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In order to deliver a quality shotcrete and concrete product underground for the extensions to the Cullinan Diamond Mine operations it was decided to develop a new, simpler concrete product to meet underground support requirements. The aim was to develop a concrete product that not only reduced costs but also met the performance criteria of the current range of concrete products used on Cullinan Diamond Mine, a 25, 45 and 60 MPa concrete and a fibre reinforced wet shotcrete. The concrete product batching and delivery system was to be from surface as opposed to the current underground batching systems. The operational principle was to include an automated surface batching plant with delivery of the concrete product to a borehole containing suspended pipelines delivering to an underground storage facility from where the product is delivered to the working area by further pumping or agicars. Keywords: concrete, shotcrete, full flow, frictional loss, pipeline transport, positive displacment pump

Jan 1, 2006

By F. Riedel

In May 2009 a test work programme was carried out at the sorting laboratory of CommodasUltrasort in Germany which was aimed at establishing the efficiency of X- ray transmission sorting for the recovery of unliberated diamonds in a size range of +8mm. A PRO Tertiary XRT belt sorter with a working width of 600mm and a belt speed of -3mJs was used for the test work. Dual energy X-ray transmission sorting is a type of sensor-based sorting which uses an X-ray scanning system, The attenuation of the transmitting X-rays is measured at two different energy levels, Thereby it is possible to eliminate the effect of the particle thickness on the measurement result. The effective measurement results in a classification by elemental order based on the periodic table.

Jan 1, 2010

By F. C. Harris, S. J. Gaab, J. Sattarvand, S. Duzgun

Underground mines are inherently dangerous due to potential hazards such as fires, explosions, and caving of rock. Although these events are rare, once they occur a speedy and safe egress of mineworkers is critical to survival. Static evacuation systems use exit signs or directional lines but can get obstructed or be hardly visible in smoky or dusty conditions. This paper presents the investigation of the effectiveness of a smart evacuation technology in underground mining, where a real-time guidance system leads individuals on an optimised path to the egress while avoiding danger zones, compared to conventional practices. Participants simulated an evacuation from a virtual reality mine, using the conventional system and the smart evacuation system with real-time guidance. The highest reduction in evacuation time using the smart method amounted to nearly 40% on average. Moreover, 83% of participants preferred the smart guidance system, and agreed that it could enhance safety.

Sep 1, 2021

By P. J. Bartlett

Premier Diamond Mine exploits a kimberlite orebody using cave mining methods. A drilling level is established at the base of a block of ore to effect undercutting that leads to caving of the overlying ore. A second level is developed some 15 metres below the undercutting level to allow extraction of the ore once it has caved. As much as 45 per cent of the rock is removed on the extraction level creating a series of pillars. Undercutting creates abutment stresses, as high as 3 times the virgin stress, which affect the rock mass to a distance of 20 metres from the undercut face on the undercut level and on the extraction level 15 metres below. If the extraction level is completely developed prior to undercutting, where stress levels exceed 20 percent of the rock mass strength, extensive rock mass and support damage occurs as the undercut passes overhead. Rock mass damage takes the form of movement along existing joints and minor shear failure through intact rock. Support damage takes the form of cracking in rigid concrete linings. Where induced stresses exceed 50 per cent of the rock mass strength it is often impractical to keep excavations on the extraction level open. Rock mass damage takes the form of extensive failure of the rock in shear which evidences itself as propagation of the fracture zone around tunnels and footwall heave. Support damage results in destruction of shotcrete linings and concrete footwalls. As the interbolt support fails, badly fractured rock ravels around the steel tendons. Observation and monitoring at Premier Mine and on other cave mines has shown that induced stress levels and consequent damage are a function of :?the extraction ratio on the undercut and extraction level prior to undercutting ?the shape of the undercut face ?the rate of undercut advance ?the distance of leads and lags between adjacent tunnels on the undercut level. To ensure the stability of excavations, all of the above parameters must be carefully planned and the planned mining sequence rigidly enforced. The minimum of development is completed on the extraction level prior to the undercut passing overhead. Required development is then rapidly completed once the area has been de-stressed. Support is installed in three phases: ?Rockbolts are installed as soon as excavations are developed ?Wire mesh, steel tendon straps and a layer of shotcrete sufficient to protect the mesh and straps from damage by blasting and LHD loading is installed as soon as practical thereafter. Inevitably the shotcrete lining has to be replaced once the undercut has passed overhead.. ?Rigid shotcrete linings and concreted footwalls are completed only after the undercut has passed overhead and the area has been de-stressed.

Jan 1, 2000

By T. Kagogo, M. Neser, C. Knobbs, E. Gerryts

"Contrary to the way it is often portrayed, the average organization or company is far from being a cold, calculating machine. It is actually a highly emotive place where interaction with people is a fundamental part of its ability to perform satisfactorily.The company, through its employers, expects employees, including new graduates, to have the ability to cope adequately with this emotive environment. The graduate is frequently unable to meet this expectation because he/she has not been developed to do so. Technical knowledge is his only asset. This deficiency manifests itself in leadership shortcomings, both intrapersonal and interpersonal. Further analysis reveals a deficiency in three elements of leadership - self-awareness, oral communication, and an ability to work cooperatively in teams.To address these three elements of leadership, Sasol Coal, a subsidiary of the big petrochemical company in South Africa, sponsored a leadership programme at the University of Pretoria for their final-year bursary students in the faculty of Engineering. This programme, the Sasol Engineering and Leadership Academy (SELA), consisted of a number of interventions designed to address the three areas of self-awareness, oral communication, and cooperative behaviour in teams. These interventions varied from an intrapersonal nature to interpersonal aspects. Psychometric assessments were followed by experiential modules dealing with the three constructs.SELA was evaluated at the end of the year. The results showed a positive shift in the main constructs of self-awareness, communications, and cooperation. This was measured quantitatively and qualitatively. Conclusions were drawn and recommendations for improving the programme were proposed."

Jan 1, 2014

By C. Knobbs

Contrary to the way it is often portrayed, the average organization or company is far from being a cold, calculating machine. It is actually a highly emotive place where interaction with people is a fundamental part of its ability to perform satisfactorily. The company, through its employers, expects employees, including new graduates, to have the ability to cope adequately with this emotive environment. The graduate is frequently unable to meet this expectation because he/she has not been developed to do so. Technical knowledge is his only asset. This deficiency manifests itself in leadership shortcomings, both intrapersonal and interpersonal. Further analysis reveals a deficiency in three elements of leadership ? self-awareness, oral communication, and an ability to work cooperatively in teams. To address these three elements of leadership, Sasol Coal, a subsidiary of the big petrochemical company in South Africa, sponsored a leadership programme at the University of Pretoria for their final-year bursary students in the faculty of Engineering. This programme, the Sasol Engineering and Leadership Academy (SELA), consisted of a number of interventions designed to address the three areas of self-awareness, oral communication, and cooperative behaviour in teams. These interventions varied from an intrapersonal nature to interpersonal aspects. Psychometric assessments were followed by experiential modules dealing with the three constructs. SELA was evaluated at the end of the year. The results showed a positive shift in the main constructs of self-awareness, communications, and cooperation. This was measured quantitatively and qualitatively. Conclusions were drawn and recommendations for improving the programme were proposed.

Jan 1, 2014

By S. Bellec

A leaching model for gold ore that takes into account the impact of cyanide and oxygen concentrations as well as gold surface exposure on leaching performance is developed. Cyanide consumption is estimated by an empirical model that is a function of ore particles size distribution as well as cyanide, copper and sulphur concentrations. The proposed model has been validated by data from laboratory leaching tests on the Sleeping Giant gold mine ore. Keywords: gold leaching, modelling, exposure surface.

Jan 1, 2009

By J. Betzhold

Knowing more about an orebody makes it easier to exploit it profitably. Many orebodies are made up of different rock types, alteration zones or mineralogical ensembles: oxides versus sulphides or facies with different metallurgical properties for example. Being able to model the spatial layout of these different facies is vital to good mine planning and management. Kriging cannot be used to generate numerical models of orebodies with complex geometric patterns because it gives too smooth an image. Over-smoothing has the meaning of changing the natural selectivity. Conditional simulations are required to do this kind of model respecting the natural variability: honouring the natural selectivity, dilution and ore loss. Standard geostatistical simulations cannot duplicate many of the complex spatial relationships seen in the earth sciences, such as differently orientated facies, sets of conjugate veins or ore types where certain facies cannot touch. After a presentation of the case study, it will be shown why traditional methods for simulating indicators like the sequential indicator simulations, or the truncated gaussian method, cannot be used to simulate it. Plurigaussian simulations are then introduced and shown to be more powerful than the previous methods in their range of application. This is confirmed by the case study treated; a Chilean copper deposit, for which the plurigaussian simulations are seen to respect the different orientations of the individual facies as well as honouring the facies seen in drill holes, and respecting the proportion of each facies even if this varies in space (e.g. increases or decreases with depth). Key words: geostatistics, indicators, conditional simulation, plurigaussian method, copper variability.

Jan 1, 2000

By G. B. Quaye

The deep level gold mining environment is characterized by high stresses that give rise to intense mining induced fracturing of the rock mass surrounding the stopes. In a geologically disturbed region where the intensity of mining induced stress fracturing is high, the degree of faulting and/or the frequency of other geological features such as joints may pose serious strata control problems. Unfavourable intersection of these discontinuities namely, faults, joints and mining induced stress fractures tend to divide the immediate hangingwall into unstable keyblocks which, if not supported, may result in extensive falls of ground. Effective support strategies therefore demand detailed investigation of the predominant inclinations and orientations of these discontinuities. The orientations and inclinations of these discontinuities surrounding a deep level stope have been measured. The results are projected onto the lower hemisphere of a stereographic net to determine the factors that contribute to the falls of ground in the stope. The analyses reveal that unfavourable intersection of these discontinuities divides the immediate hangingwall into unstable wedges that may become dislodged between support units.

Jan 1, 1998

By T. Tholana

South Africa hosts some of the world?s largest known resources and reserves of minerals that are strategically important to the global economy. The country?s mining industry contributes significantly to the national economy in terms of gross domestic product, export earnings, corporate tax receipts, remuneration earnings, and employment. Platinum, gold, and coal are significant minerals because they make the largest individual contributions to these economic indicators. Several factors impact the cash cost performance of operations that mine these minerals, thus affecting the future sustainability of these operations, which are generally ?price-takers?. It is therefore important that the cash cost performance of operations for these key minerals is analysed. Commercially available industry cost curves can be used for such analysis. However, some companies may not be able to afford to purchase these curves. This paper presents a simple Microsoft Excel® algorithm for constructing the curves. It also demonstrates how the constructed industry curves were used to analyse the cash cost performance of South African mining operations for the three selected minerals for the period 2007 to 2011, which included the 2008 global financial crisis. The analysis revealed that the operations were affected by several global and local factors during the review period. The work reported in this paper is part of an MSc research study at the University of the Witwatersrand. Keywords cost curve algorithm, economies of scale, cash cost performance

Jun 1, 2013

By P. Altounyan, K. Akermann, T. Van den Berg

Amandelbult Mine is currently undertaking a trial to mechanise the mining of the UG2 reef through the introduction of room and pillar mining. As part of the trial, a system of managing the control of the hanging wall has been introduced, based on systems and technology that are proving successful in the nearby coal mining industry. The principal features are the use of a high bond strength, stiff bolting system which can be easily installed to a high standard, and a range of in situ tests and measurements to optimise the level of support installed to control the movement of the hanging wall. The rock bolt system and the measurements and tests described are new to the platinum mining industry. The paper describes these systems and their adaptation and application to hard rock mining. La Mine d’Amandelbult est actuellement dans des essais en vue de mécaniser l’extraction dans la veine UG2 grâce à l’introduction d’une exploitation par chambres et piliers. Dans le cadre de ces essais, un système de gestion de la paroi suspendue a été introduit, base sur des systèmes et une technologie qui prouvent donner de bons résultats dans l’industrie voisine d’extraction de la houille. Les caractéristiques principales sont l’utilisation d’un système de verrouillage raide et à forte adhérence qui peut être installé à un haut niveau de qualité et une gamme d’essais et de mesures in situ pour optimiser le niveau de soutien installé pour contrôler le mouvement de la paroi suspendue. Le système de verrouillage de la roche ainsi que les mesures et les essais décrits sont une nouveauté dans l’industrie minière du platine. La communication décrit ces systèmes ainsi que leur adaptation et leur application à l’exploitation minière en roche dure. Amandelbult Mine unternimmt gegenwärtig einen Test um den Abbau des UG2 Riffs durchEinführung des Kammerpfeilbau zu mechanisieren. Als Teil dieses Tests wurde ein System zur Kontrolle der Stollenfirstes eingeführt, welches auf jenen Systemen und Technologien basiert, diesich im nahe gelegenen Kohlebergbau als erfolgreich erwiesen. Die prinzipiellen Charakteristikasind der Gebrauch von einem steifen Bolzensytem mit hohem Verbundwiderstand die leicht zueinem hohen Standard gebracht werden können, und eine Reihe von in-situ Tests und Messungenum das Niveau der installierten Unterstützung zu optimieren, und um die Bewegung desStollenfirstes zu kontrollieren. Das Gesteinsbolzensystem, die Messungen und die Tests, diebeschrieben werden, sind neu in der Platinbergbauindustrie. Diese Arbeit beschreibt diese Systeme, deren Anpassung und Anwendung im Hartgesteinsbergbau.

Jan 1, 2003

By R. Webster

"Daniel Krige’s influence on soil science, and on soil survey in particular, has been profound. From the 1920s onwards soil surveyors made their maps by classifying the soils and drawing boundaries between the classes they recognized. By the 1960s many influential pedologists were convinced that if one knew to which class of soil a site belonged then one would be able to predict the soil’s properties there. At the same time, engineers began to realize that prediction from such maps was essentially a statistical matter and to apply classical sampling theory. Such methods, though sound, proved inefficient because they failed to take account of the spatial dependence within the classes.Matters changed dramatically in the 1970s when soil scientists learned of the work of Daniel Krige and Georges Matheron’s theory of regionalized variables. Statistical pedologists (pedometricians) first linked R.A. Fisher’s analysis of variance to regionalized variables via spatial hierarchical designs to estimate spatial components of variance. They then applied the mainstream geostatistical methods of spatial analysis and kriging to map plant nutrients, trace elements, pollutants, salt, and agricultural pests in soil, which has led to advances in modern precision agriculture. They were among the first Earth scientists to use nonlinear statistical estimation for modelling variograms and to make the programmed algorithms publicly available. More recently, pedometricians have turned to likelihood methods, specifically residual maximum likelihood (REML), to combine fixed effects, such as trend and external variables, with spatially correlated variables in linear mixed models for spatial prediction. They have also explored non stationary variances with wavelets and by spectral tempering, although it is not clear how the results should be used for prediction. This paper illustrates the most significant advances, with results from research projects."

Jan 1, 2015

By T. Marin, J. E. Seccatore, M. Cardu

The most energy-intensive process in the mining industry is particle size reduction – comminution. The first phase of this process is blasting to fragment the rock from the initial Boussinesq’s halfspace size. Scientific literature demonstrates that the output of a blast in terms of fragment size distribution can be manipulated by varying the specific charge (powder factor) and charge distribution. This study focuses on the influence of blasting on the internal resistance of the blasted fragments; in particular the influence of the spatial distribution of charges. Small-scale blasts were performed on 14 marble blocks using different powder factors and charge distributions. Three control blocks were fragmented by mechanical means for comparison. The results show the correlations between charge distributions and the specific energy of mechanical comminution. Opportunities for adjusting charge diameter and distribution in opencast blasts to improve the performancet of comminution circuits are discussed.

Aug 8, 2024

By P. Syrjänen, Lovén. P.

Because geostatistics together with block modeling has not been studied in detail before in the rock mechanics, a two-year research program to investigate the practical use of geotechnical modeling was started in Finland in 1999. According to research work results block modeling gives good estimate of overall rock mass quality but it can not identify individual structures like faults and narrow weakness zones. Weakness zones and faults should be mapped from drill cores, surface mapping, geophysical methods etc. and manually generate 3-D structural model. Rock mechanical 3-D modeling can be used for preliminary stope dimensioning and preliminary reinforcement design. Detailed design needs rock quality mapping from drifts during excavation work. La géostatistique associée à la modélisation par blocs n'ayant pas été étudiée en détail jusqu'à présent dans la mécanique des roches, un programme de recherche sur deux ans visant à examiner l'utilisation pratique de la modélisation géotechnique a été lancé en Finlande en 1999. D'après les résultats des travaux de recherche, la modélisation par blocs donne une bonne estimation de la qualité générale de la masse rocheuse mais elle ne permet pas d'identifier les structures individuelles comme les failles et les zones géologiquement dégradées étroites. Ces zones et failles devraient être cartographiées à partir de carottes de sondages, d'une cartographie de surface, de méthodes géophysiques, etc. et générer manuellement un modèle de structure 3D. La modélisation mécanique des roches en 3D peut être utilisée pour un dimensionnement de la chambre et un plan d'armature préliminaires. Un plan détaillé nécessite l'élaboration d'une cartographie de la qualité des roches des galeries lors des travaux d'excavation. Da man früher Geostatik und Block-Modellieren in der Gebirgsmechanik nicht detailliert untersuchte, wurde 1999 in Finnland ein zweijähriges Untersuchungsprogramm in Angriff genommen. Aufgrund der Untersuchungsergebnisse ergibt das Block-Modellieren eine gute Beurteilung der gesamten Gebirgsmassenqualität, kann jedoch einzelne Strukturen wie Verwerfungen und kleine Schwachzonen nicht identifizieren. Schwachzonen und Verwerfungen müssen demnach aus Bohrkernen, oder mit Hilfe von Oberflächenkartierung, geophysischen Verfahren usw. ermittelt und danach ein 3-D-Strukturmodell manuell erstellt werden. Felsmechanisches 3-D-Modellieren ist für die vorbereitende Abbaudimensionierung und für die vorbereitende Bewehrungsplanung verwendbar. Ein detaillierter Entwurf benötigt die Kartierung der Gesteinsqualität aus den Gesteinsstrecken während der Ausbrucharbeiten.

Jan 1, 2003

By S. O. Choi, H. -S. Shin, W. -K. Song

Nuclear waste should be disposed with the best warranty for the national health and welfare. Among the several repository systems, the deep underground disposal is considered to be a most suitable system in Korean peninsula. However it demands basically the comprehensive stability analysis such as the behaviour of discontinuities in rock mass, the behaviour of ground water, and the reaction of rock stress according to the heat from the nuclear waste. For these purposes, the underground nuclear waste disposal repository was simulated in two- and three- dimensions. It shows that emphasis will be given to the thermal conductivity of discontinuities and the thermal convection of ground water as well as the thermal stress generated by the nuclear waste for design and construction of repository system, and they should be obtained from the field measurements. Déchets nucléaires devront tre déposés avec la meilleure garantie pour la santé et le bien public. Parmi les plusieurs systèmes de dépôt, la disposition en souterrin profond est considérée au système le plus approprié en Corée. Pourtant ce système demande essentiellement l’analyse éten-due de stabilité comme le comportement des discontinues en masse rocheuse, le comportement de l’eau souterrin et la réaction des contraintes de roche selon la chaleur depuis les déchets nucléaires. Pour ce but, le dépôt des déchets nucléaires en sous-sol a étè simulé en deux et trois dimensions. Il montre que l’accent sera donné à la conductivité thermale des discontinues et la convection thermale de l’eau souterrin aussi bien que la contrainte thermale générée par les déchets nucléaires pour le plan et la construction du systèmes de dépôt, et ils devront tre obtenus depuis les mesures sur place. Die Kernwüste muß mit der besten Gewähr für die nationale Gesundheit und die Wohlfahrt angeordnenet werden. Unter einigem Fundgrubesystem, das tief unterirdisch Wegwerfen werde in Betracht das passendest System in der koreanisch Halbinsel gezogen. Jedoch, es verlangt grundzätzlich die umfassend Stabilitätsberechnung so wie das Behnehmen mangelnder Konti-nuität in der Felsmasse, das Behnehmen des Grundwasser, und die Reaktion der Felsenbelastung nach der Hitze von der Kernwüste. Für diesen Zwecke, die unterirdische Wegferfenfundgrube der Kernwüste wurde in der zwei und drei Dimensionen gesimuliert. Es beweist daß die Betonung wird zur thermisch Leitfähigkeit mangelnder Kontinuität und thermisch Konvektion des Grund-wasser sowie die thermisch Belastung ergezeugt durch die Kernwüste für den Entwurf und die Konstruktion des Fundgrubesystem gegeben werden, und sie müssen von den Feldmaße ergelangt werden .

Jan 1, 2003

1. Book reviews Phosphate rock, a bibliography of world resources. London, Mining Journal Books Limited, 1984. £10 (surface mail), £12.25 (airmail). Reviewer: P.Le. Grubb Ok Tedi, by William S. Pintz. London, Mining Journal Books Limited, 1984. 206 pp. £19 (surface mail), £22.25 (airmail). Reviewer: R.P. Plewman 2. Publications of the Canadian Mineral Policy Sector Lime by D.H. Stonehouse. 5 pp. Phosphates by G.S. Barry. 9 pp. Statistical summary of the mineral industry in Canada. 77 tables. Talc by M. Prud'homme. 6 pp. Zirconium by M.A. Boucher. 6 pp. Cement by D.H. Stonehouse. 13 pp. Gypsum and anhydrite by D.H. Stonehouse. 7 pp. Regional review by T.M. Buch. 12pp. SaltbyG.S. Barry. 7pp. Silicon, ferrosilicon and silicon carbide by D.G. Law-West. 6pp. SulphurbyB.W. Boyd. 9pp. Mineral Report 31. Canadian Minerals Yearbook 1981. Available from the above address at $40.75 per copy. 3. Mintek reports Report M18D The recovery of pyrite and gold from acid-leach residues from the Merriespruit Gold Mine. (First issued Feb. 1982; reissued Mar. 1984). Report M2OD The separation of ore from Cooke into high- and lowgrade fractions. (First issued Feb. 1982; reissued Mar. 1984). Report M33D Explanatory tests on the reduction of the sulphur content of sponge iron. (First issued Apr. 1982; reissued Mar. 1984). Report M43D Beneficiation tests on andalusite-bearing shales from a farm near Thabazimbi. (First issued Aug. 1982; reissuedMar. 1984). Report M129 The determination of tin, niobium, and tantalum in pegmatite by X-ray-fluorescence spectrometry. ReportM131 The determination of copper and nickel in iron- and chromium-bearing materials by a pressed-powder technique and X-ray-fluorescence spectrometry. Report M135 The installation of a 100 kV A plasma furnace at Mintek. The selection and installation of a 100 kV A a.c. plasma Report M136 The determination of gold in activated charcoal by use of a loose-powder technique and X-ray-fluorescence spectrometry. Report M140 The effect of physical and chemical factors on the corrosivity of a synthetic mine water.

Jan 1, 1984

By Dechun Lou, Benjamin Ravary, Merete Tangstad, Stein Wasbø, Sean Gaal

The melting phenomena of manganese ore, slag and alloys were studied in an experimental sessile drop furnace. Particles of approximately 20-60mg were placed on graphite substrates and then heated at a constant rate of 5°C/min up to 1830°C in a controlled gas atmosphere of Ar or CO. The shape of the particle was photographed with a digital video camera every second. It was observed that the melting behaviour can vary significantly, with some particles exhibiting a large softening/melting range. Selected samples were sectioned and then analysed with EPMA. The implications of the results on understanding industrial furnace operations are discussed.

Jan 1, 2007

By M. B. Díaz Aguado, I. Á. Fernández, C. González Nicieza, B. S. Menéndez

This paper summarizes the works that the Research “Group of Ground Engineering”, belonging to the Mining Department of the University of Oviedo, Spain, has been developing in close cooperation with the Regional Mining Department, since 2001, in order to control and monitor an experimental underground limestone exploitation by the room and pillars method. The aim of the current research is not only the geotechnical characterization of the rock mass (by means of laboratory and site tests) or the instrumentation of its displacements and stress changes (using convergence meters, INCREX probe, extensometers and rigid inclusion cells), but, moreover, to undertake intensive monitoring and control of such pilot mine, which is mined exclusively in order to accomplish this research. The data transmission was made on line via Internet, to achieve a full understanding of the behaviour of the experimental mine, to access data from remote locations and to visualize results from a website. All the collected information becomes input data for several numerical models using finite differences under a program developed in the research Group, ALMEC. The simulation and a final economical analysis lead to a design of an underground exploitation, at production scale, for a resource that is traditionally mined by means of open-pit process methods that could be worked underground with less environmental impact. The main purpose achieved by this exhaustive analysis is the technical and economic viability of such mine, for their optimisation for a future productive exploitation.

Jan 1, 2003

By B. J. Buys

Rock bolt integrity is a critical issue for the mining industry because of its influence on the safety of mining operations. Guided ultrasonic wave testing of the defects associated with resin-anchored rock bolts was investigated. Axisymmetrical and three-dimensional finite element models were built, one of a partially encapsulated bolt and the other of a bolt with a simulated local corrosion crack. Experimental bolts were then installed in a testing block and typical responses were compared to finite element models of different defect scenarios. Encouraging results were obtained for the smaller axisymmetrical and three-dimensional finite element models, as well as during the experimental investigation. It is recommended that software with energy-absorbing elements should be utilized to consider higher frequencies and longer bolts. Once the integrity of models such as these has been established, the models could in principle be used to train neural networks for use in commercial equipment to determine the integrity of the installed bolt.

Jan 1, 2009

Introducing your Council. Mr J. S. Freer, Pr. Eng., after matriculating at Michaelhouse in 1944, obtained a B.8c. degree in chemistry and biology (1948) and a B.Sc. (Hons.) in chemistry (1949) from the University of the Witwatersrand. Mr G. C. Thompson matriculated at Dale College in 1951. He then attended the University of the Witwatersrand, where he obtained a B.8c. (Min. Eng.) in 1959. Mr P. T. Fewell was born and educated in the United Kingdom. After obtaining the degree of Bachelor of Engineering (Mining) in 1958 at Sheffield University, he emigrated to South Africa. DtP. R. Jochens, Pr. Eng., has been a member of Council since 1974, serving as President in 1980-1981.

Jan 1, 1984