ACARP ACARP ACARP ACARP
Open Cut

Investigations For Open Pit Geomechanics Using Geophysical Logs

Open Cut » Geology

Published: May 13Project Number: C20025

Get ReportAuthor: Peter Hatherly, Terry Medhurst,Binzhong Zhou | Coalbed Geoscience, PDR Engineers, CSIRO

With the move towards deeper open cut coal mines, there is a need for on-going developments in technologies which allow management of geotechnical risk and the maintenance of high levels of productivity. Areas where development is required include highwall stability monitoring, semi-automated highwall mapping, 3D modelling and effective overburden characterisation. This project is concerned with the last of these and is based upon a new approach to characterising rock masses using conventional borehole geophysical logs.

 

Of particular interest are the composite rock mass failures that involve intact material as well as fracture and shear on existing defects. Composite failure has been identified as a key mechanism for many of the highwall failures that occur. While extension and stress provide the triggers for the failure, it is also clear that better characterisation of the overburden is required. In this regard, traditional defect logging alone often does not provide adequate information and face scanning methods require a geomechanical context against which to assess their results. Integration of highwall photogrammetry and image processing results with other datasets is difficult.

 

The approach to using geophysical logs has been developed through previous ACARP projects for underground coal mining and has resulted in a new rock mass rating called the Geophysical Strata Rating (GSR). The GSR was developed to address similar problems in underground mining where 3D models of the rock mass are needed to improve the assessment of roof stability, cavability and the interaction of longwall equipment with the surrounding strata.

 

The geophysical logs allow objective measurement of rock properties within a borehole and at great detail. At coal mines, geophysical logs, primarily natural gamma, density and sonic logs are obtained in most exploration boreholes. The GSR is an empirical rock mass rating scheme based on an interpretation of the logs. It aims to provide a measure of rock quality at every depth point in the geophysical log which is independent of rock type and depth. In this way, GSR is fundamentally different to the UCS estimates often made from sonic logs.

 

Given the large amount of data that is available, it is possible to create 2D and 3D models of the in-situ rock mass. In addition to models of GSR, it has been found that models showing the clay content of the strata that are present provide a very useful map of the lithological variation in the rocks forming the interburdens between the coal seams of interest. Within these models, it is possible to place additional information rock mass properties and defects in a meaningful spatial context.

Underground

Health and safety, productivity and environment initiatives.

Underground

Open Cut

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

Recently Completed Projects

C19024Establishing Ecologically Sustainable Mine Water Release Criteria In Seasonally Flowing Streams

Extreme rainfall conditions in the Fitzroy Catchment over an approxi...

C25030Coal Mine Open Pit Final Void Closure And Relinquishment - Addressing Uncertainty In Coal Mine Environmental Planning

This report addresses uncertainties faced by coal mine operators whe...

C27046Estimation Of True Deformation Vector From Slope Radar Monitoring

Slope deformation radar monitors are now widely used in open cut coa...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C27004Improving Coal Flotation With Oscillatory Air Supply

This report provides detailed information on coal flotation with os...

C25018Improving Solids Recovery And Moisture Reduction In Ultrafine Coal Dewatering

This report provides detailed information on fine coal dewatering in...

C27028Lab Froth Flotation Testing Guide With Coal Quality

Correct outcomes from laboratory froth flotation testing in coal bor...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C26039Nanoporosity In Cokes: Their Origin, Control And Influence On CO2 Reactivity

This project using the outcomes of previous project C24060, examine...

C28063A Comprehensive Technical Review Of High-Efficiency Low-Emission (HELE) Pulverised Coal Combustion Technologies For Power Generation

Research and development has been undertaken worldwide to realise co...

C28064Carbon Structure Transformation During Coking Of Australian Coking Coals: Better Understanding The Coke Formation

Carbon structures of coke that are formed during the plastic layer a...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

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...

C26004CFD Modelling Of Reverse Thermal Oxidisers For VAM Abatement - CFD Modelling Of Fixed-Bed RTO Devices

The project is part of a larger multi‐phase program of study a...

C27058Technological Assessment Of A Recycle Reactor For VAM Abatement

Underground coal mining emits high volumes of methane, diluted in ve...

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

NERDDC

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

NERDDC