Tilt up panel brace removal?

[mitch6]

We did the structural design of the tilt up wall panels for 2 story office building here in Raleigh, NC and are now being asked to verify that it is OK to take the temporary braces down. We did not design any of the temporary bracing, nor did we design any of the lifting inserts or methods to place the panels. The panels are all now connected to the main steel structure. Are there any rules of thumb for how long the braces need to remain in place? Should we be advising on when to remove braces? ACI 551.1 states that the engineer designing the lifting inserts typically also designs the temporary panel bracing. There doesn't appear to have been an engineer who did this design, as we did not get a submittal.

Any insight into this is appreciated!

Thanks,

Mitch Fluhrer, PE
Fluhrer Reed, PA

 

[civilperson]

If the main steel structure has ALL of its bracing components, then the tilt up panels can use the building as a source of lateral support. The steel deck roof may have been designed as a diaphragm so check that the roof joists/deck and bridging is complete.

 

[msquared48]

Temporary bracing is the responsibility of the contractor and/or lifting insert design engineer in this case. Defer it to the other engineer. Don't budge on this one.

FYI, I would assume that the location of the bracing had nothing to do with your results in the panel reinforcing size or placement.

Mike McCann
McCann Engineering

 

[mitch6]

Yes, we designed the panels in their completed form to be braced by the roof and floor diaphragms, and those are not in place yet so I had to answer that we could not sign off on the removal of any braces until the diaphragms were substantially complete. Thanks for your reply.

Mitch Fluhrer, PE
Fluhrer Reed, PA