Deflection Limits for Platform Column

[HiggsBoston]

I am currently designing a relatively high (11m) access platform that comprises of a walkway at 8m and a monorail at the very top. Given the height of the columns, the top has a tendency to sway in wind causing service deflections of about 69m on top. Since the structure does not have any cladding elements, I was wondering if l/150 is a reasonable deflection limit to avoid installing extra braces to the structure. Please see the attached image below.

 

[phamENG]

I'm guessing you meant 69mm, not 69m. I guess it depends. Will the monorail need to be used when it's windy? If so, you need to find out what the allowable sway for monorail operations are. Either technical limitations from the manufacturer, or safety limitations from the facility - whichever is more restrictive.

 

[Retrograde]

Typical values I have seen are h/250 for smaller cranes and h/300 for cranes with SWL > 10t