Abstract
Steel and precast columns are commonly designed to transfer moment loads to concrete foundations through cast-in-place headed anchors. In design office practice in the United States, connection strength has been evaluated considering mechanisms emphasizing joint shear, strut-and-tie modeling, and anchoring to concrete. For any given connection, the strengths calculated with these three methods can differ by a wide margin. The application of these methods, including possible enhancements that improve strength estimates, is described. Laboratory tests were performed to provide benchmark physical data to determine the applicability of various design methods. The test specimens consisted of full-scale interior steel-column-to-concrete-foundation connections located away from foundation edges, with details typical of current construction practice on the West Coast of the United States. Strength in both tests was governed by concrete breakout failure. Strategically placed reinforcement increased the strength and displacement capacity of anchored connections governed by breakout. Design recommendations are provided.
Original language | English (US) |
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Pages (from-to) | 95-110 |
Number of pages | 16 |
Journal | ACI Structural Journal |
Volume | 119 |
Issue number | 5 |
DOIs | |
State | Published - Sep 2022 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors express their gratitude to the ACI Foundation Concrete Research Council, AISC, and Hilti Corporation for financing this and other ongoing research projects at UC Berkeley relating to concrete anchorage. Special thanks to R. Klemencic, Chairman and CEO of Magnusson Klemencic Associates; Level 10 Construction; Cascade Steel; and PJ's Rebar, Inc., for donations of materials and manual labor. This study was greatly improved through discussions with the following individuals: R. Sabelli (Director of Seismic Design at Walter P Moore), J. Malley (Senior Principal of Degenkolb Engineers), and Dr. R. Piccinin (Vice President for Code Development and Research at Hilti Corporation).
Publisher Copyright:
Copyright © 2022, American Concrete Institute.
Keywords
- anchoring to concrete
- beam-column joint
- breakout
- column-foundation connections
- shear reinforcement
- strut-and-tie
- supplementary reinforcement