Engineerataltitude
Structural
- Oct 31, 2008
- 83
in the 2022 CBC Sec 1905.1.8 ACI 318 Section 17.2.3, section 17.10.5.3 (d) requires the seismic overstrength factor for wood framed shear walls, 3.0, to be applied to the net uplift load at wood framed shear wall ends. When combined with all the ACI limitations on concrete breakout and adhesive strength (Simpson SET-3G), I can't find any adhesive anchors to retrofit into an 8" concrete stem wall that will work with any of the Simpson Strong Tie holddowns.
CA modified ACI 318 to allow sill anchors to still work without that overstrength factor and all the brutal edge distance limitations. But that exception seems specific to sill anchors.
Am I missing something in the codes (exceptions, etc.) that will allow me to get out of having to use that overstrength factor on the holddown load? Otherwise I can't figure out how to retrofit holddowns into existing concrete stem walls. Is that the code intent?
SFR project in snow country in SCD D. Light frame construction.
See attached standard retrofit detail, I've used for years. I was just about to updated it with SST new HDUE and SET-3G epoxy.
CA modified ACI 318 to allow sill anchors to still work without that overstrength factor and all the brutal edge distance limitations. But that exception seems specific to sill anchors.
Am I missing something in the codes (exceptions, etc.) that will allow me to get out of having to use that overstrength factor on the holddown load? Otherwise I can't figure out how to retrofit holddowns into existing concrete stem walls. Is that the code intent?
SFR project in snow country in SCD D. Light frame construction.
See attached standard retrofit detail, I've used for years. I was just about to updated it with SST new HDUE and SET-3G epoxy.
