Effect of Abandoned Holes on Capacity of Wedge Bolts

Seventy, 5/8-in. diameter wedge anchors were tested in direct pull-out to determine the effect of various configurations of unused holes and different treatments of these holes on pull-out capacity. The test results indicated that for unused holes as close as approximately 2.0 bolt diameters, there was a measurable reduction in pull-out strength. When the holes were as far away as 3.0 bolt diameters, there was no reduction in capacity. When holes as close as 1.5 bolt diameters were filled with drypack mortar, the anchors behaved as if there were no additional holes present. Thus, no reduction in pull-out load, even the extreme case of holes 1.5 bolt diameters away from an anchor, need be considered when the holes are filled with dry-pack mortar.