PROFIS ENGINEERING
Table 11. Interaction
Tri-Linear: N ua ϕN n
+ V ua ϕV n
≤ 1.2
0.174 + 0.941 = 1.12 < 1.2 OK
Parabolic: N 5 5
ua 3 V ua + 3 ≤ 1. 0 ϕN n ϕV n
ACI 318-19 Eq.( 17.8.3)
Reference ACI 318-19 commentary R17.8.
( 0.174) 5 / 3 +( 0.941) 5 / 3 = 0.054 + 0.904 = 0.958 < 1.0 OK FASTENING MEETS THE DESIGN CRITERIA.
SUMMARY
• Consider shear concrete breakout for anchor rows 1, 2 and 3.
• PROFIS Engineering considers a maximum of three anchor rows / columns with respect to shear concrete breakout calculations.
• Assume shear load acts towards the y- edge.
• x direction anchor spacing in each row is less than 3c a1, row 1
• Anchors in each row act as a group.
• y direction anchor spacing in between each row is greater than c a1, row 1
• ACI 318 Case 1 / Case 2 provisions are relevant.
• Calculate concrete breakout towards y- edge from row 1, row 2 and row 3
• Calculate ϕV cbg, row 1 using c a1, row 1 and check vs. 0.33V ua
• Calculate ϕV cbg, row 2 using c a1, row 2 and check vs. 0.67V ua
• Calculate ϕV cbg, row 3 using c a1, row 3 and check vs. 1.0V ua
•( 1.0V ua / ϕV cbg, row 3) controls the design with respect to concrete breakout in shear
•( 1.0V ua / ϕV cbg, row 3) controls the design with respect to all shear failure modes
•( N ua / ϕN cbg) controls the design with respect to all tension failure modes
• Tension / shear interaction is satisfied: fastening satisfies ACI 318-19 provisions.
For more information on extrapolating ACI 318 shear concrete breakout provisions with respect to this design example, reference Equal Number of Anchors and Equal Spacing – Case 1 / Case 2( page 7) in the design guide.
One Fixed Edge- V ua Towards Edge- Case 3
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