d. Pour the concrete mixture (one part cement, one part washed sand, and two parts crushed
stone or clean gravel) into the anchor hole to form around the anchor rod and square washer. Pour
enough concrete to fill about 25 inches (63.50 cm) at the bottom of the anchor hole. Tamp the concrete.
After the concrete has set, backfill and tamp the anchor and anchor rod holes.
13.
Installation of permafrost anchors.
a. Determine the ground location of the proposed guy. Apply heat (steam jet or hot water) to
thaw out the frozen soil where the anchor rod will be placed. A jet of live steam is preferred.
b. Bore a hole in the thawed earth for the anchor rod. Bore this hole in line with the proposed
guy. Place a nut, square washer, and another nut on the end of the anchor rod, in that order. Tighten the
nuts to prevent the washer from slipping. Position the anchor rod in the anchor rod hole.
c. Backfill and tamp the hole with moist unfrozen soil. When the backfill freezes, it should
hold the anchor rod securely in place. Do not apply the load to the anchor rod until the rod has been
frozen in place for at least 24 hours.
d. Test permafrost anchors for their required holding strength before the final load is applied.
14.
Installation of expanding rock anchors.
a. Determine the ground location for the proposed guy. Drill a 2-inch (5.08 cm) hole, 12 inches
(30.48 cm) deep, for the anchor. Drill this hole in line with the proposed guy. Where the solid rock is
below the ground surface, remove soil down to the rock surface before drilling. In this case, it will
probably be necessary to use a longer anchor rod.
b. Assemble the rock anchor and the anchor rod.
c. Lower the anchor rod and rock anchor into the anchor hole (Figure 2-22). Place a metal bar
through the eye of the anchor rod and use it as a wrench to turn the anchor rod until the anchor is firmly
expanded into the sides of the drilled hole. Backfill the anchor hole.
d. In rock, drill the anchor hole so the anchor will form a 90-degree angle with the proposed
guy. The eye of the anchor rod should not extend more than 1 inch (2.54 cm) above the rock. In soft or
shattered rock, it may be necessary to pour concrete into the anchor hole to prevent the rock from
crumbling when the load is applied to the anchor. The holding power of the anchor should be tested
with a pole jack before the final load is applied.
SS0439
2-24
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