Self Drilling Bolt
ACARP – Roadway Development
11, 13, 21 September 2007
Sandvik – Global leader
Three business areas
Sandvik Tooling
Sandvik
Mining and Construction
Sandvik
Materials Technology
Invoiced
sales, SEK M
22,500
25,000
19,300
Employees
15,100
12,200
8,600
31 Dec. 2006
Sandvik February 2007
Sandvik
Mining and Construction
page 11
Introduction to Bolting
 The principal objective in the
design of a roof support
system is to help the rock
mass create a selfsupporting structure. The
usage of rock bolts can be
combined with wire mesh,
shotcrete and concrete lining
to cope with different
situations encountered
during mining or tunneling.
Sandvik Mining and Construction
Examples of Self Drilling Bolts
?
Hilti
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Sandvik
others
Problems with Current Rib Bolting Practise
 Need to drill hole and then retract, hoping the hole does not
collapse, install bolt and actuate to tension.
 Possible need to auger hole.
 Ability to reach rib with head plate.
 Safety ( Time spent on operation ).
 Potential for rib collapse.
 Manual handling.
 Mesh alignment.
 Number of consumables.
Sandvik Mining and Construction
Introduction to the SDB Bolting Concept
Sandvik Self Drilling Bolt (SDB)
 The objective – To develop a Self Drilling
Bolt for UG Soft Rock applications.
 The project started in Q4/2004 in MGT
Newcastle.
 Use hollow bar to allow flushing during
drilling.
 Mechanical anchoring and post grouting (if
needed).
 Drill, Tension and Grout.
Sandvik Mining and Construction
Development Cycle Simulation
MINING SYSTEM PERFORMANCE
TYPICAL COLLIERY
12
8
6
TWO HEADING
PANEL LAYOUT
4
Distance Shunt - Face
Length of Pillar
METRES per OPERATING HOUR
10
ABM2020
ABM-
Shunt (S1)
Shuttle Car
2
Shunt (S1)
Distance Shunt to Boot
Overdrive
Shuttle Car
Boot-end
Boot-end
Width of Pi ller
4 roof bolt, 2 rib bolt, mesh, 2 S/C only, 14t cars
0
10
30
50
70
90
110
130
DISTANCE FROM SHUNT S1 (m)
ABM without SDB
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ABM with SDB
CM withot SDB
CM with SDB
Technical Advantages
 Self Drilling- Installation of the bolt is quicker and simpler when
it drills it’s own hole.
 Strength- axial load capability (stiffness) is increased through
the combined use of a mechanical anchor plus full encapsulation
with either thixotropic or cementatious grout.
 Pretension- as the bolt is pre-tensioned by use of the
mechanical anchor, the rib layers are forced together before the
injection of the grout. Standard chemical capsules can be forced
into cracks and fissures under the hydraulic pressure created
when the bolt is inserted which results in separations being held
open and a loss in encapsulation.
Sandvik Mining and Construction
Rib Bolt Data Sheet
Bolt Description
 Hollow bar OD = 19mm, ID = 9.5mm
 Frazer & Jones D10L Expansion Shell
 Nut (M20 LH) with shear pin, 36AF (optional non-shear pin for no
tail bolt)
 Bolt length: typically 1.2m (any length can be supplied)
 Plate: Special SDB Butterfly Assembly
Plain Hollow Bar




Tensile Strength (kN)
Yield Strength (kN)
Standard Elongation (50mm) (%)
Bar Shear Strength (kN)
Sandvik Mining and Construction
Typical
140
110
23-38
90
Installation Procedure
 Insert self drilling rib bolt in
drill chuck.
 Drill 36mm diameter hole in rib
using SD Bolt & RH rotation on
rig.
 On completion of drilling,
anchor bolt by using reverse
rotation on drill motor to set
expansion shell and tension
bolt.
Sandvik Mining and Construction
Animation
Sandvik Mining and Construction
Trials to Date
 Drill trials at Mandalong, West Wallsend and
Beltana
 trialling steel drill bit design
 Bolt trials at West Wallsend and Mannering
 trialling old style self drilling bolt
 SD Bolt trials at Mandalong
 current design and trials
Sandvik Mining and Construction
Pull Test – D10L Anchor in Coal
 West Wallsend - 10, 10, 12, 8, 13, 13, 12.5, 9.5,
9.5, 16 tonne
 Mannering - 16 tonne
click on photo to play
pull test video
Sandvik Mining and Construction
Grouting Recommendations/Options
 Rib bolt has threaded hollow centre bar allowing
easy coupling of grout pump and straight clear
grouting passage through centre of tube.
 Initial contacts with Specialist Site Services, with
regards to post grouting the SD Bolt, have indicated
no foreseeable problems.
 Currently organising trials with BASF, developing
grout and resin compositions.
 Grout trial with solid bolt design proved feasibility of
grouting, and new hollow bolt design should better
suit grouting.
Sandvik Mining and Construction
Engineering Changes to Miner/Drill Rig
DRILL RIG:
 Triple stage bolting rig.
 SDB chuck, extension dolly.
 Reverse rotation controls.
 Pressure control on reverse
rotation (95 bar = 200Nm on
ME10).
Sandvik Mining and Construction
Hazard Study & Risk Assessment
 A Hazard Study and Risk Assessment for the Installation
Procedure of the Sandvik Self Drilling Rib Bolt, has been
developed in conjunction with Mandalong Colliery.
 Also a pull test SOP has been done. ( West Wallsend,
Mandalong Colliery ).
 Could use these documents as templates for your colliery.
 Will conduct a separate study to your requirements if needed.
Sandvik Mining and Construction
Customer Implementation Process
 Step 1 – Customer request, initial presentation and meeting
 Record feedback and interest
 Step 2 – UG survey of equipment and current practise
 View and measure continuous miner, drill rigs and clearances,
understand the engineering issues of what will impact on the
installation procedure
 Step 3 – Final proposal presentation to mine
 Fully engineered and costed proposal back to mine
Sandvik Mining and Construction
Value Proposition for Customers and Sandvik
Customer:

Improved safety – operator is exposed 50% less time, reducing risk.

Improved productivity – drivage rates will improve due to time savings.

Reduced bolting costs – bolting cycle time is reduced lower total costs.

Ability to automate – use of only one consumable, eases automation task
compared with current three consumable practise (rod, sausage and bolt).

More choices and competition.

Improved maintenance outcomes – halves movements on drill rig.
Sandvik:

New opportunity in more stable consumable business.

Sandvik seen as a solution provider for rapid roadway and mine development.

Increased customer process focus.
Sandvik Mining and Construction
Future Developments
 Roof SD Bolt.
 Cuttable Rib SD Bolt.
 Continue to develop bolt.
 Future automation.
 Total system solution.
Sandvik Mining and Construction