Undercut anchors are an ideal post-installed anchor category as their load transfer mechanism is bearing, similar to that of headed studs cast into concrete. Their mechanical interlock prevents the anchor from pulling out and results in high load capacities and small displacements. They can be designed such that with sufficient embedment depth and other design features, undercut anchors have high strength, stiffness, and ductility levels. The design of undercut anchors can also qualify them for ductile connections in seismic design. Their general robustness makes undercut anchors the preferred choice for critical connections where high load demands are to be transferred into the concrete safely.
Undercut Anchors for Structural Applications
Philipp Mahrenholtz, Ph.D., Mark Ziegler, P.E. and Derrick Watkins, Ph.D., S.E.
Structure Magazine, April 2022