring the vibrations at various operating modes
of the compressor.
I would recommend bringing a dynamics professional on site to consult with.

For example, last year we investigated the 300MWt steam turbine
vibrations. The cause was a large horisontal crack in the concrete
foundation bottom below ground level, which was then grouted by
injection.

Do you have any image of the structure to post?

Regards, Alex.

On 4/25/08, Swami Raviraj (Mumbai - Civil) <R.Swami@ticb.com> wrote:
>
>
> In one of the process structure(in petroleum industries ) which is @ 60m high & plan dimensions 34 x 54m at bottom (with offset of 9 x 12m ) & reduced to 22x 20m(at top)
> It's RCC up to first level & steel above it.
> It's already erected at site (Operating condition)
> there is one big compressor at ground level (located at hardly 1 - 1.5m) from main structure.
> Two big pipes are coming from this compressors (900 dia) & entering in main structure at 25m level from ground level
> 3 supports are taken for pipe from main structure at intermediate levels.
>
> when we start this compressor the structure also starts vibrating (& its really much more like earthquake at 25m level)
>
> Now I have to check that why its happening & what are the remedial measures for it.
>
> So I need your suggestions for it
>
>
> Regards,
> Raviraj R. Swami
> Tecnimont ICB,
> Civil Dept.
> Mumbai-400064
>
>
>
>
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--
Alexander Bausk
CAD manager, Structural engineer at
Nuclear Engineering&Research Lab
Dnipropetrovsk, Ukraine

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