ASCE 7 Load Combination(s) to Include Mechanical Vibration

[Illbay]

I'm trying to design a structural frame for a piece of vibrating equipment. This is the first time that I've encountered dynamic loading outside of seismic (which has its own very well-defined and quite elaborate rules) that potentially govern the design, and it's not clear how to handle it. I note that the very first entry in the list of loads in ASCE 7-16 Section 2.2 is "A-sub-k" which is defined as "load or effect arising from extraordinary even A", which would seem to suit my purpose exactly. Except there is no load combination where "A-sub-k" appears in either section 2.3 or 2.4. The commentary is utterly silent on the subject. So how do you properly account for this load effect in combination with others?

"No one is completely useless. He can always serve as a bad example." --My Dad ca. 1975

 

[phamENG]

The live load chapter has factors for "impact loads." This includes elevators and machinery (both light motor driven and reciprocating). So if you have a reciprocating machine that weighs 1000lbs, you apply a 1000lb dead load and a 500lb live load. This should be increased if required by the manufacturer. You may also need to apply it laterally depending on the orientation of the equipment.

The combination you reference there is if somebody drives a truck into a column of your frame and you don't want it to collapse (or some other "extraordinary" event).

 

[GC_Hopi]

If you are design a steel frame make sure you consider serviceability and vibration concerns and not just strength. Steel frames are susceptible because you can end up with something quite light ie low mass.