1. Drilling up to design mark
1.1. Anchors are to be installed by successive drilling of rods into the ground. The rods that make up the tie rod are built up using couplings while drilling. The first rod must be equipped with a drill bit.
1.2. Anchor rods are to be fed into the ground at a constant speed of not more than 0.5 m/min. and rotation about 50 rpm. For a drilling fluid is to be used a cement grout with a water-cement ratio W:C=1.0 (flushing), flushing pressure 0.5-1.5 MPa.
1.3. For water-cement grout is to be used portland cement of a grade not lower than PC400, GOST 10178-58 *.
1.4. Water used for preparation of the grout must meet the requirements of GOST 23732-79 and does not contain impurities that cause metal corrosion and prevent cement setting and hardening.
1.5. While drilling, it is necessary to monitor the filling of the well with flushing cement grout. Drilling is to be carried out only when there is output of drilling fluid and drilling cuttings out of the wellhead. When the fluid output stops, it is necessary to reduce the feed rate of the drill rods or to stop the feed of drilling rods without stopping rotation. After the drilling fluid output has resumed, it is necessary to resume the feeding of the rods.
1.6. Drilling of the rods and tightening of the couplings is to be carried out with the use of drilling rig and manual feeding of the rods.
1.7. For testing and fixing the structure, it is necessary to keep the last rod output from the wellhead.
2.1. After the calculated depth is reached while rotating of the drilling rod, a thick cement slurry with W: C = 0.4 is to be injected and displace the drill cuttings and insure the anchor ground bearing capacity.
2.2. The break between drilling and pressure testing should not exceed one hour, otherwise the drilling cuttings may thicken, it may not be completely displaced by a thick cement mortar from the wellhead and, accordingly, the solidity of the anchor body cement stone will be broken and the bearing capacity will decrease.
2.3. Injection of a thick cement slurry is to be carried out through the cavity of the rods and the drilling bit.
2.4. Well dynamic pressure testing is to be carried out with continuous rotation of the screw tie rod at a speed of 20-30 rpm, which ensures the rise of the cement slurry from the drill bit and its distribution without voids along the entire length of the embedment.
2.5. Pressure testing is to be carried out before the output of a thick cement slurry from the wellhead.
2.6. If there is no output of a thick cement slurry from the wellhead, it is necessary to repeat the pressure testing after 15-30 minutes through the hollow rod left in the well.
2.7. Consumption of cement mortar during dynamic pressure testing should be 50-60 liters per running meter of anchor depending on soils and bit diameter.
2.8. The drill rod is to be left in the well as an anchor tie rod.
3.1. Atlant ground anchors do not require pretensioning due to the high rigidity of the structure.
3.2. While installing the Atlant screw anchor mounting point it is enough to tighten the nut with a wrench with a tightening torque of 40-50 kgf-m.
3.3. Fastening, as well as testing of Atlant screw anchors, is to be carried out after curing of cement stone. The appropriate period is determined according to the composition of the cement slurry. The recommended period is 28 days.