PROFIS ENGINEERING
Figure 5.3e. Figure 5.3f.
Figure
5.3e [ 45 ] illustrates what can be termed an“ irregular” or“ non-matrix” anchor layout consisting of thirteen anchors in a circular pattern that do not align to form either a row or a column. Assume each anchor is located at a different distance from the x- edge; therefore, no two anchors are aligned to form a column( green dashed lines) with respect to the x- edge. Similarly, assume each anchor is located at a different distance from the y- edge; therefore, no two anchors are aligned to form a row( yellow dashed lines) with respect to the y- edge. When no anchors are aligned to form at least one row and / or one column, the band width approach is applicable.
Reference Figure 5.3f [ 45 ]. If shear concrete breakout was being considered for the x- edge, the band width with respect to this edge( green shaded rectangle) would be defined as:
band width in x direction =( 0.25)( distance in x direction between anchor 4 and anchor 11).
Band Width Approach – Concrete Breakout Towards the x- Edge( page 41) explains how band width calculations can be used when considering shear concrete breakout with respect to the x direction.
If shear concrete breakout was being considered for the y- edge, the band width with respect to this edge( yellow shaded rectangle) would be defined as:
band width in y direction =( 0.25)( distance in y direction between anchor 1 and anchor 8).
Band
Width Approach – Concrete Breakout Towards the y- Edge( page 40) explains how band width calculations can be used when considering shear concrete breakout with respect to the y direction.
Shear Load Evaluation
ACI 318 provisions for shear concrete breakout require the design concrete breakout strength( ϕV cb( g)) to be checked versus a factored shear load( V ua). ACI 318 Provisions for Shear Acting on Multiple Rows or Columns( page 2) through Considering Shear Concrete Breakout for Irregular Anchor Layouts( page 34) explain how ϕV cb( g) can be calculated for various design conditions. Shear Load Evaluation( page 45) explains how V ua can be calculated for various design conditions.
Shear Load – One Load Direction – One Fixed Edge( page 47) explains design parameters when shear load acts towards one edge.
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