Monitoring and Stability Assessment of a Punch Longwall Roadway Developed using Highwall Mining Technology

Underground » Mining Technology and Production

Published: December 00Project Number: C9007

Get ReportAuthor: Baotang Shen, Mary Fama, J Boldna, D Adhikary, A Maconochie. Appendix III - David Hill | CSIRO Exploration & Mining, GeoTek Solutions. Appendix III - Strata Engineering

This report describes the results of ACARP research project C9007. The project was established to assist an innovative roadway development trial at Kenmare 2, South Blackwater Mine. A continuous highwall mining system (CHM) was used to develop the roadways for a proposed punch longwall operation at Kenmare 2. The aim of the research project was to monitor, evaluate and model the roadway performance during the initial roadway driveage and subsequent widening using CHM.

The roadway development trial was conducted in January 2000. Significant roof falls were experienced, which contributed to much slower mining progress than anticipated and the operation was terminated prematurely. Despite this, most of the tasks originally proposed within the ACARP project have been completed. They comprise:

  • Monitoring of roof deformation of a punch longwall roadway.
  • Laboratory investigation of roof rock properties.
  • Analysis and modelling of roof behaviour of punch longwall roadways.

The main outcomes of the ACARP research project are the observations and conclusions listed below:

  • Extensive roof falls, mostly in a range from 0.3 m to 0.7 m, were observed to have occurred in a large portion of the roadway.
  • The roof rocks within 1.5 m from the coal seam were tested to be weak.
  • An improvement in roof stability with penetration distance was observed and it could be due to (1) a general increase in the strength of the roof rocks and bedding planes; (2) an increase in horizontal to vertical stress ratio and thus the magnitude of the horizontal stress.
  • The deep-hole surface extensometers successfully recorded data associated with the development of an unsupported roof fall at 41 m inbye. The stand-up time of the roof was measured to be 10 hours at this location after driveage of the roadway.
  • The numerical model and the analytical formula designed to analyse the span stability were demonstrated to be effective in predicting the roof falls.

The experience at Kenmare 2 highlights the significance of geological variation and the need for improved understanding of the roof behaviour. Despite the site investigation and geotechnical assessment performed before highwall mining commenced, it is clear from this experience that future highwall mining operations of this nature require more specific information from the area to be mined. This is especially important when mining near to the highwall and in proximity to pre-blasted slopes or in other areas of doubtful roof rock quality.

Despite the early termination of the mining trial, the ACARP research project as a whole is considered to be successful, and the outcomes will be useful for future punch longwall and highwall mining operations. The instabilities of the unsupported roadway span experienced during mining were able to be observed and monitored. This provided a unique opportunity to study the failure mechanisms of unsupported spans at shallow depths and to verify the existing prediction tools.

The innovative method of using a CHM system to develop roadways for a punch longwall operation could well be successful at a site with conditions more favourable to highwall mining.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C27039True Triaxial Strength Of Coal Measure Rocks And Its Impact On Roadway Stability And Coal Burst Assessment

Rocks in the ground are subject to a range of stresses. The stresses...

C3063Underground Vehicle Design Standards And Statutory Implications

The Australian underground diesel vehicle fleet has evolved since di...

C3064Conveyor Belting And Lagging Shear Characteristics - Drive Drum Slip

The primary aim of this project was to investigate the relationsh...


Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C29021Assessing The Impact Of Consecutive Night Shifts On Night-Time Alertness, Daytime Sleep And Timing Of The Circadian System

In the Australian coal mining industry, most guidelines for managing...

C33037Quantifying Recharge To Groundwater Systems In The NSW Coalfields (Sydney, Gunnedah And Gloucester Basins)

The purpose of this project was to estimate the rate of diffuse rec...

C26029Geological Controls On Fluorine And Phosphorus In Bowen Basin Coals

Increasing global restrictions on fluorine in product coal prompted ...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C27064Dry Beneficiation Using FGX And X-Ray Sorters

Conventional dry processing methods engage a single beneficiation de...

C26010Multi-Sloped Screening Efficiency With Changing Strokes, Frequencies, Feed Solids And Feed Rates-Pilot Plant Study

Optimising multi-sloped screens is often described as an art and the...

C28059Impact Of Water Quality In Coal Handling And Preparations Plants

The objective of this project was to deliver a concise reference do...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

C27054Optimisation Of A Thermal Flow Reversal Reactor For Ventilation Air Methane Mitigation

Ventilation air methane (VAM) generally accounts for 50-85% of the t...

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL) - Phase 2 Demonstration In A Packed Bed Reactor

An alternative approach to high temperature oxidation of ventilation...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community


National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook