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By J Czerwinski, M Kasper, M Wyser, N Heeb

The VERT project 1993 - 1998 laid the technical foundation for curtailing the emission of fine particles from diesel engines at Swiss underground workplaces. The targeted maximum was 100 ¦g/m3 EC. Extensive laboratory and field investigations demonstrated that this specification is only attainable with modern diesel particulate filter (DPF) systems that almost eliminate particles in the entire lung penetrating size range from 20 nm to 2.5 ¦m. In January 2000, Switzerland mandated compulsory particle filters in underground workplaces, particularly in tunnelling, irrespective of engine age, size and type. After the implementation, the particle concentration in the respiratory air was below 40 ¦g/m3 EC, compared to earlier values of up to 750 ¦g/m3 EC. Deployed DPFs have proven filtration rates of 99 per cent in the entire size range of alveoli intruding particles. The DPFs are as durable as the engine, suffer no ageing and require minimal maintenance. The failure rate is below three per cent annually. Of the 6000 retrofitted construction machines in Switzerland, about 400 are deployed underground. Prerequisites for this quality are a sophisticated certification procedure, electronic monitoring of DPF operation and meticulous periodic exhaust gas inspection of the engines.

Jan 1, 2005

By Martin Wacker

Cameco Corporation, on behalf of a joint venture, is preparing surface and underground facilities at their northern Saskatchewan property in preparation for the future operation of a high-grade uranium mine. The Cigar Lake orebody is situated about 430 metres below surface at the unconformity between metamorphic basement rocks and flat lying sandstone. Major technical factors influencing the mining method selection include ground stability, control of ground water, radiation exposure and ore handling and storage. A decade-long test mine program resulted in the selection and validation of ?jet boring? a non-entry mining method. Cigar Lake?s jet boring mining method involves several major steps; artificial ground freezing of the orebody and surrounding rock, TBM (tunnel boring) type development of access crosscuts below the orebody, installation of cased pilot holes upwards through the ore, and ore extraction using a rotating high pressure water jet within the pilot holes. The resulting cavities are surveyed and backfilled with concrete. The ore slurry will be processed underground and pumped to surface. This paper discusses the jet boring mining method in general terms and includes highlights of the Cigar Lake test mine program completed in 2000.

Apr 1, 2005

In 1972, with the West Lyell Open Pit winding down, mining operations transferred underground. All development tunnelling until the end of the decade was carried out by a fleet of ten pneumatic Jumbos.A decision was made in 1980 to purchase an electric-hydraulic Jumbo and a second was purchased in 1982. Their introduction changed the face of development at Mount Lyell. Significant new demands were placed on main-tenance sections, particularly on electrical reticulation.Subsequently, two further electric-hydraulic Jumbos were purchased from Agnew Mining in 1984, and successfully overhauled and commissioned. As well, two electric-nydraulic production drilling rigs have been purchased. Only one of the original pneumatic Jumbos remains in service.

Jan 1, 1985

By E. Gybbon Spilsbury

It is not my purpose in this paper to describe all the different contrivances which have been devised, during the last quarter of a century, for the purpose of Iessening the expense of mining and tunnelling operations; I wish merely to call your attention to the crying want of the Western miners for some cheap and effective machine, capable of economizing on the heavy item of hand-drilling, and to enumerate a few of the latest improvements which have been made in machines of this class. This necessity for the introduction of some kind of labor-saving machinery in mining, especially in the West, begins to make itself felt more imperatively every day. No branch of industry has remained so conservative to the old customs and systems of working, as has mining; and yet no branch is so entirely dependent on economical working for a successful issue; and in very few is the proportion of cost of hand-labor to profits obtained so preponderantly heavy. Perhaps the chief reason for this seeming apathy towards progress in this direction arises from the fact that nearly all mining operations, especially in this country, are carried on in regions more or less remote from the great centres of civilization, thereby rendering the carriage and erection of machinery extremely difficult and expensive. Another reason, however, exists in the fact that a large number of men in charge of mining operations are greatly prejudiced against the introduction of machinery underground, from the idea that it cannot be made to adapt itself to the various positions and

By B. Ladanyi, B. Hoyaux

One of the most important problems in underground works is the assessment of the stability of underground openings and the determination of loads on eventual supporting structures. Under certain stress conditions, a hard and sound rock around an unlined opening may show a tendency to rock bursting, which can be prevented by appropriate measures. On the other hand, a less competent rock even if it fails in a less violent manner may give rise to a rock load because within limited regions surrounding the opening, the failed material may have a tendency to flow into the opening; this condition should be prevented by designing a proper supporting structure. The stability of the opening, as well as the value of the design loads acting on the supports in the latter case, depends clearly on the shape, extent, and location of the failed regions, which are often called “plastic zones.” It has been known for some time how the plastic zones develop in some very simple cases, such as in the case of a circular opening in an elastic ideally plastic medium subjected to a nongravitational stress fie1d.l However, to the knowledge of the authors, no information has been available up to now about the extent of the plastic zones in a more general case and for rocklike media. ASSUMPTIONS ON ROCK BEHAVIOR MADE IN THE CALCULATION The solution shown in this chapter is valid for a horizontal tunnel of circular cross section driven through a rock medium at a finite depth.

Jan 1, 1970

By H. A. D. Kirsten

The structural competence of mesh- and fibre-reinforced shotcrete was investigated in two series of tests on full-scale panels. It was found that uniformly distributed loading was marginally less demanding than point loading, mesh reinforcement was superior to fibre reinforcement, Dramix fibre and Melt Extract fibre were similar in reinforcing characteristics, and 30 mm to 35 mm was an optimum fibre length. Furthermore, the consistency of the fibre content could not be assured on practical mining sites, and an average fibre content of about 1,5 per cent was the maximum that could be obtained for fibre lengths not exceeding 35 mm. Also, owing to its greater flexibility, shotcrete reinforced with diamond mesh was preferable to fibre-reinforced shotcrete in mining excavations subject to squeezing conditions. In view of the difficulties associated with assuring the consistency of the fibre content in mining applications, it appears that the sophisticated attributes of fibre-reinforced shotcrete can be effectively exploited only in civil-engineering applications in which quality assurance is subject to explicit contractual control. Load-deflection curves, together with measurements of compressive stresses in the surfaces of some of the panels, enabled the ultimate flexural strength of reinforced shotcrete to be rigorously formulated, and rigorous design procedures for shotcrete subject to bending and direct thrust to be developed. The application of the procedures is demonstrated in a practical design case in which the moments and thrusts in a tunnel lining are determined in a numerical analysis of the interaction between the lining, the surrounding rock, and the rock-reinforcing system.

Jan 1, 1992

By Richard P. Curtin, Madan M. Singh, Francis S. Kendorski

INTRODUCTION The use of roof and rock bolts to reinforce the strata is an established method of rock support in both underground and surface excavations. However, the need to drill a hole, extract the drill-rods, and then place the bolt is time-consuming and costly. This becomes even more significant if the bolting is repetitive and extensive as in coal mining. Though the main thrust of this development was directed towards coal mining, the basic concepts are also widely applicable to all excavations. The authors, therefore, feel that this innovation should be of interest in rapid excavation and in tunneling. In the case of coal mining, it has been established from past statistics that the roof-bolting operation is the most hazardous activity. This is primarily because of the operator being exposed to unsupported ground. It is evident that remote installation of roof bolts would markedly improve the safety of the operation, if accomplished more readily with self-drilling bolts rather than the conventional two-step variety operation. Thus, in addition to increasing productivity, this development can be considered to be a milestone towards further improvements. The objective of this program was to establish the technical and economic feasibility of self-drilling roof bolts for use in coal mines. It might be clarified at the outset that this work was, therefore, directed primarily at showing that workable self-drilling bolts with less cost can be developed, which could be effectively used in mines. It was not to fabricate a production model bolt.

Jan 1, 1979

By C. E. Wethered

THE Morning mine is operated through one main working adit, known as No. 6 or 800 tunnel level. At a distance of 10,000 ft. underground from the portal is the vertical four-compartment, main working shaft, which extends to the 3050 level, a distance of 2250 ft. below the collar, or 800 level. Shaft-stations are cut and levels opened every 200 ft. of depth and the ore is stoped to the next level above. The vein is nearly vertical and the ore is usually fairly massive and brittle. Both walls are soft and slabby and much difficulty is therefore experienced in holding them. Stopes are usually carried up in short sections, approximately 200 ft. in length, that are mined as rapidly as possible in order to avoid a too great replacement or repair of stope timbers. The four-compartment vertical shaft, 110 ft. in the footwall of the vein, is the sole medium of outlet for all ore mined below the adit level. Two compartments of this shaft are used exclusively for hoisting ore, except at the time of changing shifts, when one compartment is used to handle some of the men and timber. The third compartment is equipped for handling men, tim-ber and all general supplies and is operated by a Nord-berg 300-hp. electric hoist. This hoist has a lifting ca-pacity of 14,000 lb. with an average rope speed of 800 ft. per minute. The fourth compartment is used solely as a manway and pipeway.

Jan 7, 1927

By Ian M. Loomis, Malcolm J. McPherson

A fuel-rich fire exists when the quantity of fuel exceeds the oxygen available to support complete combustion. The transition of a mine fire from Oxygen- rich to Fuel-rich combustion, at this time, represents a point-of-no-return in the fire fighting efforts. Once the transition has been made to fuel-rich the fire can spread at a rate 6 to 10 times as fast as in the oxygen-rich state. Utilizing available technology the fire fighters are left to seal the fuel-rich fie as the only technique to extinguish it. In order to minimize the devastating effects of a fuel- rich fire it is important to understand the means by which the fire becomes fuel-rich and by what means the fire may be returned to an oxygen-rich state. This paper covers: the development mechanism of a fuel- rich fire in a coal mine entry and the physical and chemical effects of applying water to a fire. Experiments concerning these matters have been conducted in a 30 cm square wind tunnel constructed at the Virginia Polytechnic Institute and State University as a model coal mine entry. This paper also addresses the results obtained in testing application of a water mist to fuel-rich fires in this model. These tests have centered on the development profile of a fuel-rich fire in a duct and demonstrate a means of regaining control of a fuel-rich fire by returning it to an oxygen-rich state.

Jan 1, 1995

By F. B. Speaker

MUCH of White Pine's success is due to the mechanization of mining operations and the development of an efficient beneficiation process to extract usable copper from the low-grade ore (averaging slightly more than 1 pct copper content). When the mine was first opened, all ore was trucked to a conveyor system installed in the slope leading out of the mine. But as new mining areas have been opened up at increasing distances from the slope, conveyors have replaced the trucks for much of the haulage. This conveyor program is expected to continue as mining progresses. Here is how the present underground system functions: Run-of-mine ore is dumped into two truck hoppers and withdrawn from the bottom of each hopper by a 60-in. apron feeder 22 ft long (see diagram). Collecting conveyors 54 in. wide and 44 ft long receive the material from the apron feeders and discharge to two main-line 54-in. conveyors, one 2000 ft and the other 2600 ft long. Operating at 312 fpm and handling 1200 tph, the main-line conveyors converge near the bottom of the tunnel leading out of the mine and discharge into two 72x168-in. Vibrex screens. Ore under 8 in. goes directly to the bin beneath. The oversize is fed to two 32x40-in. jaw crushers and after crushing joins the 8-in. material in the bin.

Jan 12, 1957

By J. W. Thompson

BURYING DEAD MINERS. BURYING BODIES OF DEAD MINERS. REVISED STATUTES (HURD) 1874, P. 263. SEC. 22. LIABILITY OF RAILROADS, ETC., FOR BURIAL EXPENSES.-When any railroad company, stage or any steamboat, propeller, or other vessel engaged in whole or in part in carrying passengers for hire, brings the dead body of any person into this State, or any person dies upon any railroad car or in such stage, steamboat, propeller or other vessel in this State, or any person is killed by cars, or machinery of any railroad company or by accident thereto or by accident to or upon any such stage, steamboat, propeller, or other vessel, or by accident to or in or about any mine, mill or manufactory,* the company or person owning or operating such cars, inachinery, stage, steamboat, propeller, or other vessel, mine, mill or manufactory shall be liable to pay the expenses of the coroner's inquest upon and burial of the deceased and the same may be recovered in the name of the County in any court of competent Jurisdiction. NOTE--The original Act of February 15, 1855 (Laws 1855, p. 170), makes no reference to the dead bodies of persons killed" by accident to, in or about any mine."

Jan 1, 1919

By Frank Firmstone

. In the early decades of the past century the method of starting iron blast-furnaces by " scatlolding-down" seems to have been in universal use for coke-furnaces and, at least in this country, for charcoal-furnaces also. It was likewise used at some of the early anthracite-furnaces, as is stated in the important " Reminiscences" printed by the late Samuel Thomas.' It had been generally superseded in Great Britain as early as 1850, by some variations of the plan now used, and was rarely used when Percy wrote.2 On the Continent it was still followed ill the 60's; and was elaborately described by Valerius in 1852. I have never read any statement as to when and by whom " scaffolding " was first dispensed with, but the following extracts from journals of my father seem to fix an authentic date for an instance in this country: " [Pittsburg] July 12, 1838.—Went with Major Wade to his foundry,etc., and he gave me a letter to D. Tyler, Esq., Farrandsville, Agent Boston Coke & Iron Co." " [Lockhaven, Pa.] July 18, 1838.—Heard there was a flat-boat going to take some gentlemen up to Farrandsville. Got on boat and to Farrandsville, 5 or 6 miles, in 1 hr. 30 min. Dined, and then delivered my letter to Ma Tyler, who showed me much attention, and everything belonging to the furnace, and had the water turned on the wheel that I might see the blowing-cylinders at work. There are two cylinders, 6-ft. stroke, -56 in. in diameter, but they find that one makes more than enough blast for the furnace. The furnace has 16-ft. boshes, 7-ft. tunnel-head, and is 47 ft. high, 3 tuyeres, and 3 heating-ovens [hot blast-ovens]. A

Jan 1, 1908

By J. A. Voster

Premier Mine (a part of De Beers Consolidated Mines Ltd) which is situated 38 km to the east of Pretoria, has the largest known diamond pipe in South Africa. The mine started operations in1903. The Premier Mine kimberlite pipe is unique in that it is intersected by a 75 m thick gabbro sill at a depth of 400 m below surface. The current mining method used is mechanized panel retreat caving, which has been successfully used to extract ore from the different mining blocks. All caving at Premier Mine is below the sill and failure to exercise good draw control could cause the early ingress of gabbro waste. Draw control at Premier Mine is crucial as it aids in preventing conditions of isolated draw, which results in the early ingress of waste, compaction of the kimberlite and the loss of ore reserves. To assist, an underground vehicle monitoring and control (VMAC) system was installed to enable the effective management of the draw control function. The system has evolved graduallyin collaboration with a local developer. The data accumulated is used to decide the most effectivedraw point loading pattern in order to achieve sound draw control principles. This is achieved as each load can be related back to the draw point of origin. The VMAC data recorded also relates back to specific load-haul-dumps (LHDs), tunnels, ore passes, as well as indications of dates, times and payloads recorded. An interface exists between the VMAC and a draw control linear program. Premier Mine’s VMAC system is not a ‘dispatch’ system but rather a draw control system that caters for Premier Mine’s specific block cave requirements. Premier Mine has realized that successful automation is not dependent on technology alone but rather on the successful implementation thereof.

Sep 1, 2001

By Richard L. Daley

Today's subject of discussion, "OSHA AND ITS PROBLEMS", must be covered in the time allotted with a slight tongue in cheek approach, for if one is to believe that the "problems of OSHA" can be covered in a twenty minute review, he, himself, has one of three problems: 1. He has residual combat fatigue left over from World War II. 2. He is an egomaniac. 3. He is afflicted with both of the above. Clearly, the difference between divinity and humanity lies in their work. All human endeavor is plagued by errors and omissions, and unless one would be so facetious as to equate bureaucracy with godliness, our government-sponsored ventures seem to receive more than their share of missive missles with which to combat the ills of our society. Coming from an industry known for its undertaking of gargantuan projects, I feel capable of looking at things from the big picture perspective. No one would deny that the massive influx of government, both in the monetary and supportive personnel roles, has accomplished much. But only we, as tunnel constructors, have moved countless mountains of muck, placed endless yards of concrete and engaged the public on numerous fronts and in spite of all, at times have even made a profit! Profit! What a dirty word in our society today. It makes one shrink back from the filthy overtones dripping with the cloying scent of decay. Never shall we judge the success of our government programs with such a slimy yardstick as profit. No, for that which has been conceived in the bowers of Camelot, the measure must be more elevating and inspiring. Something to bring a proud bearing to our efforts! Nothing has helped to alleviate the suffering of man as much as medicine. The eradication of typhoid, polio, and

Jan 1, 1979

By 000-001-568

August 15th, 1871. THE Institute assembled in Packer Hall of the Lehigh University, the President, Mr. David Thomas, of Catasauqua in the chair. Professor Henry Coppée, President of the Lehigh University, made an address of welcome to the Institute, and placed at its disposal a convenient hall for purposes of meeting. Mr. Thomas tendered his resignation as President of the Institute, as advancing years prevented him from actively participating in its meetings. The Institute declined to accept the resignation, and, on the assurance that active duties would not be expected of him, Mr. Thomas was induced to withdraw it. Invitations were received from Mr. B. C. Webster, President of the Lehigh Zinc Company, to visit the mines and works of the company; from Mr. Charles Brodhead, to visit the Chapman Slate Quarries ; and from the Lehigh Coal and Navigation Company, to visit their works at Summit Hill and Mauch Chunk and the Nesquehoning Tunnel. The Council reported the names of persons already elected in the two classes of members and associates. The following resolutions were passed: Resolved, That a committee of three be appointed, who shall take into consideration the printing and publishing of papers originating with the Institute, and that a uniform system as regards size and execution be adopted. The committee appointed consisted of Messrs. R. W. Raymond, E. B. Coxe, and the Secretary. Resolved, That the Council design and prepare a seal for the Institute at the earliest practicable time. Resolved, That a committee of six, with power to add to its numbers, be appointed to examine into the question of the more economical production of iron in this country. The committee appointed consisted of Messrs. G. W. Maynard,

Jan 1, 1873

By G Gibson

Realising that current roadway development performance levels were unlikely to sustain new generation high-capacity (15 Mt/a) longwall mines then being planned, the Australian Coal Association Research Program (ACARP) established a Roadway Development Task Group (RDTG) in 2005 to develop a research strategy targeted at improving roadway development performance in Australian longwall mines. The initial phase of the project identified a number of factors that differentiated best practice mines from others, and proposed a multi-faceted research strategy encompassing both short- and long-term research initiatives, including:conducting regular benchmarking studies across the industry to identify factors contributing to improved performance and to monitor performance trends,conducting regular industry roadway development operatorsÆ workshops to facilitate the transfer of successful roadway development improvement initiatives throughout the industry and facilitate networking between development practitioners,development of alternative skin reinforcement and containment measures that would eliminate the use of steel mesh and enable face support systems to be fully automated,development of automated bolting and mesh handling systems that would enable operators to be removed from the immediate face area,development of a body of knowledge of industry roadway development practice,development of a web-based information management system to capture and transfer emerging developments in roadway development practice and technology,reviewing the Australian civil tunnelling and underground metalliferous mining sectors to identify practices and technologies that could potentially be utilised to improve roadway development performance, anddeveloping a new generation high-capacity mining system capable of +10 metres per operating hour for 20 or more hours per day (CM2010). The paper reports on the progress of the above initiatives and outlines strategies to continue the pursuit for improved roadway development performance.

Jan 1, 2008

By James J. Olson

INTRODUCTION The need for Government-sponsored research and development to increase excavation rates and lower costs for tunneling and mining operations in a variety of rock types has been emphasized in a wide range of publications from advisory panels, symposiums on rapid excavation, and individuals. In response to the predicted demands for mining and construction-oriented underground excavations for the next two decades (1970-1989), a comprehensive 10-year, $200-million research program in rapid excavation was proposed by the National Academy of Sciences in 1968 (1). Although the large program recommended by the Academy has not been funded, substantial Government-sponsored research in rapid excavation has been conducted during the past several years. This paper reviews some of the significant research accomplishments obtained under a three-year, $6.6-million research program in rock mechanics and rapid excavation sponsored by the Defense Department's Advanced Research Projects Agency (ARPA) and managed by the Bureau of Mines. In addition to the rock mechanics research, five major phases of excavation; systems analysis, geologic prediction, rock disintegration, ground support, and materials handling were represented by the projects funded under the ARPA program. The brief outline below recapitulates the major research areas and some of the projects summarized by this paper: Excavation Process Modeling by Computer Geologic Prediction Geologic Reconnaissance for Site Selection Longhole Probe Drilling for Hazard Detection

Jan 1, 1974

By E. G. Leonardon

THE object of this paper is to describe briefly the practical results obtained in several problems of civil engineering by resistivity measurements of the underground. It is intended for the mining engineer, as well as for the construction engineer; the stratigraphical problems discussed are general and frequently are encountered in mining exploration. Resistivity measurements have been used in mining and oil exploration for a number of years.1 Their introduction in the field of civil engineering, on the contrary, is rather recent. It was applied for the first time in the spring of 1928 near Littleton, N. H., in the survey of two dam sites for the New England Power Assn .2 Since then, the geophysical firm with which the author is connected has had an opportunity to develop this field of activity, and more than 20 investigations at dam and tunnel sites have been carried out in the United States and Canada. A part of this work has been verified by underground or drilling exploration. This paper deals with but a few of the results, which we are permitted to make public now. The theoretical and technical sides of the processes employed will not be discussed; they have already been described in various technical. .publications. A few general points will be mentioned, to make clear the practical examples given.

Jan 1, 1931

By William Plank

In practically all rock-excavation problems there is need for a careful study of the rock structure, its fault, cleavage or bedding planes, and even the texture of the rock itself. These studies should form the bases upon which an excavation method is selected and they should be carefully considered in predicting the amount and extent of the excavation. The need for such studies was forcibly illustrated in the problems involved in a cut made in 1929, along and underneath a 200-ft. high rock projection for a State-highway near the City of Easton, Pennsylvania. The rock mass was badly faulted and also contained a number of cleavage planes at approximately right angles to the fault planes. Much of this structure was visible and could have been studied and analyzed before' the work was begun. The State had rigid specifications as to finished grade and slope of cut, which apparently were made without reference to the geologic structure. The contractor complied with the specifications, under the close inspection of the State engineers. A tunnel blast was, placed in the base of the cliff, with the result that 65 per cent more rock was broken than was intended by the specifications. About four years after the blast, the writers of this paper studied the circumstances surrounding the operation, to determine the cause of this excess excavation.

Jan 1, 1935

By Ingvar Janelid

DURING the last ten years, in the effort to save manpower and costs, methods of drilling and blasting in Sweden have changed and developed in a revolutionary manner. These developments have been accompanied by extensive alterations in methods of tunneling and in mining technique. Since the end of the 1940's there has been a 100 pct change-over in Sweden to the use of tungsten carbide tipped drill steel. Both investigations and practical results have shown clearly that a tungsten carbide chisel bit fastened directly on the drill steel is the most economical for Swedish conditions. This applies to drill steel up to the longest size it is practical to handle. In terms of drilling footage, durability of the drill steel and the tungsten carbide bit is generally the same. In this respect, therefore, a detachable bit offers no advantage over integral steel. Transportation of integral steel to the grinding plant, instead of detachable bits only, involves heavier work, but this is counteracted by placing grinding plants closer together or by grinding at the working place itself. The drilling rate with integral steel is higher, the trouble of changing bits is avoided, and the difficulties which always arise with joints are eliminated.

Jan 6, 1954