Jennmar Queensland Cert IV Workplace Training and Assessment By John Naylor & By John Naylor & Harold Hinton Jennmar Queensland Correct Installation for.

Slides:



Advertisements
Similar presentations
Self Drilling Rock Bolt System for the Coal Industry Ground Support Services Pty Ltd & Alminco Pty Ltd March 2008.
Advertisements

ACARP Roadway Development Operators Workshops - October 2011
AUSTAR COAL MINE A2 MAINGATE ROADWAY DEVELOPMENT Experiences and Lessons Learned Presenter Glenn Sobey Development Mining Engineer Austar Coal Mine.
Present Procedure for cutting stuck casing on Drilling PLATFORM
Drills & Drilling Drills & Drilling.
Fundamentals of Cutting and Cutting-Tool Materials & Cutting Fluids Presented by: Rita Silvernail Tony Cordisco John Congdon Richard Gasbarra.
What is a fastener? A device to locate or hold parts
Drill Press and Hand Drills Team 2165 Docu-Mentor-y September 15, 2008.
Stadium Roof Design - S2 : Stadium Roof Design - Emirates Stadium Structural Analysis.
1Copyright © Xstrata plc Tensionable Tendons Phil Howes Tahmoor Colliery.
Self Drilling Rock Bolt Technology for the Coal Industry Advanced Solutions Ground Support Services Pty Ltd September 2007.
RESIN. RESIN CARTRIDGE RESIN COMPARTMENT ( 90% BY VOLUME ) UNSATURATED POLYESTER RESIN Polyester Backbone Promoters Inhibitors COURSE FILLER FINE FILLER.
Clarifying Cable Bolting Practices and Principles Mine Managers Association of Australia 2012 Annual Seminar 7 – 8 June 2012 Jim Galvin.
ACARP – Roadway Development 11, 13, 21 September 2007
Connection Design.
CM 197 Mechanics of Materials Chap 20: Connections
General idea of a couple of check rod system and adjustments
Drilling machine.
COLUMNS.
Soil and Rock Sampling. Environmental Site Characterization Number of samples taken depends on the size of the site Hollow stem auger normally used for.
Sawing. Reciprocating saws (power hack saw) being replaced by horiz band saws only cuts in one direction up to 24” x 24”
Slop Stabilization Pertemuan
Basic Structural Theory. BASIC STRUCTURAL THEORY TECHNICAL STANDARDS BRANCH INTRODUCTION TO BRIDGES TRANSPORTATION Slide 2 Beams Different member types.
FOOTINGS. FOOTINGS Introduction Footings are structural elements that transmit column or wall loads to the underlying soil below the structure. Footings.
PARKING BRAKE OPERATION, DIAGNOSIS, AND SERVICE
Gandhinagar Institute of Technology
Flat Saw Training. Flat Saw Sizes –Low Horsepower Blade diameters range from 8” (200mm) to 18” (450mm) Power ranges from 4 to 25 horsepower.
4.4 SOIL NAILING SOIL NAILING IS A REINFORCEMENT METHOD TO REINFORCE THE GROUND WITH STEEL BARS OR STEEL BARS IN GROUT FILLED HOLES. IT IS MAINLY USED.
1.5 AVERAGE SHEAR STRESS Shear stress is the stress component that act in the plane of the sectioned area. Consider a force F acting to the bar For rigid.
© 2009 GSS Pty Ltd 1 SDRB S YSTEM USING P UMPABLE R ESIN  Considerable improvements to the crawler rig  Development work on a new pumpable resin including.
Setting up correctly Different types and their use
Main Parts of a Drilling Machine
Drilling machine. Introduction Drilling is a metal cutting process carried out by a rotating cutting tool to make circular holes in solid materials. Tool.
Operational Theory of Compression Small Engines Ag. 221.
Foundation Failure. Foundation movement may result from a wide range of factors, which can include: Shrinking or swelling of clays caused by changes in.
ENM208 INTRODUCTION to MACHINING ANADOLU UNİVERSITY Industrial Engineering Department.
This presentation is for illustrative and general educational purposes only and is not intended to substitute for the official MSHA Investigation Report.
Fluid Mechanics for Chemical Engineers Arif Hussain (Lecturer)
Sentek Training Presentation © 2003 All rights reserved Sentek Pty Ltd Sentek Sensor Technologies Installation of EasyAG 50 and EasyAG 80.
Fundamentals of Metal cutting and Machining Processes THEORY OF METAL MACHINING Akhtar Husain Ref: Kalpakjian & Groover.
Technical Standards Branch Class B Bridge Inspection Course BIM Bridge Inspection and Maintenance Basic Structural Considerations INFRASTRUCTURE AND TRANSPORTATION.
"Improvements in the Bolting Cycle Using Conventional Installation Methods" John Naylor – Queensland Technical Manager, Jennmar Harold Hinton – Queensland.
Pocket Holes Coach Ketcham Productions.
UNIT-5. ELECTRICAL SAFETY, WIRING & INTRODUCTION TO POWER SYSTEM
DRILLING Dept. of Mech & Mfg. Engg..
How to make Buildings ductile for Good Seismic Performance?
Introduction Bridge members must be able to carry the loads applied to them. This presentation considers: how loads are applied to members how bridge.
Introduction: Excavations and other engineering constructions in the ground are central to many civil and mining projects. Ground reinforcement includes.
Auto Tow Conversion Course
Metalwork Threaded Fasteners.
Soldering Technique.
Tool removed during cycle Fault #2
Industrial Skills Fasteners & Hardware.
CALL/WHATSAPP
Facing & Center Drilling
2. Compression and Tension
MACH 112: Cutting Tools & Measurement
Contents Introduction Identification of the knowledge gap
Introduction to Pavement Design
Govt. Polytechnic,Manesar
Drilling machine.
Design Ribbed and Flat Slabs
Structure II Course Code: ARCH 209 Dr. Aeid A. Abdulrazeg
CONNECTION Prepared by : Shamilah
Mechanical Properties: 2
Drills & Drilling Drills & Drilling.
Correct Procedures for Changing, Storing, and Maintaining Saw Blades
BUILDING CONSTRUCTION
Presentation transcript:

Jennmar Queensland Cert IV Workplace Training and Assessment By John Naylor & By John Naylor & Harold Hinton Jennmar Queensland Correct Installation for a 1.8m roof bolt

Differing Strata

Stresses that can cause rock failure. Horizontal Stress – one direction usually much greater than the other Horizontal Stress Vertical Stress – Weight of overlaying rock Horizontal Stress – Tectonic plates are moving and pushing into one another

Horizontal Stress concentrates in the roof/floor Vertical Stress concentrates in the ribs STRESS CONCENTRATIONS AROUND THE DEVELOPMENT HEADING

Bit Geometry Is greatly dependant on the rock strata and the thrust capabilities of the rig. Twin Wing Bit - Positive Rake Twin Wing Bit - Negative Rake Modified Spade Full Spade Twin Wing Bit - Positive Rake Twin Wing Bit - Negative Rake Modified Spade Full Spade Rib Bit. Specially sharpened General Purpose Bit, featuring Good general bit features Strongest design of roof bit. for rapid drilling in coal. the good drilling the strength of blade Used for drilling in the for rapid drilling in coal. the good drilling the strength of blade Used for drilling in the Positive rake allows for easy characteristics of a two wing carbide with quicker hardest of roof conditions use with hand borers. bit with the toughness of drilling time than a With the most powerful use with hand borers. bit with the toughness of drilling time than a With the most powerful a negative rake standard spade drill rigs. a negative rake standard spade drill rigs. MOST AGGRESSIVE STYLE BIT LEAST AGGRESSIVE STYLE

1.8m Bolt and 1000mm F/S Resin Most mines in the Bowen basin use a 1.8m bolt in the roof as standard. Other sizes go from 1.5 – 2.4m bolts, with rib bolts going from 1.2 – 1.8m. Belt hanger and structure bolts vary in length from 0.6 – 1.8m. Resins range from 300mm single speed through to 1400mm DUAL speed (TOOSPEED) for every day mining. For today we will work with a Standard 1.8m bolt and a 1000mm Fast/Slow resin.

Drilling the Hole Drilling the Hole Drill Bit :- Usually 27 mm or 28, no larger Hole depth : mm shorter than bolt Flush the hole well with water Annular gap between the bolt and the bolt hole should be 4-6mm Hole drilled to correct depth & diameter will help to ensure oMaximum chemical encapsulation oMaximum load transfer oThread length available for tensioning Ensure correct rig alignment Incorrect drill rig alignment may cause the nut to break out early, bolt may not get to the back of the hole and resin may be under mixed. In some cases this may cause fractures in the threaded section of the bolt and may cause a bolt fail.

Drilling the Hole for 1.8m Bolt A experienced operator can tell while drilling the hole if there are substantial partings parting in the strata by watching the drill head and the speed of the bore hole being drilled mm is the ideal length hole for a 1.8m bolt, this leaves 100mm of tail for the roof plate, dome ball and nut leaving 50mm of tail for hanging equipment.

1000mm Resin Both common types of resin used in the underground coal mines in Australia have around the same spin and hold time on then, this is to minimise any confusion by the end user. There has been some questions lately about the 25 in the part code, this is a generic number. The calculated number should be 23.8mm for the diameter for the resin when doing encapsulation calc's.

Two-Speed Resin Operation  Two-speed resin operates by the fast-set (yellow ) going hard first and allowing the roof bolt to be put in tension by tightening the nut on the bolt.  The slow-set (blue) gels and sets 60 seconds later.  This system helps create the beam of support from the bottom of the fast set to the collar of the drilled hole.  This is the area of the roof which is placed in tension – by “pre-tensioning the bolt” Pre-tension

Inserting the Bolt Through the Resin Insert the resin capsule to the back (top) of the hole before commencing full rotation with enough thrust to get through the resin capsule in around 10-12sec. Care must be taken not to burst the capsule or push the bolt into the resin capsule before rotation has commenced, as this may cause gloving of the capsule Once at the back of the hole the bolt should be spun for another 2- 4seconds but no more than 5seconds as this may cause the resin to granulate -over mixing of the resin. A 1000mm resin in a 1700mm hole in solid competent ground will normally have a little excess resin come out from the collar of the bore hole indicating a full column of resin.

Resin Loss into Strata In some cases the fine silts, granules between the cleats (stacking layers) in the strata and some of the strata material itself can be flushed out when drilling the hole for the bolt which can lead to the bolt not being fully encapsulated. In some cases this has been as much as 50% of the bolt being un-encapsulated. When a section of bolt is not encapsulated with resin, this section is left exposed to corrosion with high alkaline (acidy) water, strata movement – leaving it more susceptible to shear as the strata has more of a chance for movement in this area of the borehole column as there is no fill between the bolt and strata. Resin Loss into Strata

How Roof Bolts Resist Ground Movement/ Resist Stresses

Effects that Poor Encapsulation has on the Beam Poor Encapsulation reduces Beam thickness Poor Encapsulation reduces Beam thickness Poor encapsulation exposes bolts to shear Poor encapsulation exposes bolts to shear Causes of Poor encapsulation : 1.Mixing through the chemical too fast 2. Over drilling 3. Undetected resin loss into fractures

Strata Compression–Beam Building It is important that after the correct hold time that the nuts on the bolts are tightened correctly. The bolt nut needs tightening until the drill motor stalls to reach the desired pretension for the mine. It is also important that the bolts are tensioned before the slow set resin cures and starts to go hard (60sec). If this happens the pre-tension area between the fast set resin and the bearing plate of the bolt will not be compressed as desired,and the strata will be left susceptible to movement in the area as the clamping would not have been achieved.

Tightening the Bolt Tightening the Bolt 1. Hold for a minimum of 12 seconds but no longer than 60 seconds. 2. Apply full rotation and tighten the nut / plate to the roof. Tighten until the rig stalls to achieve correct tension THE BOLT IS NOW COMPLETED HOLD TIME IS CRITICAL Beware when 1 operator is using 2 rigs that letting the resin set while using the other rig will often exceed 60 seconds cure time – This allows the slow resin to cure and the bolt tension is NOT compressing the bottom roof layers. Wait for the fast (top) resin to cure enough to carry the 6-8 tonnes pre-tension.

A Reinforced Beam can carry Stresses A Reinforced Beam can carry Stresses Encapsulated bolts resist ground movement axially & in shear Pre-tension clamps the layers together, increasing friction across bedding planes to help resist movement. The fuller the encapsulation, the stiffer the beam.

COMMON PROBLEMS

Incorrect Drilling

Correct Drilling

NUTS "Breaking out” early This is when the nut breaks out before correct mixing is completed. It can create gloving, unmixed resin and long tails. Causes- Resin “out of date” and heat effected resin (thickens &goes hard). Worn/broken drill bits /very hard bands of rock create a small hole Poor rig alignment with the hole e.g. bolt dragging on mesh Swelling / wet clay bands in the roof. Drill stops set in-correctly Nut breaks out when bolt hits back of hole

Chemical not mixed Bolt not adequately tensioned- in some cases (Plas/Resin-Nut) bolt may come off under load Load carrying reduced. No thread tail protruding Check to see if drill stops on drill mast are operating or missing. Over drilled Hole

Designed bolt horizon not reached Potential partings not supported Unable to adequately tighten bolt Under Drilled Hole

Bolt Tensioned “Too Soon”Bolt Tensioned “Too Soon” “Coat Hanger” Caused By:Caused By: Tensioning before fast set resin has curedTensioning before fast set resin has cured Hitting back of hole with boltHitting back of hole with bolt Broken strata-resin lossBroken strata-resin loss

Over Spun Bolt Chemical – “ground up”-check label on resin carton for spin time & set time Unable to take loading A “NON-BOLT” This bolt must be replaced [drill a new hole and start again.]

“Gloving” For a roof or rib bolt to work efficiently, there must be un-interrupted interaction between the strata, resin and the bolt For a roof or rib bolt to work efficiently, there must be un-interrupted interaction between the strata, resin and the bolt In this case, the un-shredded capsule (glove) has formed a barrier between resin and strata. “Gloving” is when the plastic resin capsule film is not shredded during installation. It can sit between the resin and the bolt or rock and stop bonding/anchoring of the bolt. CAUSES: 1.Pushing the bolt up into the capsule before starting to spin. 2.Pushing up too fast during mixing, 3.Rapid insertion with minimal spinning on the way up. 4. Not using full speed rotation.

Gloving -continued To avoid the gloving phenomenon, follow the points below, all of which are under the Operators control : The annular gap between the bolt and the bolt hole must not be too large (4-6 mm). This could be caused by a large hole –check drill tip size The bolt is spun through the entire length of the resin capsule. If the bolt is pushed (without spinning) through the resin capsule before rotation commences, some of the capsule skin may be pushed to the top of the hole without effective shredding, and gloving could occur. Ensure maximum drill speed during bolt installation. Ensure feed rate (thrust) of bolt into hole from machine is not excessive. This is also very important as high feed rates of the bolt through the DUAL SPEED (TOOSPEEDIE) resin (eg < 3 secs) has also been shown to reduce encapsulation. Ensure bolt rotation continues when bolt reaches back of hole for 2-3 seconds..

Jennmar Queensland As previously highlighted, resin bolts are spun and pushed simultaneously to the back of the hole during installation with maximum rpm to mix the resin components and to assist in shredding the capsule skin, to avoid gloving. As previously highlighted, resin bolts are spun and pushed simultaneously to the back of the hole during installation with maximum rpm to mix the resin components and to assist in shredding the capsule skin, to avoid gloving. Overview

Effects that Low Pre-tension has on the Roof Beam Low pre-tension can cause lower roof ply's to separate more readily Reduces Beam effectiveness Causes of Low Pre-tension 1)Maintenance issues on rig 2)Not waiting until the rig has stalled when tightening

Effects that Bond Strength has on the Roof Beam Poor Bond Strength caused by: 1.Under mixing 2.Over mixing 3.Oversize drill hole diameter Poor bond strength reduces beam strength

Jennmar Australia Supporting the Mining Industry above and below Questions Jennmar Australia Pty Ltd