seismic for steel platform/canopy

[calvin21]

Similar to thread507-408840 question here - Designing a steel platform for some electrical equipments on top and made of WF beams and 4 WF columns on the corners. What would non building structure type from Table 15.4-2 be applicable? I am thinking All other self-supporting structures, tanks, or vessels not covered
above or by reference standards that are not similar to buildings

 

[driftLimiter]

If its similar to steel frame construction I would use a moment frame system or braced frame system. Your structure sounds pretty similar to a building to me.

The 'not similar to buildings' category is for things like tanks, vessels, equipment skids, etc.

If you have a steel framed elevated platform with steel beams and columns, it sounds an awful lot like abuilding.

You could use OMF and knee braces as indicated in AISC 341. This is a common approach for these types of structures.

A diagram of your structure would be useful.

 

[HTURKAK]

I would look section;
15.3 NONBUILDING STRUCTURES SUPPORTED BY OTHER STRUCTURES

What is 'some electrical equipments'? Could the wt of equipment be Less Than 25% Combined Weight Condition ?
A sketch would he helpful.



He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[calvin21]

Actually, yes this be Chapter 12 (not 15). This is seismic design category D with a pretty heavy equipment weight approx 60 psf so 15psf per column (less than 20psf). So a steel ordinary cantilever column is what am thinking.

 

[driftLimiter]

Cantilever column is a poor seismic system. You will be penalized severely in the R factor and the omega factor being applied to the foundation.

Recommend OMF system.