PROFIS ENGINEERING
Figure 5.3d.
Figure
5.3d [ 44 ] illustrates what can be termed a“ regular” or“ matrix” anchor layout consisting of eight anchors that are aligned in a circular pattern to form rows and columns. Assume anchor 2 and anchor 4 are aligned to form a column; anchor 1 and anchor 5 are aligned to form a column; anchor 8 and anchor 6 are aligned to form a column. Similarly, assume anchor 2 and anchor 8 are aligned to form a row; anchor 3 and anchor 7 are aligned to form a row; anchor 4 and anchor 6 are aligned to form a row. When two or more anchors are aligned to form a row and / or a column, the band width approach is not applicable. Instead, ACI 318 shear concrete breakout provisions can be used directly, i. e. consideration of Case 1 / Case 2 and / or Case 3 for the rows and columns that make up the anchorage.
If shear concrete breakout was being considered for the x- edge, anchor 3 would be treated as a“ column”( col 1) consisting of one anchor. Likewise, anchor 7 would be treated as a“ column”( col 5) consisting of one anchor. Anchors 2 and 4 would constitute a column( col 2), anchors 1 and 5 would constitute a column( col 3), and anchors 8 and 6 would constitute a column( col 4). Case 1 / Case 2 and / or Case 3 for each column would be predicated on the spacing in the x direction between columns. Shear concrete breakout strength for each column( ϕV cb( g), col n) would be checked versus the shear load assumed to act on each column( V ua, x, col n).
If shear concrete breakout was being considered for the y- edge, anchor 1 would be treated as a“ row”( row 1) consisting of one anchor. Likewise, anchor 5 would be treated as a“ row”( row 5) consisting of one anchor. Anchors 2 and 8 would constitute a row( row 2), anchors 3 and 7 would constitute a row( row 3), and anchors 4 and 6 would constitute a row( row 4). Case 1 / Case 2 and / or Case 3 for each row would be predicated on the spacing in the y direction between rows. Shear concrete breakout strength for each row( ϕV cb( g), row n) would be checked versus the shear load assumed to act on each row( V ua, y, row n).
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