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By ROLLIN THOMAS CHAMBERLIN

The studies herein reported were begun as a part of researches undertaken by the United States Geologü;al Survey looking to the more effcient utilization of the coal in the United States through the reduction of waste in its extnidion, and were continued as part of further researches having regard to the conservation of the fuel resources of this country and to the lessening of injuries and fatalities in coal mining. Among other phases of the general problem to be studied were the origin of the gas whidi escapes into coal mines, its modes of occurrence in the coal and rock strata, and the conditions governing its outflow into the mines. The subject of relative danger from destructive explosions due to gas and coal dust in different mines belonging to different coal fields was to be one of the principal lines of investigation. But this work was barely under way when the series of unusually disastrous explosions in the Naomi, .Monongah, and Darr mines of Pennsylvania and West Virginia, in December, 1907, afforded an exceptional occasion to observe the behavior of explosions on a large scale. Because of the opportunities for study afforded by these terrific explosions, the inquiry originally planned was d ¡verted to the more specific investigation of the conditions in tl10SC mines, and the examinations have been directed toward finding those qualities of gas and dust which were concerned in these explosions. The following discussion, therefore, consists essentially of a report on that subject; but it is far from being exhaustive, and is to be regarded as a preliminary outline of investigations which are still in progress. The first of the three mine explosions mentioned occurred in the Naomi mine of the United Coal Company, near Bellevernon, Pa., on Sunday, December 1, at 7.40 p. m. All the men who were within the mine at the time, fortunately only 34, were killed. Less than a week later there occurred in mines Nos. fì and 8 of the Fairmont Coal Company at Monongah, W. Va., the most disastrous mine explosion yet recorded in the annals of American mining. The mines were comparatively new and well laid out. Mine No.8 had been in operation only about two years and was the pride of the Fairmont Coal Company. Mine No.6 was first opened ahout four years earlier. In order to make it possible, in case of emergency, for either mine to be ventilated by the ventilating system of the other, the two sets of workings were connected underground. The F face heading of mine K o. 6 led direetly into No.2 north heading of No.8 mine. On Friday, Dcccmber 6, at about 10.30 in the morning, an explosion of unusual violcnce swept completely through both mines, pursuing its course throughout the numerous ramifications and bursting out of the two pit mouths, located It miles apart, nearly simultaneously. The slope of mine No.6 was only slightly damaged, but at the mouth of No.8 the destruction was very great. The fan was wrecked, the engine house was demolished, and mine timbers were blown across Monongahela River: As nearly as can be determined, 361 men were killed in the two mines by the explosion. .While the inspection of the Monongah mines was still in progress, on Thursday morning, December 19, at about 11.20, a similar explosion wrecked the Darr mine of the Pittsburgh Coal Company ut Jacobs Creek, Pu.; 238 men lost their lives in this explosion, which in number of casualties is second only to the :Monongah disustcr in the history of American mining. Of ull thc men in the mine at the , time of the explosion, only one mun, who happened to be within 100 feet of the ~iUrface on an old manway in a wet, unexploded portion of the mine, succeeded in escaping alive. The underground investigation of these mines was made in cooperation with Clarence Hall and ""Valter O. Snelling, of the United States Geological Survey, and James ""V. Paul, now of the Survey but at that time chief of the department of mines for vVest Virginia, to all of whom the author is greatly indebted for valuable assistance, suggestions, and advice. Mr. Paul will rcport on the nature of these explosions, the precipitating causes, their destructiveness, and the general cüliditions in these mines following the disasters. The present report is confined essentially to the laboratory examination of some of the explosive materials collected from these mines directly ufter the explosions.

Jan 1, 1911

By Arturo Ressi di Cervia

The utilization of diaphragm wall construction in Hong Kong began in 1974 with the construction of the New World Center, the first diaphragm wall job built in the British Colony. That landmark job of which I am presenting a few slides and a schematic description, embodied all of the difficulties and problems which are encountered in the difficult geology of Hong Kong. A small rocky island in the South China Sea, Hong Kong provides one of the finest natural harbors in the world. It is its splendid harbor, coupled with the enterprising attitude of the Hong Kong Chinese and the laissez-fair attitude of the British government which has resulted in the explosive growth of this speck of land soon to revert to the political control of mainland China.

Jan 1, 1993

By H. Mori

The session chairman, Dr. H. Mori, welcomed the delegates to Discussion Session 8. AUTHORS PRESENTATIONS 1 . G. Price, Building Research Establishment. UK Mr. Price expanded on the content of his paper and presented elements of various case histories of bored piles instrumented by the Building Research Establishment. In particular, the interpretation of data from instrumented piles is critically related to: (i) the construction process (ii) concrete stiffness and variability (iii) the effects on the pile due to installing instruments The main role of the instrumentation in the examples presented was to establish pile performance under service loading conditions. Of particular interest is the mobilisation of skin friction and soil shear modulus.

Jan 1, 1991

By A. R. Gaba

Phase I of the Canary Wharf development in London's docklands involves the construction of six fifteen storey buildings located predominantly over water of the West India Docks. The buildings are supported on some 1000 No., 25m long, open ended steel tubular piles driven through 10m of dock water to found in dense sand at a depth of about 15m below dock bed level. The piles are of composite section with reinforced concrete within the upper 17m of the steel tube. Three trial piles were installed in the dock to investigate the driveability and performance of the driven steel tubular piles. The piles were subjected to dynamic and static load testing. Loads were applied in both vertical and horizontal directions. Vibrating wire strain gauges were installed on the inside of the steel piles, on the reinforcement and in the concrete to determine the relative proportions of the applied load carried by the steel tube and concrete infill and to establish how these proportions varied along the length of the piles. Inclinometers were also installed to monitor the lateral deflection of the piles. This paper describes the driving, construction and testing of the three trial piles. The results of the vertical and horizontal loading tests are discussed and comparisons are made between dynamic and static tests carried out on the piles.

Jan 1, 1989

By P. van Meurs, C. van der Poel

From observations of the linear displacement of oil by water from a porous medium as visualized in transparent models, new insight into the mechanism of vircous fingering, as occurring in the case of unfavorable oil-water viscosity ratios, has been obtained. A mathematical description of the observed phenomena leads to formulas. expressing both oil production and pressure drop across the formation as a func-tion of cumulative water injection with the oil-water viscosity ratio as a parameter. Theoretical results are compared with those obtained from scaled laboratory experiments in sand-filled rubes in which water was injected at the one end and production was obtained from the other end. In the second part of the paper the same principles are used to calculate a more realistic production scheme in which production of oil and water is obtained from wells regularly distributed over the field. Results show satisfactory agreement with production data of an actual oil field. Application of the theory is extremely simple as only a limited number of readily available parameters have to be known and results are presented in an analytical form. INTRODUCTION When oil is displaced from a porous medium by water having a viscosity lower than the oil. the oil-water interface is essentially unstable and has the tendency to break up into what are called "fingers" or "streamers". This Viscous fingering has been noted before by Engelberts and Klinkenberg' and has recently been demonstrated in transparent models by van Meurs-. It is highly questionable whether it is at all possible to perform relative permeability measurements In the laboratory reproducing the same distribution of water and oil in the cores as Present in practice. Therefore, we based our descriptive theory on an idealized model which was "tailored" to the fingering mechanism as observed in transparent models under scaled conditions. This approach was the more attractive, as a highly simplified model had already yielded an adequate description of the process. Though we are aware our theoretical approach can be extended in several ways, it is given here in its simplest form to explain the fundamental principles and to avoid complicated formulas. SIMPLEST CASE OF A LINEAR DRIVE Observations and Theoretical Model In Fig. 1 a series of photographs shows how water penetrates into a formation saturated with an oil which is considerably more viscous than the water. The technique for obtaining these photographs, using transparent models, has already been described?. The fingers can be clearly observed and are seen to be mainly parallel to the flow direction. Note that the contours of these fingers are not smooth but show protrusions of water enclosing oil pockets.

By Viviam Serra Marques Pereira

Aços ARBL são utilizados na fabricação de tubos para transporte de gás natural e petróleo e, devido ao ambiente agressivo, rico em H2S, em que são aplicados, devem resistir à fragilização por hidrogênio. No presente trabalho, verificou-se qual a influência do alongamento longitudinal dos grãos de um aço API X65, com baixo Mn, sobre a permeabilidade de hidrogênio. O material foi caracterizado com a utilização dos microscópios óptico e eletrônico de varredura e os ensaios de permeabilidade foram conduzidos com base na norma ASTM G 148-97. A microestrutura do aço era composta por ferrita e perlita, com baixo teor de inclusões arredondadas de Al e Ca e sem bandeamento. Com os resultados obtidos a partir dos ensaios de permeabilidade, calcularam-se os coeficientes de difusão efetiva do hidrogênio nas seções longitudinal e transversal do aço, e o valor do primeiro se mostrou levemente superior ao do segundo. Isto indica que pode haver influência do alongamento longitudinal dos grãos sobre a permeabilidade de hidrogênio.

Aug 16, 2017

By W G. Szymczak, Leslie C. Taylor

The University of Maryland (UMD) has conducted a series of small-scale tests using explosive charges buried in saturated sand. Twelve different combinations of depth of burial of the charge and height of the target plate above the soil were tested. The target plates did not deform plastically. High-speed video was used to track the motion of the plate. The video data are analyzed to determine the position and velocity of the plate as a function of time. The results of this analysis are compared with computations performed at NRL using the BUB2D computer code. This code treats the saturated sand as an incompressible visco-plastic fluid which yields according to a Drucker-Prager (frictional-cohesive) yield surface. Comparisons of simulations with experiments are presented. In the cases examined so far, the velocity grows very quickly to a peak and then slows, first with a deceleration greater than one “g,” which then transitions to an approximately one “g” deceleration. An analysis of air drag on the plates has shown that its effect is negligible in the time span of interest. In all cases in which the BUB2D code can be applied, the computations compare favorably with the results of the data analysis. This suggests that the code and model used in the computation are properly capturing the physics of the interaction between the soil and a non-deforming plate.

Jan 1, 2007

By G. L. Oldright

The data presented in this paper were collected at the smelter of the Consolidated Mining & Smelting Co. of Canada, Ltd., Trail (Tadanac), British Columbia. Many thanks are due to S. G. Blaylock, vice president and general manager, James Buchanan, smelter superintendent, and George Murray, assistant smelter superintendent, for their broad general policy in permitting these data to be taken and published. life are also grateful for the help given by the staff members stated in Paper XI, Report of Investigations Acknowledgment is given several excerpts from experiments by F. E. Lee, head of the research staff. INTRODUCTION The past reputation of zinc as an ingredient in lead blast furnace slags has been bad. Zinc is thought of as a cause of accretions in the shaft of the blast furnace, of hot tops, of the formation of "zinc mush" in the crucible and forehearth, of lead-rich slags, of viscous slags, and. of low capacity in smelting.

Jan 1, 1934

Site specific geotechnical data, deposit characteristics and method of mining are key factors when assessing an appropriate slope design philosophy. Mining geotechnics should be viewed as an iterative design process linked closely with mine planning, development and operational safety constraints. This case study presents geotechnical investigations for slope design at Macraes Flat Gold Mine using kinematic, probabilistic and economic analyses tempered with knowledge of site specific conditions. The recommended designs not only reduce early waste stripping tonnages but also provide data to optimise final walls.

Jan 1, 1992

By P. J. Baguley

The model has been developed on the basis of the observation that the partitioning behaviour of a particle is related to its calculated terminal velocity. It utilises a theoretical calculation of the terminal velocity of each particle class. This is then correlated with the observed partition data for a plant separator using empirically-derived functions of operating conditions which take into account effects such as bath turbulence, holes in drum lifters and feed arrangements. The model successfully decouples the effects of medium density and viscosity and is appropriate for any bath-type separator. The correlation between calculated terminal velocity and actual partitioning behaviour was established and modelled using data obtained from two Wemco drums treating Fe and Mn ores. The model can be used to predict the prevailing size-by-size partition curves and the separation (product grades/recoveries) given the washability of the feed and operating conditions. Simulations are used to show that, for the treatment of Fe ore, there is a maximum medium density beyond which product grades fall and that this maximum decreases as the proportion of magnetite in the medium increases. This is attributed to the dominant effect of viscosity at higher medium solids concentrations

Jun 18, 1905

By J. X. Wu

An investigation on the seismic damage to buildings with pile foundations in Tianjin region, was conducted after the earthquake which hit Tangshan in 1976. It showed that most pile-founded buildings have an excellent aseismic capacity. In this paper, several pile-founded projects suffering the seismic damage are introduced as examples, simplified calculations are made of the vertical bearing capacity of pile foundations and of the horizontal seismic force, and suggestions are presented in conection with the design of pile foundations in the liquified ground soil. The paper shows a frame structure which has a plie foundation with a box-shaped base. Analyses if its response to the earthquake has been carried out in accordance with the F.E.M. and results have been obtained.

Jan 1, 2010

By Philip J. H. Ball

The new application and development of grout jacking processes has combined, over the last decade in particular, to provide a method by which the effects of new underground construction on superficial structures can be controlled to acceptable levels. This paper sets out the basic principles, processes and limitations of compensation grouting. It describes key elements of the philosophy and design and details the control systems required to perform satisfactorily. To illustrate the application, a case history is described for the construction of a shaft and tunnel within and beneath the prestigious structure of Harrods in London.

Jan 1, 2000

By Michael Alber

Resin grouted rock bolts are the major support measure in coal mining. They are rather easy and foolproof to install, take immediately load and are the least time consuming support measure for controlling gateroad deformation. The use of only resin grouted bolts allows fast gateroad development which is essential for economical resource exploitation. The design of reinforcement / support systems for coal mining typically bases on empirical methods, which work fine when encountering known or usual ground conditions. However, coal mining approaches depths where little experience exists and numerical modeling is often the only method to estimate ground behavior. This paper discusses the geotechnical properties relevant to numerical model and focuses particularly on input values for modeling resin grouted rock bolts for safe gate design.

Jan 1, 2006

By R. A. Wood, R. I. Jaffee, H. R. Ogden, D. N. Williams

Strain-induced porosity has been found to occur in titanium and other materials at tensile strains greater than the uniform elongation of the material. Porosity in titanium increases with increasing strain and temperature, being most severe at 300° to 800°F. Strain-induced porosity is believed to be a normal part of the mechanism of deformation in ductile materials. DURING the past few years there have been numerous references to the occurrence of voids in laboratory test specimens of metals subjected to strain.l-7 These voids have been referred to as intercrystalline cracking, strain-induced porosity, intergranular cav-itation, voids, and porosity. They appear to occur at grain boundaries or interfaces, and are generally associated with large amounts of strain and have been found mostly in creep specimens and to a lesser extent in tensile specimens. Because the phenomenon does not occur unless the material has been strained,

Jan 1, 1960

By Jeffiey B. Austin, Maurice Tagami

"The ores of the Iberian Pynte Belt are typically massive sulphide ores with very fine grained mineral textures. EuroZinc Mining Corporation is currently evaluating one of the massive sulphide deposits located near the town of Aljustrel, in South Central Portugal. The deposit contains significant grades of lead, zinc and silver. The ores are comprised solely of sulphide mineralization consisting of pyrite, sphalerite, galena and some secondary copper minerals. Liberation requirements for these ores are typically 22 to 25 microns. A selective flotation process has been utilized to produce separate lead and zinc concentrates for sale to off-site contract smelters.This paper outlines the process test results and describes the process parameters required to optimize the process parameters. Ths test program has been conducted in support of the re-opening of the facilities in Aljustrel. The 3500 tpd mining and milling facility was commissioned in 1990 and operated for 18 months before closing. The previous facility was designed to produce three products using a selective copper-lead-zinc flotation process. EuroZinc Mining Corporation is proposing to re-open the operation, selectively mining from a lead-zinc phase of the massive sulphide deposit and produce only lead and zinc concentrates.Results are presented and discussed.PROJECT HISTORY AND CURRENT PROJECT OBJECTIVESThe EuroZinc Aljustrel Project is a potential major producer of lead, zinc and silver located in the Iberian Pyrite belt of south-central Portugal. The town of Aljustrel is historically associated with mining dating to the time of the Romans. The area is rich in pyrite deposits, and sections of the pyrite deposits contain significant zones of copper, lead, zinc and silver. Mining in Aljustrel during the last century (1900’s) included a major pyrite mining operation, which produced feed for sulphuric acid production. Pynte mining operated from the 1930’s to the early 1970’s and a short-lived base metal operation from 1989 to 199 1."

Jan 1, 2000

By S. K. Gilman

Zircon (ZrSiO4) sand production of about 1.1 Mt/a(1.2 million stpy) predominates the global supply of zirconium minerals. Baddeleyite (ZrO2) contributes less than 1 percent of supply. Zircon is almost exclusively produced as a co-product from the mining of titanium minerals, mainly from mineralized beach sands. In 2004, there were a number of new projects under consideration that were more dependent on zircon revenue than for titanium minerals. This reflected sustained higher zircon prices and forecast ongoing supply shortages in the absence of major new discoveries.

Jan 1, 2005

Your thoughts on the current status of the global minerals industries? The global economic, technological, social and political changes of the last two decades of the 20th century resulted in the emergence of a restructured minerals industry. This industry is now based on a new cost-cutting philosophy; utilization of modern technology; productivity gains rather than production tonnages; diversification of mineral markets; and globalization of exploration, mining and processing. Quantity and tons used to be the focus. The emphasis today is on remaining competitive in the marketplace by lowering per-unit production costs as much as possible. What factors and trends will impact the minerals industries in this, the 21st century? A number of parameters will impact minerals operations and shape the future sustainability and growth of the minerals industries. Increased demand for minerals will be accompanied by the demand for technical advancements. We will also see a continued emphasis on health and safety, environmental stewardship, and education and training. Let me elaborate.

Jan 1, 2002

By K. Hanna

This U.S. Bureau of Mines report describes a rock mechanics instrumentation program conducted in a shallow underground coal mine in central Illinois. This research program was designed to provide a basic understanding of the structural behavior of entry intersections. A wide variety of instruments and measurement techniques including hydraulic borehole pressure cells, multiple-point borehole extensometers, roof bolt compression pads, and overcoring were employed to monitor roof stresses, pillar loading, strata movement, floor heave, and bolt loading before, during, and after intersection development. A summary of intersection design theories, failure modes, and support techniques is included and instrumentation installation procedures and analysis methods are presented. The study identified two critical parameters that affect intersection stability: in situ horizontal stresses and geological discontinuities. Important design parameters for improving intersection stability are roof span and intersection geometry.

Jan 1, 1991

By F. D. Richardson

STAFF: Editor, Gerhard Derge Carnegie lnstitute of Technology Schenley Park Pittsburgh, Pa. 15213 Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: Jack H. Scoff, President; Richard C. Cole, Past-President; Harold 0. Emerick, President-Elect; Ralph L. Hennebach, Treasurer; Robert W. Shearman, Secretary; Donald A. Parks, Assistant Secretary; Leslie S. Wilcoxson, Assistant Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. E. Lund, Chairman; T. E. Dancy, H. O. Emerick, P. R. Gouwens, R. E. Grace, J. H. Jackson, H. H. Johnson, A. E. Lee, Jr., R. R. Nosh, R. D. Pehlke, and Paul Queneau. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extroctive Metallurgy Division: R. E. Grace, Choirmon; G. M. Bell, D. W. Bridges, J. M. Cigon, G. W. Heoly, T. A. Henrie, R. D. (Holli-doy, C. E. O'Neill, C. S. Somis, A. W. Schlech-ten, and Charles Shull. Iron and Steel Division: R. D. Pehlke, Choirmon; T. P. Floridis, Arnulf Muon, G. R. St. Pierre, E. T. Turkdogan, L. H.Von Vlock, and J. M. Uys. lnstitute of Metals Division: H. H. Johnson, Jr., Chairman; J. B. Clark, Vice Choirmon; M. R. Achter, G. F. Bolling. J. O. Brittoin, G. P. Conard, II, R. S. Davis, L. A. Girifolco, G. T. Hohn, J. P. Hirth, L. Himmel, G.T.horn, George Krauss, J. D. Livingston, R. D. Manning, H. M. Otte, S. V. Rodcliffe, R. E. Reed-Hill, H. C. Rogers, E. ScaIa, O. Sherby, M. T. Simnad, G. R. Speich, E. A. Steigerwald, R. A. Swolin, W. A. Tiller, W. R. Upthegrove, J. B. Wagner, Jr., Derek Wolton, H. W. Weart, W. W. Webb, and D. Published seven times yearly in February, March, April, June, August, October, and December by the American lnstitute of Mining, Metallurgical, and Petroleum Engineers, Inc., 345 East 47th Street New York, N. Y. 10017. Telephone PLAZA 2 -6800. Subscription $30 per year for non-AtME members m United States and North, South, and Central America; $32, foreign; $7.50 for AlME members Single copies, $6.00, single copier foreign, $6.50. The AiME is not responsible for any statement made or opinion expressed in its publications . . . Copyright 1964 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AiME New York Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts. Second dost postaas poid ot New York, N. Y.,ond Ann Arbor, Mich. Volume 230, Number 6.

Jan 1, 1964

By R. Blickensderfer

The sparking and gas-igniting tendency of steels and alloys were evaluated my measuring the radiance of spark showers produced by grinding a sample on an abrasive wheel in air, the time required for a spark shower generated on an abrasive wheel to produce an ignition in an explosive gas mixture, and the energy and speed required for impacts between various materials to ignite an explosive gas mixture. Mixtures of air-methane were found quite resistant to ignition by showers of sparks. A mixture of air-9.S pct hydrogen was used to increase the sensitivity of the tests and to thereby extend the range of materials that could be evaluated. The results of the spark-shower tests indicate that carbon steels and the alloy steels found in coal-cutter tools are among the most sparking and most incendive of any materials tested. Stainless steels, nickel alloys, and tungsten carbide are among the least sparking and least incendive. The brightness of the spark showers depended upon the degree of oxidation of the abraded particles. Impact tests against hard rocks such as solid quartz and sandstone, showed that high-carbon steel was more inc endive in the hydrogen mixture than were the softer steels or the alloy steels found in coal cutters. Ignitions were found much less likely to occur at speeds somewhat lower than the speeds currently in use in continuous mining machines.

Jan 1, 1972