Design guide for considering concrete breakout in shear using ACI 318 anchoring-to-concrete provisions October 2025 | Page 18

PROFIS ENGINEERING
Shear Load Acting at a Corner
Figure 4.4.
Reference
Figure 4.4 [ 18 ]. It illustrates a hypothetical anchorage consisting of sixteen anchors which are unequally spaced with respect to both the x direction( s x12 ≠ s x23 ≠ s x34) and the y direction( s y12 ≠ s y23 ≠ s y34). There are two fixed edges which create a corner condition: one fixed in the x- direction( c a2, x) and one fixed in the y- direction( c a2, y). The shear load V ua acts at an angle towards the corner. The component of V ua that acts towards the x- edge is denoted V ua, x and the component of V ua that acts towards the y- edge is denoted V ua, y. Assume all anchors resist shear. Shear concrete breakout must be considered with respect to the following conditions:
• Shear concrete breakout occurs at the x- edge via the anchors in col 1, 2, 3 or 4.
• V ua, x, col n acts towards the x- edge
• MAX {( V ua, x col n / ϕV cbg col n)} controls with respect to shear towards the x- edge
• Reference Corner – Concrete Breakout Towards x- Edge( page 19)
• Shear concrete breakout occurs at the y- edge via the anchors in row 1, 2, 3 or 4.
• V ua, y, row n acts towards the y- edge
• MAX {( V ua, y row n / ϕV cbg row n)} controls with respect to shear towards the y- edge
• Reference Corner – Concrete Breakout Towards y- Edge( page 22)
• Shear concrete breakout occurs parallel to the x- edge via the anchors in col 1, 2, 3 or 4.
• MAX {( V ua, y col n / ϕV cbg col n)} controls with respect to shear parallel to the x- edge
• Reference Corner – Concrete Breakout Parallel to x- Edge( page 24)
• Shear concrete breakout occurs parallel to the y- edge via the anchors in row 1, 2, 3 or 4.
• MAX {( V ua, x row n / ϕV cbg row n)} controls with respect to shear parallel to the y- edge
• Reference Corner – Concrete Breakout Parallel to y- Edge( page 27)
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