Our preferred method for anchors/tiebacks is an all threaded hollow bar. The Self-Drilling Hollow Bar Anchor System is comprised of a hollow threaded bar with an attached drill bit that performs drilling, anchoring and grouting in a single operation. The hollow bar allows air and water to freely pass through the bar during drilling to remove debris and then allow grout to be injected immediately after drilling is completed. Grout fills the hollow bar and completely covers the entire bolt. Couplers can be used to join hollow bars and extend the bolt length while nuts and plates are used to provide the required tension. The Self-Drilling Hollow Bars are known for
their excellent load capacity and are available in Normal (N) and Special (S) types with diameters from 1 to 4 in. (25 to 103 mm).
Hollow Bar Anchor System Advantages:
Drilling, anchor installation and grouting in single operation
Separate anchor installation or removal of casing and drill rods is not required
Similar installation methods for all ground conditions
Choice of drill bits for different ground conditions
Hollow core is used for flushing with air or water during drilling along with grouting the anchor tendon
Flexibility in length by using coupler
Ability to work with small drill rigs without casing in restricted headroom conditions
Enhanced corrosion protection available upon request.