Remember back to the days when you used allowable stress design for designing anchorage to concrete? Once you had your design loads, selecting an anchor was quick and easy. The 1997 UBC covered the anchorage to concrete in less than two pages, so the calculation was painless. Post-installed anchors were even easier, since allowable loads were tabulated and you just needed to apply a couple of edge distance and spacing reductions.
Since the introduction of strength design provisions and the adoption of ACI 318 Appendix D, first in the 2000 IBC, designing code-compliant anchorage to concrete has become much more complex. At least once (and probably not more) armed with a pencil, calculator, and an eraser, most of us have set out to design a ‘simple’ anchorage to concrete connection using the Appendix D provisions. Several pages of calculations later (and hopefully with a solution to the problem), most of us, I imagine, came to realize that designing anchorages to concrete by hand required much more time and effort than we anticipated or could allocate time for. As a result, many of us probably created an Excel template to speed up the design process using built-in functions and some Visual Basic programming.
The question is: are you still using the template?
For me, the answer is an emphatic “NO”, mainly because the spreadsheet I created has limited capability given the complexity in adapting the design methodology to complex anchor layouts, changes to the design provisions with each new code edition, and the need to add/modify data each time a new post-installed anchor product is introduced.
Fortunately for engineers, some anchor manufacturers like Simpson Strong-Tie have developed free design software like our new Anchor Designer software. The goal of the software is to assist engineers and designers in designing anchorages in concrete quickly, efficiently and with confidence, while providing comprehensive calculations conforming to ACI 318 Appendix D (and also Canadian Standard Association A23.3 Annex D, European Technical Approval Guideline, ETAG 001 and European Organisation for Technical Approvals, EOTA Technical Report TR029) using up-to-date data for code compliant anchor products. It’s a tool with an easy-to-understand 3D graphics user interface (which certainly looks far better than my Excel template). If you haven’t downloaded a copy of the software yet at www.strongtie.com/software, I would recommend it to help save you time and effort.
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