Alternative Support Systems for Cantilever - National Transportation ...

testing, signifying that the predicted behavior was likely correct. The modified concrete breakout
equations for torsion (See Equations 3-5 and 3-6) were proven accurate as the predicted failure
load with these equations was less than 1% disparate from the tested failure load.
The results imply that the embedded pipe and plate configuration in torsion alone would be
an adequate alternative to the current anchor bolt system. The torsional strength of the alternative
is greater than the anchor bolt system and can be accurately predicted using the modified
concrete breakout equations for torsion.
6.1.2 Torsion and Flexure Test
The implication of the torsion and flexure test is that the alternative selected, the embedded
pipe with torsion and flexure plates, is a suitable alternative to the current design using anchor
bolts. A comparison of the experimental test values and the calculated equivalent strength of an
anchor bolt setup show that the experimental test strength in flexure is approximately twice that
of the equivalent anchor bolt system (See design calculations in Appendix B). A large bulge of
concrete on the bottom of the shaft signifies a concrete breakout of the embedded flexure plate,
verifying the breakout was the failure mode. The modified concrete breakout equations for
flexure (See Equations 3-8 and 3-9) were proven accurate as the predicted failure load with these
equations was less than 1% off from the tested failure load.
These results imply that the tested system with the embedded pipe and torsion and flexure
plates is a viable alternative to the current anchor bolt system. The failure can be predicted
accurately using both the torsion and flexure plates and can easily be quantified using the
modified concrete breakout equations.
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