Where do the data come from?

Hadjigeorgiou, John

doi:10.36487/acg_rep/1201_19_hadjigeorgiou

Cited by 10 publications

(10 citation statements)

References 15 publications

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“…In several mining jurisdictions, codes and standards are available for reporting exploration data (JORC 2012, CIM 2003, but similar codes or guidelines are not readily available or require compliance for geotechnical mine design. This suggests that the level of confidence in geotechnical design data is potentially less than for the data used for resource and reserve estimation (Hadjigeorgiou 2012;Haile 2004;Read 2009;Steffen 1997). A strong case has been made by Terbrugge et al (2009) and Steffen (2014) for the use of confidence categories in the data for slope design.…”

Section: Introductionmentioning

confidence: 99%

Quantifying influence of drilling additional boreholes on quality of geological model

Fillion

Hadjigeorgiou

2019

Can. Geotech. J.

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Geotechnical stability analysis in open pit mines requires access to a representative geotechnical model. The confidence level in the collected geotechnical data influences slope design. This paper investigates the influence of the number of boreholes, drilled to collect geological information, on the quality of one component of the geotechnical model, the geological model. The number of boreholes influences the number of rock core samples collected for the identification of rock type, the definition of geotechnical domains and their boundaries within the rock mass. A challenge in the definition of the geotechnical domains is the determination of the drill hole density that minimizes the variation in the interpreted geological model from the actual rock mass. In order to quantify the influence of the drill hole density, boreholes are simulated in the most recently updated geological model for three mine sites. The simulated drill hole density increased progressively until the variation of the interpreted section, compared to the original section, is minimised. A classification strategy was developed to determine the complexity level for each geotechnical domain. Furthermore, a series of empirical quantitative guidelines are presented prescribing the minimum drill hole density per domain complexity, while limiting variations from the actual rock mass.

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Section: Introductionmentioning

confidence: 99%

Quantifying influence of drilling additional boreholes on quality of geological model

Fillion

Hadjigeorgiou

2019

Can. Geotech. J.

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“…However, this design concept is not necessarily appropriate, or applicable for deep mining projects. A more applicable design process is a continuous process where several of the steps are either run in parallel or through several iterations (observations are made to continually update designs), (Hadjigeorgiou 2012). A continuous and iterative design process is necessary in mining geomechanics where problems are nearly always considered data-limited; any actual data collected from samples are only a very small fraction of the field scale rock mass (Bawden 2015).…”

Section: Introductionmentioning

confidence: 99%

The unanticipated performance of a weak massive rock mass at depth and the added value of observational engineering

Kalenchuk¹,

Hume²,

Morin³

et al. 2017

Proceedings of the International Conference on Deep and High Stress Mining

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A site investigation for the Fresnillo shaft expansion program revealed that mylonitic shale, characterised as massive but weak, would be encountered near the planned shaft bottom and in the vicinity of large excavations required for the proposed crusher station and ore handling infrastructure. The rock mass is sparsely jointed, however, fails readily along graphitic planes of weakness in the mylonitic fabric. At roughly 950 m depth, excavations within this weak rock mass were expected to squeeze and excavation support was designed accordingly. The mylonitic shale was encountered within a ramp in a nearby region of the mine prior to shaft sinking and was observed to stand-up well with minimal ground support at 790 m below surface. This paper demonstrates the value of observational engineering where observed ground behaviour was back-analysed to improve the site geomechanical model, thus, providing an opportunity for design optimisation and risk mitigation for a major shaft expansion project.

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“…It should be recognised, however, that there was a limited number of mining case studies used to develop these systems. A review of the limitations of rock mass classification systems have been provided amongst other by Milne et al (1998), Palmstrom and Broch (2006) and Hadjigeorgiou (2012).…”

Section: Introductionmentioning

confidence: 99%

Empirical ground support design of mine drives

Potvin

Hadjigeorgiou²

2015

Proceedings of the International Seminar on Design Methods in Underground Mining

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The majority of Australian and Canadian underground hard rock mines rely on the Norwegian Method of Tunnelling ground support recommendations for preliminary design recommendations. This is the case during the pre-feasibility and feasibility stages where the Q-system is used to select the support standards. This is usually accompanied by a limit equilibrium wedge analysis and rules of thumb. It follows that as the mine advances more geomechanical data becomes available, including rock exposures that allow for an update of the ground conditions and revision of the recommendations. As the mine develops, the ground support standards evolve further. At any given time, the implemented ground support systems for the different ground conditions are documented and updated in the mine's ground control management plan (GCMP). This paper addresses some of the limitations of the Norwegian Method of Tunnelling as a ground support design tool for mining excavations. The results of a comprehensive review of GCMPs, successfully implemented in Australian and Canadian hard rock underground mines, are the basis of newly developed empirical guidelines calibrated to mining conditions and ground support.

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Where do the data come from?

Cited by 10 publications

References 15 publications

Quantifying influence of drilling additional boreholes on quality of geological model

Quantifying influence of drilling additional boreholes on quality of geological model

The unanticipated performance of a weak massive rock mass at depth and the added value of observational engineering

Empirical ground support design of mine drives

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