Rock Anchors

Rock anchors resist forces by means of corrosion protected steel bars embedded into bedrock. Geotechnical structures need anchors to counteract the uplift and other forces acting on foundations. The threaded bar is bonded to the bedrock socket wall or virgin soil by using high-strength grout (cement mixture).

After the anchors are constructed, the free-lengths are then post-tensioned, but bolts are grouted the full length of the bar and cannot be post-tensioned.

Rock anchors and bolts can have very high load capacities. Rembco has installed many different sizes. The largest could hold up to 1,000 kips.


Anchors:
Secure caisson bottom against uplift
Stabilize slopes and walls
Provide tiebacks for bridges
Increase stability of dams
Tension load tests

Bolts:
Secure surfaces in mines
Holds buildings against lift
Stabilization of steep slopes
Bases for guy line toggles 

Installation Sequence
 
1. Casing is advanced as hole is drilled with downhole hammer.

2. The drill pipe is removed leaving the steel casing sitting at bottom of socket.

3. Threaded tension bar lowered into the rock socket.

4. Grout pumped into the socket to bond walls to rock anchors.

5. The casing is lifted to mouth of rock socket to allow bonding.

6. Plates installed on top of epoxy coated bars for loading the tendon.

7. Anchor post-tensioned (prestressed) and locked off to maintain load design.
 

Drilling in Caisson Bottom © 1998 - 2008 Rembco Geotechnical