We structural engineers here at Simpson Strong-Tie have a love/hate relationship with anchorage to concrete. Ever since the introduction of the strength design provisions in the 2000 IBC and ACI 318 Appendix D, anchorage to concrete has been a challenge for designers, building officials and manufacturers. SEAONC’s recent testing and the resulting code changes offer some relief to wood-frame designers for sill-plate anchor design at the edge of concrete, but many challenges remain.
With the increasing demand for high-density housing and urban infill projects, designers are now faced with anchoring multi-story wood-framed shear walls to relatively thin elevated concrete slabs (typically referred to as podium slabs). Overturning tension anchorage forces at the ends of shear walls in these projects can routinely be in the 40 kip range and even get as high as 60 kips or more.