Ductile Multiple‐Anchor Steel‐to‐Concrete Connections

Abstract

Multiple‐anchor connections are commonly used in attaching steel members to concrete. A typical connection includes a steel attachment, the anchors that actually do the connecting, and an embedment of the anchors into the concrete. The behavior and design of these connections is not well‐defined by existing design standards. Multiple‐anchor connections can be divided into two categories, connections for which strength is controlled by the strength of the anchor‐steel, and connections for which strength is controlled by the strength of the embedment. Based on experimental research, the behavior and design of connections for which strength is controlled by the strength of the anchor steel is addressed. A behavioral model for determining the distribution of loads to the individual anchors in a connection is presented. The model is based on limit design theory. Experimental results are reported for 28 tests of multiple‐anchor connections loaded monotonically by various combinations of moment and shear. Test specimens included steel attachments with rigid and flexible base plates connected to concrete with threaded cast‐in‐place or retrofit (undercut and adhesive) anchors.