Masonry Wall

[rfisenne]

I am reviewing plans for a new generator building and am a little concerned about the stability of the structure. The building is 40' x 24' by 10' high and built of concrete block. It has a scissor truss roofing system. The 24 foot walls are made up entirely of louvers for air intake so there is only a minimal (a 16" block return) to resist racking due to wind load on the 40' wall. There is no pilasters along the 40 foot wall and no steel moment frame to resist racking of the building. Anybody have any input about this? Other relevent info about the building..... IBC wind zone of 110mph. Block walls are reinforced with durowall every other course and has a horizontal reinforced bond beam every 4'. Do I need any more structural elements to resist racking in the 24' louver wall? Also cross bracing the 24' wall will not work due to the intake/exhaust ductwork for the generator.

 

[AlohaBob]

You definitely need a structural engineer. I would be glad to give you a referral.

 

[stellabella]

I would also look at how the lateral wind loads are transferred from the endwalls of the scissor truss framed roof. Are thee any lateral members transferring the loads through the bottom chords? Or, are the bottom chords just secured individually to the tops of the the block walls? In any case, if the 24'walls consist mostly of louvers, I doubt that this will provide the shear wall resistence required.

 

[AlohaBob]

I suspect that the piers are reinforced properly. Probably the stability of the system is good too. It's just with heavily reinforced masonry piers in shear, depending on the type of load, seismic or wind, the detailing and code peculiarities are significant.

It would be good to verify the existing plans.

 

[CSEllc]

I recommend you hire a local structural engineer.

Based on info I see several other potential issues. For example, the scissor trusses have a horizontal thrust at their base. How is this thrust resolved? If not properly resisted, the CMU wall might not be adequately braced.