Supports satisfying seismic analysis

Hi Friends,
For seismic analysis we have to provide Y support at many locations.
1. could any one please tell me how we can practically design these support.
2. we have to provide guids with no gap also to get the analysis pass. But how we physically provide a support which allow only linear movement and arrest vertical and side wise movement.

I believe many of our forum members will have answer for this... pls drop in. msibym@gmail.com

Plese visit the Anvil site:


http://www.anvilintl.com/Literature/Catalogs.aspx

download the following catalog:

Pipe Hangers and Hardware Catalog (including Engineered Hangers)

Take a look at page 133. You may find some answers.

Regards,

Thanks dan. really helpful link.
I have more queries.. Y supports needed at most of the locations for passing seismic cases. but is it required to provide that much rigid supports in practical cases. I can't digest it(0gap in + & - direction for vertical and guide supports)

...SM

Frankly speaking, no, I don't think. A 2..3 mm gap is normal. There are indeed some cases where 0 gap is required (e.g. sensitive equipments), but not everywhere. For calculation purposes (i.e . in order to have system convergence in Caesar) you can use 0 gap, and to have real 2...3 in site.

Search on this forum and you will find more opinions and information regarding this subject.

Regards,

But do CAESAR explains in this regard, am not finding any thing in search for the assumptions in seismic cases and the practical deviations allowed.
And hence for me, I have to provide shoe support at all points to arrest the vertical up movement, other wise I was able to manage with an economical wear pad.

more expert opinions please..

...SM

What "g" load did you inserted in your calculation?

Siby,

You might be looking for support design details that CAESARII does not have the specifics.

A 'Y' restraint that might be considered for small size piping could be a simple U-bolt to the structural steel. This is not easy if the structure support is concrete beam. An imbedded plate is needed then for U-bolt.

Small size piping on a rod hanger can be made to a 'Y' restraint with a steel angle or channel shape fastened to the rod hanger with U-bolts to stiffen the rod hanger. Another steel angle or channel shape in the horizontal/lateral direction could restrain the lateral direction to act as a guide. Some designs use steel cables to restrain the lateral movement of a rod hanger. If the pipe sizes are too large for a U-bolt, then a 'box' of steel angle or channel shapes could restrain vertical and lateral movement.

The pipe shoes are not necessary. If there is insulation on pipe, then installation of the pipe shoes would make sense.

One more thing, review the way you construct your load cases.

Regards,