GEOTECHNICAL TELEVIEWER INTERPRETATION
GEOTECHNICAL TELEVIEWER INTERPRETATION (GTI)
D&S have developed an innovative and unique processing methodology – GTI that accurately evaluates the full suite of geotechnical properties and structural characteristics of a rock mass using downhole televiewer surveys. Pre-existing and open drillholes can be surveyed using the televiewer reducing the amount of diamond drilling required whilst sufficient, accurate data is collected for geotechnical studies. Significant costs savings can be realized without restrictions on data quality and quantity.
GTI processing methodology has enabled the identification and classification of structure type, surface roughness, infill nature, geotechnical domain, rock strength, rock quality designation (RQD) from televiewer data. Some validated and calibrated geotechnical logging of diamond drill core for the identified lithological units in the area of interest is required to generate a reliable geotechnical dataset from televiewer surveys.
GTI has application in any diamond or percussion drillholes including RC and RAB drillholes.
GTI has been specifically developed to optimise geotechnical drilling programs, hence reducing the cost and time required for data acquisition whilst improving the quality and confidence of structural data and mechanical rock mass property data.Read Article
DIRECT COMPARISON IMAGES BETWEEN DIAMOND AND RC DRILLHOLE
Twin Televiewer Images from Diamond Drillhole Initially and Post Reamed Using RC Drilling.
- Rock type
- Geotechnical domain
- Rock Quality Designation (RQD)
- Number of discontinuities
- Type of discontinuities
- Number of discontinuity sets
- Roughness of discontinuities
- Fill of discontinuities and thickness
- Dip and Dip Direction of Discontinuities
- Back calculated Alpha and Beta angles for Terzaghi Weighting DIPs plot
- Strength index of the rock
- Failure mechanism based on defect type and orientation in conjunction with UCS and Triaxial tests
Major Open Fracture with Rough Irregular and Soft Infill
Accurate geological structure orientation can be useful in 3D modelling of orebody, lithology and structure.
Geological structure type includes:
- Rock type
- Geological contact
- Healed Joint
- Open Joint
- Vein including thickness
- Bedding and Foliation
- Micro Fault and Fault zone
Borehole Breakout can be identified from televiewer data, obviously from acoustic televiewer Travel Time and Amplitude signal strength.
Borehole Breakout appears in drillholes normally as a pair opposite and perpendicular to the maximum stress orientation. Vast reliable data can be acquired plus far more efficiency, and economy to identify stress orientation from televiewer data using pre-existing open drillhole in comparison to drill new diamond drillholes for acoustic emission (AE) tests.
Interpretation of borehole breakout includes:
- Breakout size
- Breakout orientation
- Rose plot with maximum stress orientation