Dynamic Behavior of Single and Double Near-Edge Anchors Loaded in Shear

Under the sponsorship of the U.S. Nuclear Regulatory Commission, a research project has recently been completed whose objective was to obtain technical information to determine how the seismic behavior and strength of anchors (cast-in-place [CIP], expansion, and undercut) and their supporting concrete differ from the static behavior. To that end, a research program was carried out on the dynamic behavior of anchors in concrete. The research program comprised four tasks: 1) static and dynamic behavior of single tensile anchors (250 tests); 2) static and dynamic behavior of multiple tensile anchors (179 tests); 3) static and dynamic behavior of near-edge anchors (150 tests); and 4) static and dynamic behavior of multiple-anchor connections (16 tests). The anchors tested were selected based on their reported frequency of use in nuclear power plants in the US. Anchors included cast-in-place headed bolts, grouted headed bolts, two wedge-type expansion anchors, one sleeve-type expansion anchor, and two undercut anchors. Loading conditions included tension, shear, and combined tension and shear. Test variables included different concrete types and strengths, loading rate, and the presence of cracks. In this paper, the dynamic response of single and double near-edge anchors loaded in shear is described.