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There has been disappointingly little development in the analysis of rock slopes in open pit mines over the past 30 years. A brief review of literature shows that the application of numerical stress analysis methods to open pit mine slope stability has become only relatively common in recent times, and that there are as yet no standardized approaches. The lack of development in general, and of robust, standardized approaches in particular, is surprising in view of the ?ultra? deep open pit mines that are being developed to depths in excess of 1000 m. In this paper, the results of a substantial programme of two dimensional and axisymmetric analyses of open pit slopes are described. Variations in the following parameters were taken into account in this programme: slope angle, slope height and horizontal to vertical in situ stress ratio. The evaluation of the data has concentrated on the tensile stresses and the extension strains in the slopes. This is believed to be the first publication dealing with strain distributions in slopes. The occurrence of zones of tensile stress was very limited. These zones occur in the crests of slopes, except in the case of low horizontal to vertical stress ratios, in which case the tensile zone is in the floor of the pit. In contrast, very large zones of extension strain can occur, and this finding represents a significant new aspect in slope stability that has not been considered before. The greatest magnitudes of extension strain occur near the toe of the slope, either in the slope itself, or in the floor of the pit. The magnitudes of the strains are considered to be large enough to result in fracturing of intact rock, and the fracture orientations predicted are adverse for slope stability. The large zone in which such extension failure could potentially occur in a 1200 m deep pit is typically more than 100 m horizontally behind the toe and about 400 m up the face from the toe. Fracturing that is extension in nature is common in competent, brittle rocks and often develops with some violence and little or no warning. Such ?strain bursting? produces easily measurable seismicity, events often being audible as well. In the slope situation, the expected physical manifestation of this behaviour would be popping off of rock slabs and plates of rock from slope surfaces and popping up of the pit floor, as well as the formation of new fractures within the rock mass. Such behaviour may cause overall slope failure, or may initiate failure, which may then be driven to overall slope failure by other influencing factors or combinations of factors. In addition to instability resulting from the fracture surfaces themselves, all induced fracture surfaces could interact with natural geological structures to facilitate formation of a significant failure surface. With suitably orientated joints, extension strains are likely to manifest themselves in the opening up of such joints and hence in the loosening of the rock mass in a preferential orientation, with potential effects on groundwater flow patterns.

Jan 1, 2003

By Seksak Asavavisithchai, Natthida Jareankieathbovorn, Areeya Srichaiyaperk

"Recycling of ADC12 alloy scraps for fabrication of open-cell aluminium foams has been conducted via pressure infiltration method of replication process. The scrap, up to 50 wt.%, was melted with pure aluminium billet, followed by infiltration in a replicated mold of polyethylene foam structure. Compared with the pure aluminium foam, the compressive strength and hardness are higher for the foams with recycled scraps. The increase in foam mechanical properties is due to the presence of Si hard phase in Al matrix. The strength and hardness of the foams also increase with increasing contents of the scraps.IntroductionRecently, open-cell metallic foams have been brought to considerable attention of many industries due to their superior properties; such as large surface area, high specific strength, thermal conductivity, high service temperature and excellent anti-microbial activity, that cannot be found in conventional materials [1, 2]. Typically, open-cell foams are used in functional applications for which a requirement of high strength materials is not demanded. Good examples of such applications include heat exchangers, bone-replacement implants, interconnects, catalyst supports, and sound insulators.Among all types of open-cell metallic foams, aluminium (Al) is the most widely used base metal, due to low material cost, low density, low melting temperature and good corrosion resistance. To improve mechanical properties of Al foam, modification of foam microstructure with addition of alloy elements or ceramic particles is commonly carried out [3, 4]. ADC12 alloy is a typical die-casting Al alloy with high content of silicon (Si) close to the eutectic point in Al-Si binary phase diagram. The alloy is extensively used in the casting industry, due to high wear and corrosion resistance, low coefficient of thermal expansion and excellent castability [5]. The mechanical properties of Al-Si alloy are strongly dependent of Si content."

Jan 1, 2012

This paper discusses the prediction of subsidence over partial extraction systems in thick coal seams. A model based on empirical techniques using influence functions is developed to calculate the surface ground settlements above extraction panels. Independent of the influence function, two field parameters, the subsidence factor and the angle of draw (limit angle) are required to define the model. Both these parameters are best observed from critical or super critical subsidence areas. However in thick seams, extraction widths are typically sub critical and therefore it was necessary to refine an estimation process for sub critical conditions. Partial extraction systems in NZ are characterised by variability with respect to extraction thickness and depth. As extraction proceeds along a panel, conditions deteriorate once the critical span width is exceeded and therefore percentage extraction decreases. A further variable was introduced to the modelling which allows for varying extraction sequences. Two comparisons with field observations, one over a partial extraction panel, the other over abandoned workings, showed the method gave good agreement to measured subsidence values.

Jan 1, 2002

By C J. Kruger, E le Roux

Anglo American Platinum has adopted a strategy of Best Practice Principles (BPP) for sampling, mass measurement, analysis and metal accounting for more than a decade now. When new plants are designed, the most suitable sampling equipment and sampling protocols are implemented and material flows and plant layouts are designed around sampling strategies. A few years ago, a crushing plant for a high-grade matte stream was commissioned.The design called for the high-grade material to be crushed to 95 per cent passing 2 mm and the design allowed for a single cutter primary Vezin sampler, increments taken from a gravity flowing stream at regular intervals, whilst filling a tanker for the pneumatic offload at our base metal refinery. This was a single point of sampling and analysis that would measure the wanted output from our smelting complex and the input to our refineries. In addition, the design incorporated the functionality to collect increments in an ‘interleaved’ fashion from the Vezin sampler for internal precision checks.The metal accounting strategy for Anglo Platinum is the ongoing measurement of all inputs, outputs and stock levels for all our operations for platinum group metal (PGM) and base metal (BM) content. Included are yearly stocktakes, usually done on 1 February every year, across the smelters and refineries (at least the base metal refinery). A trend was developing in the accounting period immediately following the introduction of the new crushing and sampling facility, whereby the absolute difference between the physical stock and theoretical stock (PGMs predominantly) increased for the two respective sites on an ongoing basis. The smelter (sender) showed an increase in physical stock compared to the theoretical stock and the base metal refinery (receiver) showed that their theoretical stock increased against their physical stock. Because of this anomaly, an additional stocktake was held in September for the period in question and it was confirmed through the physical stock measurement results, that the PGM accounting problem was indeed pointing towards the evaluation of the high-grade matte stream.This paper showcases parts of the process that took place to explain the poor accountabilities for the respective sites. Previous results from the sampler ratification process (of the interleaved sampling design) were analysed again, a physical inspection was carried out on the sampling system again and the sampler performance was monitored (quality control parameters) for the period.From these investigations, it was found that airflows present inside the Vezin introduced the sampling bias and a change in sampling protocol was introduced as well as physical changes to the sampling equipment were made to eliminate the airflow and thus the bias conditions significantly. The accounting period which followed, after a phased upgrading process, showed that the accounting between our smelter and base metal refinery had been restored to within statistical limits (difference between physical and theoretical stock below five per cent relative to theoretical stock).CITATION:Kruger, C J and le Roux, E, 2017. Pitfalls in Vezin sampling for finely crushed materials, in Proceedings Eighth World Conference on Sampling and Blending , pp 151–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The Wainui Mill was conceived as a 60 - 90 t/d central mill to process gold ores of the Thames area of New Zealand from small mines in the district. The ores of the region exhibit various degrees of refractory response to conventional cyanidation leach due to the fineness of the gold, and association with pyrite. The alternative circuits involving cyanidation, flotation, and possible small-scale smelting are examined. The environmental impacts have been audited by the Commission for the Environment and were found to be acceptable.

Jan 1, 1986

By D. Parks, A. Miller, M. McNinch, R. Jacksha

Each year, hundreds of mine workers are involved in machinery-related accidents. Many of these accidents involve inadequate or improper use of lockout/tagout (LOTO) procedures. To mitigate the occurrence of these accidents, new safety methods are needed to monitor access to hazardous areas around operating machinery, improve documentation/monitoring of maintenance that requires shutdown of the machinery, and prevent unexpected startup or movement during machine maintenance activities. The National Institute for Occupational Safety and Health (NIOSH) is currently researching the application of Internet of Things (IoT) technologies to provide intelligent machine monitoring as part of a comprehensive LOTO program. This paper introduces NIOSH’s two phase implementation of an IoT-based intelligent machine monitoring system. Phase one is the installation of a proof-of-concept system at a concrete batch plant, while phase two involves scaling up the system to include additional sensors, more detailed safety/performance metrics, proximity detection, and predictive failure analysis.

Established as a Society February 26, 1957 OFFICERS AND COMMITTEES Wayne E Glenn, President Earl M Kipp, President-elect John S Bell, Past President R A Morse, Vice-President W D Owsley, Vice-President Everett G Trostel, Treasurer Joe B Alford, Executive Secretary 6300 North Central Expressway Dallas 6, Texas

Jan 1, 1960

RICHARD D. PICK RMCI PRESIDENT 2000-2001 on behalf of the RMCMI Board of Directors and Officers of The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 97th Regular Meeting and Convention to be held June 24 thru June 26, 2001 Steamboat Springs, Colorado

Jan 1, 2000

By Jamie N. Burdeski, Susan E. Hartfield-Wünsch

Aluminum sheet use has been steadily increasing in the automotive industry to achieve mass reduction and improve fuel economy. One significant manufacturing challenge for aluminum sheet implementation is the reduced formability compared to the steel alloys it replaces. This paper includes friction results from the draw bead simulator (DBS), twist compression (TCT) and strip draw (SDT) tests, for two oil based lubricants and four hot melt lubricants. Formability testing was done with the same lubricants and materials, testing in pure stretch with a hemispherical punch, and in draw with a breadpan shaped die.

Jan 1, 2015

By D Vidyarthi

Blasting is the most important activity in the mining industry, the world over. It is a well known fact that only part of the explosive energy gets utilized in causing the actual rock fragmentation. The rest of it gets converted into blast-induced ground vibrations and noise. Though blast vibrations cannot be totally eliminated, it is possible to minimize them by optimization of blast parameters. This paper highlights various in-house efforts put forth by the author towards site specific blast optimization and the monitoring of blast vibrations. It also deals with the prediction curves developed by regular regression analysis for the prediction of ‘blast vibrations’, ‘peak particle velocity’, ‘safe charge’ for various blasts.

Jan 1, 2007

"Pilot plants for pressure hydrometallurgy represent special design and project execution challenges. Over the past twenty years, Zeton has designed and fabricated a variety of world-class pressure hydrometallurgical pilot-plant facilities, and this paper discusses design considerations and strategies related to such projects. Project execution methods are also discussed, and guidance is given for the selection of materials of construction and for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical pilot equipment. The paper concludes with a discussion of the need for process similarity with future commercial operations and the realities of pilot-scale equipment.INTRODUCTIONThe process technology developer or owner and the designer/fabricator of a new pilot-plant facility are faced with some difficult technical choices even after the decision to build a dedicated plant has been taken. A pilot-plant project is usually on the critical path of a large commercial project involving investments many multiples greater than the capital cost of the pilot plant. Schedule savings in the design, manufacture, and commissioning of the pilot plant or in a rapid completion of the experimental program can be disproportionately beneficial to the overall development project. However, inappropriate shortcuts resulting in major oversights can be disproportionately problematic.A number of considerations and suggestions for both the project execution approach and the process engineering design of pressure hydrometallurgical pilot-plant facilities are presented as a guide for potential owners and operators of new pilot-plant equipment and facilities."

Jan 1, 2012

By M. W. Barger, J. K. H. Ma, J. Y. C. Ma, V. Castronova

The objective of this study was to investigate the effects of various bisbenzylisoquinoline (BBIQ) alkaloids on respiratory burst activity of alveolar macrophages and to characterize the interaction of these drugs with alveolar phagocytes. BBIQ alkaloids were chosen for study because they exhibit a wide range of antifibrotic potencies in a rat model, with tetrandrine being very effective and tubocurarine being ineffective. These drugs inhibited zymosan-stimulated oxygen consumption with a potency sequence of tetrandrine (IT) = fangchinoline (FA) > berbamine (BE) ., cepharanthine (CE) "" cycleanine (CY} ~ tubocurarine (TU). This inhibition of respiratory burst activity could not be attributed to a drug-induced decline in the ATP content of these pneumocytes. Drug binding to alveolar macrophages was directly dependent on temperature and drug concentration. The sequence for binding capacity was FA > TT = BE = CY > CE ~ TU. Therefore, there was no simple relationship between binding capacity and inhibitory potency. Binding capacity was not related to lipophilicity of these alkaloids. In addition, tetrandrine failed to bind to metabolically dead cells or sonicated macrophage preparations. These data suggest that the interaction of BBIQ alkaloids with phagocytes is not simply nonspecific binding to membrane lipids. Alteration of the cytoskeletal system with vinblastine, taxol, or cytochalasin B decreased tetrandrine binding by approximately 33% when adtkd separately and by 93% when added jointly. Pre-exposure of alveolar macrophages to stimulants increased the ability of BBIQ alkaloids to inhibit both oxygen consumption and superoxide release. These data suggest that the mechanism by which BBIQ alkaloids inhibit activation of phagocytes involves microtubules and bules and microfilaments. Pre-exposure of macrophages to stimulants would change the conformation of cytoskeletal components and may make these structures more susceptible to drug interaction.

Mar 1, 1992

By W. D. G. Hunter

Since 1945 the world's iron ore industry has experienced radical change. This transformation is reflected in new levels of production, consumption and trade, in shits in the location and size of markets, in the tapping of far distant sources of iron ore, and in the emergence of new export centres catering on an increasing scale to ore deficient, importing countries. Within the broad framework of shifting supply/demand relationships, certain operationally meaningful adjustments can be singled out for special mention: 1. The iron and steel industry has undergone vigorous and aggressive expansion, during the post-war period, not only in the capitalist world and among the socialist bloc, but in backward regions as well. New countries have been added to the list of steel producers, while new facilities have been relocated by established steel makers. 2. Overall demand for iron ore has risen rapidly, arid has flowed different channels.

Jan 1, 1964

By J. A. Rusnak, M. M. Gadde, S. S. Peng

In situ stresses are one of the key inputs to a successful underground excavation design. Because of the complex mechanisms involved in arriving at the current state of stress at a point in the Earth’s crust, often the only reliable way of estimating in situ stresses is by actual measurement. In the United States coal mines, overcoring relief method is by far the most popular technique used for estimating the virgin stress field. Typically, for stress measurement with overcoring, a vertical borehole is drilled into the roof or floor of an underground coal mine opening to a certain distance and change in borehole diameter is monitored at multiple points along the length of the hole when this borehole is overcored. For the measured stresses to represent the pre-mining stress field, the measurement points should be located beyond the influence zone of the mine opening. Actual data from several US coal mines have been collected to check if the measured stresses by overcoring represent true in situ stresses. The data indicate that most of the stress measurements were within the excavation influence zone. A three-dimensional numerical modeling methodology was applied to one of the collected cases to correct the measured stresses for the excavation influence. The modeling approach demonstrated the usefulness of integrating numerical modeling into a stress measurement program to estimate ‘true’ in situ stresses.

Jan 1, 2006

By T. Dlokweni

Several Rockmass classification systems have been developed and used in Civil Engineering design and for underground mining operations. Some of these rockmass classification systems have been modified and used in the South African coal mining industry to quantify descriptive geological information for use in coal mine design and roof support selection. The Coal Mine Roof Rating (CMRR) system developed in the USA has been investigated in detail as part of the study. Advantages and disadvantages of the system have been identified by means of underground and surface borehole testing. Investigations into the rating systems in South Africa found that most of the rating systems used in the South African coal mining industry are for planning purposes, and are conducted on borehole cores. This study also highlighted that the rating systems being used are based on geology, and that the human factor plays a major role in the rating systems. To overcome these problems, all the classification systems used in South African coal mines have been benchmarked against impact splitting technique and documented. The best elements of these systems are combined into a new standard system that will be easily used by all mine geologists and rock mechanics engineers. Plusieurs systèmes de classification de la masse rocheuse ont été développés et utilisés dans le Génie Civil et pour les opérations d'exploitation minière souterraine. Certains de ces systèmes de classification de la masse rocheuse ont été modifiés et utilisés dans l'industrie minière sud-africaine pour quantifier l'information géologique descriptive utilisée dans la conception de mines de charbon et la sélection de soutènement du toit. Le système d'Evaluation de Toit de Mine de Charbon (CMRR) développé aux USA a été examiné en détail, comme part de l'étude présente. Tests en surface de trous de mine ont permis d'identifier les avantages et inconvénients du système. Une étude des systèmes d'évaluation en Afrique du Sud a révélé que la plupart des systèmes d'évaluation utilisés dans l'industrie minière sud-africaine sont utilisés pour la planification, et sont menés sur les carottes de trous de mine. L'étude présente a aussi souligné que les systèmes d'évaluation utilisés sont basés sur la géologie, et que le facteur humain joue un rôle majeur dans les systèmes d'évaluation. Pour surmonter ces problèmes, tous les systèmes de classification utilisés en Afrique du Sud ont été référencés en termes de technique de fissuration sur choc, et documentés. Les meilleurs éléments de ces systèmes sont combinés dans un nouveau système standard qui sera utilisé aisément par tous les géologues de mine et les ingénieurs miniers. Verschiedene Gesteinsmassenklassifikationssysteme wurden entwickelt und kamen im Design für Hoch- und Tiefbau und Untertageabbau zum Einsatz. Einige dieser Gesteinsmassen-klassifikationssysteme wurden modifiziert und sind in der südafrikanischen Kohlebergbauindustrie in Verwendung, um beschreibende geologische Informationen für die Anwendung im Design von Kohlebergwerken und der Firstabstützungsauswahl quantitativ zu beschreiben. Das in den USA entwickelte Kohlengrubenfirstbewertungssystem (CMRR) wurde als Teil der Studie im Detail untersucht. Vorteile und Nachteile des Systems sind mittels der Untergrund- und Oberflächenbohrlochprüfung gekennzeichnet worden. Prüfungen der Bewertungssysteme in Südafrika ergaben, daß die meisten Bewertungssysteme die in der südafrikanischen Kohlebergbauindustrie benutzt werden, Planungszwecken dienen und werden anhand von Bohrlochkernen durchgeführt. Diese Studie hob auch hervor, daß die verwendeten Bewertungssysteme auf Geologie basieren und daß der menschliche Faktor eine Hauptrolle in den Bewertungssystemen spielt. Um diese Probleme zu überwinden, wurden alle in südafrikanischen Kohlengruben benutzte Klassifizierungssysteme vergleichsweise in Hinblick auf Spaltschlagtechnik überprüft und dokumentiert. Die besten Elemente dieser Systeme werden in ein neues Standardsystem kombiniert, das leicht von allen Grubengeologen und von Gebirgsmechanikingenieuren benutzt werden kann.

Jan 1, 2003

By D. J. Dodds, W. L. Schroeder

INTRODUCTION The plate loading test is a simple, useful tool in rock mechanics. The test consists of applying load to a rock surface and noting the resulting deflections. Plate loading tests are typically used to obtain modulus of deformation and related material properties, but can also provide information on blast damage and in situ stresses (1). Properties obtained are of course dependent on test procedure and test environment . In order to eliminate extraneous results it is essential that the interrelationship between the physical test environment and various rock properties obtained be thoroughly understood. Test interpretation is based upon elasticity methods, and the general assumptions made during analysis which include the following: 1. The rock is homogeneous, isotropic, elastic and continuous. 2. The stress is induced in a semi-infinite solid. 3. The plate is perfectly rigid or completely flexible. 4. Rock properties are independent of in situ stresses. 5. The plate and rock surface are smooth and parallel.

Jan 1, 1974

By Jim Owens

The methodology of quarrying changed significantly in the Indiana limestone industry in the 60 years between Sept. 11, 1941 and Sept. 11, 2001. The former was the date of the Pentagon groundbreaking ceremony, while the latter was when the building was damaged by American Airlines Flight 77. So too, though to a lesser degree, did the machinery and methods used to fabricate the stone. The rededication ceremony on Sept. 11, 2002 marked the end of the Phoenix Project, as the rebuilding effort was named. The story of this remarkable project illustrates what the American construction(and Indiana limestone) industry can accomplish when working toward a common goal.

Jan 1, 2005

By Varadarajan Seshadri

Geometallurgical characterization of iron ore which is a raw material for Iron making as in the case of charcoal blast furnaces operating in Brazil or for production of agglomerates such as iron ore sinter which serves as burden material for blast furnces of high productivity or pellets extensively used in the direct reduction processes all over the world in the iron and steel industry. Selection of proper raw material after due characterization should lead to an improvement of the productivity of the respective processes The usual classification of quality of iron ore is uniquely based on chemical analysis, granulometric and physical parameters. However not much emphasis has been given to the structural characteristics which also are important in the processes. Different typological categories of Brazilian iron ores have been used in the characterization . For instance, several kinds of hematite crystals like specularite, martite and microgranular hematite, etc with variable crystal sizes are found in the different ore types. They are also composed of different of fabrics and types of accessorial mineralogical constituents and have different porosities, pore diameters, etc which influence the cold and the hot agglomeration stages of the ore fines, and also chracteristics such as reducibility, decrepitation etc, important for assessment of quality of iron ores. . The first step for attaining a good characterization of ores is to know in detail about the structure of the deposit, shape of the body, types of iron ores and their distribution. This requires a geological-structural study and the mapping of the bodies using mineralogical criteria for typological classification of ores. followed by structural characterization of materials in stages of mining, comminution, screening and concentration processes. In this contribution a geometallurgical approach for quality control of Brazilian iron ores for sintering and pelletizing processes is highligted.

Jan 1, 2006

By D. Grabowski, Z. Pokryszka

ABSTRACT: Some residential areas of the iron basin of Lorraine (in the North-East of France) are affected by noxious gas emissions (under oxygenated, carbon dioxide loaded and radon loaded gas mixtures). Site investigations showed that the gas flow was mainly due to natural thermal air circulation between old mines and the external atmosphere. The main hazards associated with this flow of gas and its potential accumulation in confined volumes within buildings are asphyxiation and intoxication. A further study is in progress in order to better understand the origin of the gas generation within the old iron mine workings. Following the first hypothesis, the carbon dioxide emission is mainly due to the specific hydro-geo-chemical process associating the pyrite oxidation with the acid dissolution of carbonates. KEY-WORDS : gas, emission, mine, flow, pyrite. ZUSAMMENFASSUNG: Einige Wohngebiete der Eisenmulde Lothringen (im Nordöst Frankreich) werden von Ausgasung gesundsheitsschädlichen sauerstoffarmen Mischungen, die mit Kohlendioxid und Radon beladen sind, betroffen. Untersuchungen am Ort haben gezeigt, wie diese Gasstroemung von natürlichem thermischen Luftumlauf zwischen den alten Bergwerken und der externen Atmosphäre ausgelöst wird. Erstickung und Vergiftung sind die wichtigste Risiken, die mit dieser Gasströmung und ihrer möglichen Speicherung in begrenzten Lokalen zusammenhängen. Eine weitere Untersuchung wird durchgefuehrt so dass man die Herkunft der Gaserzeugung in den alten Grubenräume besser versteht. Der ersten Hypothese folgend, Ausgasung von Kohlensäure liegt vor allem an dem hydro-geo-chemischen Prozess, der Pyritrösten mit der säuren Auflösung von Karbonate verbindet SCHLÜSSELWÖRTER: Gas, Ausgasung, Bergwerk, Strömung, Pyrit RESUME: Certaines agglomérations du bassin ferrifère lorrain (au Nord-Est de la France) sont affectées par des émanations de mélanges gazeux sous-oxygénés et chargés en certains gaz nocifs (dioxyde de carbone, radon…). Les investigations effectuées in situ ont montré que les écoulements gazeux à l’origine de ces émanations sont liées au phénomène de tirage naturel entre les anciens travaux miniers et la surface. Les principaux risques engendrés par ces émanations de gaz et son accumulation possible dans des endroits confinés sont l’asphyxie et l’intoxication. Une étude est en cours afin d’expliquer l’origine de la modification de l’air au sein des vieux travaux miniers. Les émissions de dioxyde de carbone seraient dues à des processus hydro-geo-chimiques associant l’oxydation de la pyrite et la dissolution de carbonates. MOTS CLES: gaz, émanation, mine, écoulement, pyrite.

Jan 1, 2003

The range of environments which control the level of ground support required vary greatly in terms of rock type, rock structure and the mining method used. At the operating mines visited during this review the level of ground support was such that incidence of rock-fall- related accidents were rare. It was also found that methods existed to support most of the conditions encountered. The main problem areas were weak rock, major geological structures, areas of heavy jointing, high development density and areas affected by high mining-induced stresses and blasting. With stope support the level of success was much lower than that achieved in development; the larger spans and more rapid changes in geometry of open stopes compared with cut and fill stoping (where cables were originally used) led to significant problems. Before a useable design method for cable support of stope walls and pillars can be obtained the precise failure mode of the walls and pillars, and the interaction of the support and the rock mass must be investigated.

Jan 1, 1982