Sam_Eng
Structural
- Feb 25, 2022
- 3
I am designing a seismic retrofit for a 110,000 square foot tilt-up building that was designed and constructed in 2000-2001 to the 1997 UBC. The building retrofit is to be designed as a risk Category IV building (essential facility) per the current code (2018 IBC) to the extent that it can be. The problem I am currently encountering is that Hilti KB-IIs were used to connect the tilt up walls to steel angle ledgers connected to the metal roof diaphragm and anchor the walls to the roof diaphragm as well. KB-IIs are not approved for use in cracked concrete and all concrete should be assumed to be cracked when in a high seismic zone (seismic design zone D).
I have contacted Hilti and they were not all that helpful, giving me an old catalog section for calculating the allowable load on the anchors, and suggested that I do some in place testing of the anchors. I'm not sure what the testing would accomplish as the concrete is likely not cracked and the anchors will likely test out to the 2x the allowable anchor load.
I can't imagine this is the first time something like this has happened. Does anyone here have any references on using non-complying anchors for current codes?
I have contacted Hilti and they were not all that helpful, giving me an old catalog section for calculating the allowable load on the anchors, and suggested that I do some in place testing of the anchors. I'm not sure what the testing would accomplish as the concrete is likely not cracked and the anchors will likely test out to the 2x the allowable anchor load.
I can't imagine this is the first time something like this has happened. Does anyone here have any references on using non-complying anchors for current codes?
