PROFIS ENGINEERING
Table 33. Interaction
Tri-Linear: N ua ϕN n
+ V ua ϕV n
≤ 1.2
0.57 + 0.742 = 1.31 > 1.2 NO
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.
( 0.57) 5 / 3 +( 0.742) 5 / 3 = 0.392 + 0.608 = 1.0 = 1.0 OK FASTENING MEETS THE DESIGN CRITERIA IF PARABOLIC EQUATION USED.
SUMMARY Shear Load Acts Towards the y- Edge
• Shear load acting towards y- edge: consider concrete breakout for anchor rows 1, 2 and 3.
• PROFIS Engineering considers a maximum of three anchor rows with respect to shear concrete breakout calculations.
• Shear load acts eccentric( in the-x direction) with respect to the centroid of the anchor group.
• Shear load creates a torsion moment on the anchorage.
• Calculate resultant shear load( V ua, res) and check vs. concrete breakout strength( ϕV cbg)
• Assume V ua, res 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 row 1 and row 2 is less than c a1, row 1
• ACI 318 Case 3 provisions are relevant for row 1 and row 2.
• Calculate concrete breakout( ϕV cbg) from row 1 using c a1, row 1.
• Assume 1.0V ua, res acts on row 1( conservative assumption) neglects load on row 3
• Check ϕV cbg, row 1 vs. 1.0V ua, res
• y direction anchor spacing in between row 2 and row 3 is greater than c a1, row 1
• ACI 318 Case 1 / Case 2 provisions are relevant for row 1 and row 3.
• Calculate concrete breakout( ϕV cbg) from row 3 using c a1, row 3.
• Calculate concrete breakout( ϕV cbg) from row 1 using c a1, row 1.
• Assume V ua, res is distributed between row 1 and row 3
• Check ϕV cbg, row 3 vs. 1.0V ua, res
• Check ϕV cbg, row 1 vs. 0.5V ua, res
Shear Load Acts Towards the x- Edge
• Shear load acting towards x- edge: consider concrete breakout for anchor columns 1, 2 and 3.
• PROFIS Engineering considers a maximum of three anchor columns with respect to shear concrete breakout calculations.
• Shear load acts eccentric( in the + y direction) with respect to the centroid of the anchor group.
• Shear load creates a torsion moment on the anchorage.
• Calculate resultant shear load( V ua, res) and check vs. concrete breakout strength( ϕV cbg)
• Assume V ua, res acts towards the x- edge.
• y direction anchor spacing in each column is less than 3c a1, col 1
• Anchors in each column act as a group.
• x direction anchor spacing in between col 1, col 2 and col 3 is less than c a1, col 1
• ACI 318 Case 3 provisions are relevant for col 1, col 2 and col 3.
• Calculate concrete breakout( ϕV cbg) from col 1 using c a1, col 1.
• Assume 1.0V ua, res acts on col 1
• Failure surfaces for col 2 and col 3 merge with the failure surface for col 1
• Check ϕV cbg, col 1 vs. 1.0V ua, res
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