Design guide for considering concrete breakout in shear using ACI 318 anchoring-to-concrete provisions October 2025 | Page 129

PROFIS ENGINEERING

Interpreting

the Design Results

•( N ua / ϕN cbg) controls the design with respect to tension failure modes.

•( V ua, col 1 / ϕV cbg, col 1) controls the design with respect to shear failure modes.

• Tension / shear interaction is satisfied if parabolic equation is used.

• Fastening satisfies ACI 318-19 provisions.

• If calculated design strengths( ϕV cbg) were checked vs. V ua, x and V ua, y in lieu of V ua, res, shear parallel to the edge could also be considered:

•( 1.0V ua, x / 2.0ϕV cbg, row 1) assumes V ua, x acts parallel to y- edge only on row 1

•( 1.0V ua, y / 2.0ϕV cbg, col 1) assumes V ua, y acts parallel to x- edge only on col 1

For more information on extrapolating ACI 318 shear concrete breakout provisions with respect to this design example, reference Equal Number of Anchors and Unequal Spacing( page 10) in the design guide. For more information on calculating resultant shear load for an oblique load condition, reference Shear Load Evaluation – Oblique Load – Two Fixed Edges( page 51) in the design guide.

Two Fixed Edges- Shear Load Parallel to Both Edges – Case 1, 2 and 3

carbon steel: f ult = 58,000 psi f y = 36,000 psi

Sustained Tension: N ua = 6000 lb h ef = 8.0 in

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