The Self-Drilling Hollow Bar Anchor System is comprised of a hollow threaded bar with attached drill bit that performs drilling, anchoring and grouting in a single operation.
Below is the diagram of a typical model hollow drilling anchor rock bolt:
Product Code
R32N
Diameter
Steel Grade
Bar Type
Length
32
S460
SDA
3
Average Cross Section Area
430mm2
Ultimate Load
280KN
Yield Load
230KN
Average Tensile Strength
650MPa
Average Yield Strength
530MPa
Agt
5%
Bend Test
Following ASTM A615:
Bending around 180°
Nominal Weight
3.2Kg/m
Thread Standard
ISO 10208
Accessories examples for Self-Drilling Hollow Bar Anchor System
Drill Bits
Nut
Dome Plates
Coupler
Key Features
1. Drilling, anchor installation and grouting in single operation
2. Separated anchor installation or removal of casing and drill rods is not required
3. Similar installation methods for all ground conditions
4. Choice of drill bits for different ground conditions
5. Hollow core is used for flushing with air or water during drilling along with grouting the anchor tendon
6. Flexibility in length by using couplers
7. Ability to work with small drill rigs without casing in restricted headroom conditions
8. Enhanced corrosion protection available upon request
Standard Length & Packaging
Standard length available include 2.0m, 3.0m, 4.0m, 6.0m, 9.0m.
Standard bundles of 50, custom packaging available on request.
Installation
- Grouting
Normally afterwards
Manual installation:
Guiding – Gripping – Extending - Drill through - Grouting - Tensioning with nut
Semi-mechanized installation:
Guiding – Gripping – Extending - Drill through – Grouting via an injection adapter - Tensioning with nut
Simultaneously with drilling using a rotary injection adapter
Rotary Percussive Drilling:
High rates of installation, good directional stability.
Simultaneous Drilling and Grouting: suitable for granular soils and fills.