PROFIS ENGINEERING
Considering
Shear Concrete Breakout for Irregular Anchor Layouts
Figure 5.
Reference Figure 5 [ 34 ] above. It illustrates a hypothetical anchorage consisting of eight irregularly spaced anchors. A shear load( V ua) acts obliquely towards the x- and y- edges. None of the anchors aligns with respect to the x direction so as to form a row consisting of adjacent anchors located equidistant from the y- edge. Reference the yellow dashed lines. Likewise, none of the anchors aligns with respect to the y direction so as to form a column consisting of adjacent anchors located equidistant from the x- edge. Reference the green dashed lines.
If analyzing this anchorage for shear concrete breakout per ACI 318 provisions, the nominal concrete breakout strength for a single anchor( V cb, nn) would be calculated for any anchor considered to resist shear load. The spacing between each anchor in the assumed direction of the shear load( towards a fixed edge) and the distance of the anchor to that fixed edge are used to determine if Case 1 / Case 2 and / or Case 3 are relevant for calculating( V cb, nn) for a particular anchor. Extrapolating ACI 318 Shear Provisions for Irregular Anchor Layouts( page 35) discusses how ACI 318 provisions can be used to analyze irregular anchor layouts.
Band Width Approach for Irregular Anchor Layouts( page 38) discusses what will be referred to as the“ band width” approach to analyze shear concrete breakout for irregular anchor layouts.
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