Fitness of Longwall Powered Supports

Underground » Mining Technology and Production

Published: April 05Project Number: C12007

Get ReportAuthor: Bob Trueman | JKMRC, University of Qld

Powered supports account for the majority of the capital expenditure for a longwall panel and are fundamental to the success of the operation. The adequacy of the support capacity for the geotechnical and geological conditions that will be met during mining and the set pressures can significantly impact upon ground control and equipment life.

The research has developed a new geotechnical model of the support roof-strata interaction process that links support load-time characteristic patterns observed during longwall operation to geotechnical and mining conditions. The model permits determination of the adequacy of the support and appropriateness of the set pressures for the conditions. This new model was developed after a comprehensive study of the existing methodologies for support capacity selection had concluded that they were all fundamentally flawed or oversimplified and therefore ineffective.

The geotechnical model links a standard classification of the roof conditions to expected loading patterns. Its application to a variety of mining conditions leads to the development of an empirical database which can be used as a tool to estimate the support requirements and operating strategies that will be effective in a greenfields situation. The research programme made detailed studies in 5 mining panels at four mines. The geotechnical conditions encountered cover a fair percentage of those currently encountered within Australia.

The research relied upon analysis of support loading cycles for every support in the face over a total advance at all the mines of 1,590 m. Approximately 500,000 loading cycles were analysed. This analysis was made possible by the development of new software that accepts the raw data files from longwall monitoring systems and makes accurate identification of the loading cycles. The software calculates face advance and was typically in error by only one or two meters in 150 m of advance even in worst case scenarios. While the software was operated on historical data files during the research, with some further development it could be operated in near real-time. The new software was developed by the research team prior to the commencement of the project after trials of existing software such as 'Shields' demonstrated that they were not capable of correct load cycle delineation.

The extensive data analysis, which included a detailed study of mine geology and operating conditions in the areas of support data logging, has provided the basis for a comprehensive validation of the geotechnical model. In all areas studied, the loading patterns expected from the geotechnical analysis were observed.

In addition to an assessment of support-strata interaction for normally operating supports, the impact of faulty support components on roof conditions was able to be determined. Faults on even a few isolated supports were found to potentially lead to localised ground control problems and costly production delays. The software can be used to identify these faulty support components.

The immediate outcomes of the research were the identification and quantification of problem areas at the sites where analyses were carried out and recommendations as to the best way to avoid or alleviate the impact of these problems.

There are three quite separate "products" arising from the research project.
  • An empirical database has been developed.
  • A diagnostic tool in the form of a computer code has been developed.
  • A "bureau" type service can be provided where historical data can be analysed by the project team.

Towards the end of the project, it became clear that the industry had a strong interest in the further development of the existing software into a well-structured commercial quality product that would permit mines to analyse data from the longwall almost immediately. The transfer of the technology developed in the research project is being actively pursued.


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

C26029Geological Controls On Fluorine And Phosphorus In Bowen Basin Coals

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

C28033Raw Ash To Yield Relationships

Correct outcomes in yield predictions for product ash from coal bore...

C27038Establishing Self-Sustaining And Recognisable Ecological Mine Rehabilitation

In recent years an increasing interest has been placed on mining ope...

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