Search Documents

By Helen D. Robinson

Traditional practice to resist large lateral loads on foundations is the use of large diameter caissons, battered driven piles, or battered micropiles. Dense urban construction environments, however, limit the usefulness of these systems due to the close proximity of below- and above-grade obstructions. This paper presents two micropile construction projects in the United States where a complex scheme of battered micropiles and grade beams was developed to counteract large lateral loads at the foundation level. The paper also presents a procedure used to design vertical micropiles for large lateral loads, which can greatly simplify the design of foundations subject to significant lateral loads in urban environments. A design example shows a case where vertical micropiles were used to support allowable design lateral loads greater than 80 kip per micropile.

Jan 1, 2010

[ENGLISH active earth pressure adapter additive adhesion admixture, addition adsorbed water aggregate air air entrainment air hose allowable bearing value allowable pile bearing load]

Jan 1, 1994

By Rita D. Sylvester

"This compilation lists and summarizes publications by Bureau authors published in the regular Bureau of Mines series, in scientific, technical, or trade journals, or in other media; those available from the Bureau of Mines are indicated. Patents issued to Bureau personnel are also listed, and instructions are given on how to apply for permission to use them. One of the outstanding features of this Special Publication is an exhausive subject and author index. IntroductionThe Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and present their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries, The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminar's; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1970, to December 31, 1974. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;2 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;3 and the 5-year lists of Bureau publications and articles from January I, 1960, to December 31, 1964,4 and from January I, 1965, to December 31, 1969.5 It includes all the material in the four annual lists of Bureau publications and articles from January 1, 1970, to December 31, 1973."

Jan 1, 1975

By Philippe Poirier

Les parcs à résidus miniers représentent un risque environnemental qui nécessite une gestion adéquate. Suite à la publication du « Guide sur la gestion des parcs à résidus miniers » en septembre 1998, les membres de l?industrie minière ont appliqué les éléments de gestion du Guide, permettant ainsi une amélioration continue des opérations. En février 2000, l?industrie minière a indiqué le besoin d?établir des lignes directives plus spécifiques pour l?opération sécuritaire des parcs à résidus. Dans cette optique, l?Association Minière Canadienne a publié, en septembre 2002, un Guide pour l?exploitation, l?entretien et la surveillance (EES) des parcs à résidus miniers. Suite au développement du Guide et à son application sur plusieurs sites miniers, il apparaît que la mise en oeuvre d?un Manuel ESS des parcs à résidus miniers permet : ? d?établir les responsabilités des intervenants; ? de s?assurer que les critères d?opération sont appliqués; ? de mettre en oeuvre le plan de déposition des résidus et de gestion de l?eau; ? de rencontrer les normes et exigences environnementales; ? de définir un programme d?entretien et de surveillance des ouvrages; ? d?identifier les risques et de mettre en oeuvre un plan d?intervention d?urgence; de démontrer une opération diligente.

Nov 1, 2002

By Nuno Cruz

"The concrete overbreak estimation for bored piles provides the quantification of the shaft’s expansion beyond its theoretical volume. There are stability analysis methods that can be employed before and after concrete pour but as for the moment of decision, during pile cast, the most common method still consists in measuring the rising of the concrete level in order to compare its poured volume with the theoretical pile section volume. This is a determinant parameter to monitor, not only because it assesses the bored shaft stability but also because it represents a direct cost. When analyzing the estimation methods commonly applied on-site it becomes evident that these are often affected by human errors that lead to misleading results. The objective of this paper is to identify those errors and discuss a subject which is usually overlooked. As a general conclusion, it was ascertained that most errors derive from inaccurate volumetric data, working procedures and gauging equipment. By acknowledging these widespread practices deep foundations contractors will be in a better position to make informed decisions on how to correct and improve bored pile stability.GENERALBackgroundWhen executing bored piles, the estimation of its concrete overbreak allows a swift appraisal of the excavation stability during the drilling process. This is simply obtained from the proportion of the poured volume of concrete over the drilled shaft theoretical volume, as shown in equation [1].Where CO = concrete overbreak percentage, Vc = volume of poured concrete, Vr = pile’s theoretical volume. This calculation not only provides a general idea of the shaft’s expansion from its theoretical volume, but also the outline of the excavated column’s geometry. For the latter, the outline will be as accurate as the number of measurements taken for each partial known volume of poured concrete. This means that for each load placed inside the excavation there is a corresponding rising of the concrete level. The profile of the definite pile is then plotted (see Fig. 1) and allows inferring about how stable remained the shaft walls up to the moment of casting.The technological developments in this area have provided other methods for determining pile stability before and after pile cast, such as ultrasonic echo sensing, cross-hole sonic logging or thermal integrity profiling systems. Notwithstanding, concrete overbreak assessment remains as common practice and confers the advantage of providing stability information during the process of pile casting."

Jan 1, 2017

By D. J. Dollhopf

A week-long selective overburden handling dragline op ration was conducted at a strip mine near Colstrip, Montana. The objective of the demonstration was to hvdrologically isolate a saline overburden zone during placement in the spoil piles. The saline zone had concentrations considered inimical to successful reclamation and was potentially dangerous to future water quality in the spoils aquifer. The zone was identified after review of chemical data for overburden samples collected from the intense 60 m grid drilling pattern. The saline zone in the overburden was: 1) handled in a normal manner; 2) segregated and buried; and 3) segregated, buried, and covered with a relatively impermeable 1.0 m thick clay cap. The method used to formulate this demonstration, the demonstration itself, and the monitoring and evaluation techniques are described in this report. Observation wells were installed to monitor ground water in the overburden, Rosebud coal, and McKay coal. Data from these wells were, used to estimate post reclamation water levels and to evaluate recharge and water movement characteristics in the vicinity of the demonstrations. The inimical zone was successfully handled in a selective manner with a minimum of delays. Economic analysis indicated cost of these selective burial operations to be about 1.1 to 1.5 times the cost of the normal operation at this particular mine site. Long term monitoring will be required to evaluate the effectiveness of these handling techniques in hydrologically isolating undesirable overburden materials.

Jan 1, 1977

By A. Bouvard, N. Hoteit, E. Boidy, F. Pellet

In the context of the construction of an Underground Research Laboratory devoted to the feasibility studies of radioactive waste deposits, it appears of the utmost importance to study the long-term behaviour of rock, over a long time period. In this paper, some results of tests performed on the argillite from the Meuse-Haute-Marne site test in Eastern France are presented. Then a numerical simulation of one of this test using the viscoplastic damaging constitutive law proposed by Lemaitre is presented. Finally, this law is used to simulate numerically the behaviour of the rock at the wall of a circular tunnel in order to determine the extension and the change along the time of the Excavated Damaged Zone (EDZ). Advantages and limitations of the model are discussed. Dans le cadre de la réalisation d’un laboratoire de recherche souterrain conçu pour étudier la faisabilité d’installations de stockage de déchets radioactifs, il apparaît fondamental de caractériser non seulement le comportement viscoplastique à très long terme des matériaux mais aussi les phénomènes d’endommagement consécutif à la redistribution de contraintes provoquées par l’excavation des cavités. On présente ici les résultats d’essais réalisés sur les argilites du site de Meuse/Haute-Marne et destinés à caractériser leur comportement visco-endommageable. Il est ensuite procédé à une application de la loi viscoplastique endommageable de Lemaitre pour simuler l'un de ces tests. Les apports et les limites d'un tel modèle sont mis en évidence par des simulations numériques du comportement de la roche au pourtour d'une galerie circulaire permettant de suivre l’évolution au cours du temps de la zone endommagée (EDZ) à la paroi . Im Rahmen des Baus eines unterirdischen Forschungslabors für die Untersuchung der Machbarkeit von Deponien für radioaktive Abfälle erweist es sich als äußerst wichtig, das langfristige Verhalten von Gestein über einen langen Zeitraum zu untersuchen. Im vorliegenden Artikel werden einige Ergebnisse von Untersuchungen vorgestellt, die mit Tonschiefer aus der Meuse-Haute-Marne in Frankreich durchgeführt wurden. Anschließend wird eine numerische Simulation der Untersuchungen unter Verwendung des von Lemaitre vorgeschlagenen viskoplastischen Verformungsgesetzes vorgestellt. Schließlich wird dieses Gesetz auf die numerische Simulation eines Kreistunnels angewandt, um die Ausdehnung und die zeitliche Entwicklung der Auflockerungszone (EDZ) zu bestimmen. Es werden die Vorteile und Grenzen des Modells diskutiert.

Jan 1, 2003

By C. W. Handy

ONE LAW cannot he evaded, the economic law of supply and demand. Silver, like any other commodity, is subject to this law; and its price in the long run is determined by existing conditions. I say "in the lone run because at times silver has appeared to mope contra to basic coalitions. Such movements, however, are, occasioned by the market's attempt to anticipate changes in these governing conditions. If the expected changes materialize then the new market level is justified, but if they do not then the market will revert to its previous status, A striking example of such a move occurred in November when the price advanced over 70, in ten days and then in the next two weeks lost more than it had gained. The reasons for this advance were that the speculative element interpreted certain events as favorable to silver namely, England suspension of the gold standard, higher shat prices, and the Chinese-Japanese crisis. When these expectations proved unjustified the inevitably, elapse followed became the governing conditions had not channel.

Jan 1, 1932

By Han Jie

The results of full scale plate load tests on stone columns on soft clay in coastal areas are presented in this paper. Four load tests were made, two of which were performed on the ground treated with stone columns, one on an isolated stone column and the last one on the untreated ground. For a given stress range, the settlement of the rigid plate, the stress concentration factor, and the excess pore water pressure were measured. It is found that the distribution of vertical stress beneath the rigid plate supported by the composite ground of stone columns is very different in shape from the one by the untreated ground, that the stress concentration factor has a relation with the stress level and time, that the stone columns increase the bearing capacity up to by 2 times, and that the ground stabilized by stone columns is of great advantage to keep the foundation stable.

Jan 1, 1991

By Michel Aubertin

Les rejets miniers sont communément utilisés, depuis plus de 60 ans, comme matériau de remblayage des chantiers souterrains. Les roches stériles et les rejets de concentrateur sont employés comme remblais car ils sont disponibles sur les sites miniers à un coût réduit pour aider au support de terrain. Le remblayage des ouvertures est également avantageux car il permet de réduire la quantité de rejets entreposée en surface. Dans les mines souterraines, le remblai des chantiers doit aider à maintenir un espace de travail sécuritaire, tout en favorisant la récupération du minerai et le contrôle de la dilution. Il est alors essentiel d'évaluer précisément les pressions exercées par le remblai sur les murs et sur les barricades installées près de la base des chantiers. Dans cette présentation, des solutions existantes pour évaluer les pressions dans les chantiers sont brièvement revues. Les auteurs présentent ensuite des solutions analytiques récemment développées à cette fin, qui permettent de tenir compte du transfert des contraintes du remblai aux parois des chantiers et des galeries. Les solutions proposées, qui sont basées sur la théorie de l?effet d?arche, prennent en compte l'influence de la géométrie des ouvertures et de la position des barricades. La méthode de calcul permet aussi de calculer l?effet des pressions d?eau pour un remblai partiellement ou totalement submergé. Les solutions s'appliquent au cas d?un remblai récemment mis en place, alors que l?effet de la pression interstitielle ne peut pas être négligé, et aussi à plus long terme sous une condition drainée. Des résultats expérimentaux et des simulations numériques sont utilisés pour valider les équations proposées. Les résultats analytiques et numériques montrent notamment que la pression totale sur une barricade peut être grandement augmentée par la pression d?eau, tandis que la contrainte effective peut être réduite par les pressions interstielles (par rapport à la condition drainée ou sèche). On discutera aussi des implications pratiques de ces résultats pour l?application des remblais souterrains.

Nov 1, 2008

By Richard E. Thill

Engineering properties of rock are essential in most phases of mining from site reconnaissance through mineral processing. Review of the literature indicates, however, that property data is scarce for most coal measure rocks in the United States. The Bureau of Mines, U.S. Department of the Interior, has undertaken a wide-ranging testing program to provide more complete property data for coal strata in the U.S. coal basins. The property data are expected to have application in geophysical exploration, the development of pre- mining and hazard detection probes and instrumentation, mine design, engineering and rock mass classification, subsidence engineering, and ground control. This paper describes the comprehensive program encompassing in situ geological, geophysical, and geotechnical properties and laboratory determinations of acoustic, electromagnetic, physical, mechanical, and index properties and discusses results for 500 ft of coal measures at a minesite in the Northern Appalachian, Eastern Coal Province.

Jan 1, 1982

By L Edwards, M Haest, D Mittrup

The focus in the iron ore industry has shifted from increasing production volumes with less regard for cost, to efficient production of quality tonnes. BHP Billiton iron ore geoscience and exploration has embedded infrared spectroscopic sensing of drill hole samples to help meet this challenge.Infrared spectroscopy is delivering mineral predictions that are used for (automated) geology logging and modelling. The spectra are processed together with other available data sets to predict geometallurgical and geotechnical variables that include lump per cent and uniaxial compressive strength.Trials are ongoing to test the benefit of infrared spectroscopy during mining, including the analysis of grade control samples and remote sensing of mine faces. Results show great benefits in the fields of short-term geology modelling, better understanding of material (handling) properties, identification of geotechnical risk areas and high resolution ore-waste delineation.These trials are bringing BHP Billiton iron ore closer to its ultimate goal of having infrared spectroscopic data collected across the mining value chain. Once such data are available everywhere, regression models can be trained at one point (eg iron grade model trained on exploration samples) and be applied elsewhere (eg iron grade predicted on mine faces). Such predictive analytics will enable not only high precision mining, but also provide maximum time to tailor plant design to the ore in the ground, based on learnings from ores processed in other plants. This will improve planning outputs that will eventually increase mining efficiency, processing capability and product quality.CITATION:Haest, M, Mittrup, D and Edwards, L, 2017. Infrared spectroscopy in BHP Billiton iron ore with a focus on in-mine infrared sensing, in Proceedings Iron Ore 2017, pp 549–556 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By C. H. Larsen

A 9-month study of the uses of wire rope associated with U. S. underground coal mining is reported. Rope applications are broken down into hoisting and nonhoisting applications where "hoisting" refers to transport in vertical and inclined shafts. The former receives the greatest emphasis since it represents the most critical rope application from the stand-point of production and safety. The discussion of hoisting practice includes aspects related to the mine operators as well as those related to the equipment builders and wire rope manufacturers. U. S. state and Federal laws regulating hoisting and wire rope use are also presented and discussed. Canadian and other foreign hoisting practice and laws are included. The state of the art in electromagnetic nondestructive inspection of hoist ropes is presented. Capabilities and use of one Canadian electromagnetic device are discussed in great detail. Conclusions are drawn regarding the present state of wire rope and hoisting technology in U. S. coal mines. Recommendations are made for improving rope practice, in general, and hoisting, in particular, consistent with greater safety.

Jan 1, 1971

By W. Banda

"Trial application of air decks on a production shot improved fragmentation (32% reduction in x50). Empirical fragmentation models and digital image processing software were used to estimate fragment size distribution of the blasted muck pile. The x20, x50, and x80 passing fractions, and top size were 42, 265, 683, and 1,455 mm, respectively. Air-deck application reduced explosives load in blastholes, lowering total charging cost by US$20/hole (15% decrease) and the powder factor to an average of 0.86 kg/m3 (12% decrease). Blast results were 443,624 t of blasted material from the block (90% of total muck pile) was smaller than 900 mm.RÉSUMÉ L’application pilote de trous d’air dans le cadre du coup de mine effectué pour commencer la production a amélioré la fragmentation (une réduction de 32 % des x50). Des modèles empiriques de fragmentation et un logiciel de traitement numérique des images ont permis d’estimer la composition granulométrique des fragments du tas de déblais abattus. Les fractions de passé de crible de x20, x50, x80 et la dimension supérieure étaient représentées par des dimensions respectives de 42, 265, 683 et 1 455 mm. L’application de trous d’air a permis de diminuer la charge d’explosifs nécessaires dans les trous de mine, réduisant ainsi les coûts totaux de chargement de 20 $ US/trou (soit une réduction de 15 %) ainsi que le facteur de chargement (facteur poudre) à une moyenne de 0,86 kg/m3 (soit une réduction de 12 %). Les coups de mine ont résulté en 443 624 tonnes de matériaux abattus du bloc (soit 90 % du tas de remblais total) mesurant moins de 900 mm. INTRODUCTIONThe main objectives of production blasting are to achieve optimum rock fragmentation and to minimize overall production costs. Because blast fragmentation significantly affects the profitability of a mine, blasting is the first step of the size reduction in mining: An optimum size distribution is required to maximize the performance of mining and subsequent milling processes. If the fragmentation size distribution can be modelled and controlled, operations performance will improve. Blast fragmentation modelling is important in mineto- mill optimization: It allows the estimation of blast fragmentation distributions that can be modelled in downstream mining processes to determine the optimum blast design."

Jan 1, 2018

By Dave Kay, Young-Suk Song

To meet the needs of South Korea's rapidly expanding economy, a large number of infrastructure projects are under way to improve transportation efficiency within the nation. These projects include high-speed rail links between major population centres and improvements to the road network. Being densely populated and geographically mountainous, infrastructure development in Korea requires a significant amount of tunnelling. Owing to the predominantly hard granitic nature of rock, drill and blast is the preferred method of tunnel advance. The Korean tunneller, however, faces the same pressures as those of his international counterpart in that both cost and production targets need to be achieved while meeting expectations of both community and regulator.

Jan 1, 2005

By R. T. C. Rasmussen

"INTRODUCTION The primary purpose of the Bureau of Mines electrolytic manganese pilot plant at Boulder City, Nev., is to improve the Bureau-invented electrowinning process and to determine the applicability of the process to the extensive domestic low-grade manganese ores with a view to making the United States dependent upon foreign sources of manganese. 3/4/ Incidental to accomplishing this purpose, the pilot plant has produced a substantive quantity of electrorytic manganese since the start of operations late in 1941; present cabacity about 1 ton a day of manganese metal. A second important purpose of the pilot plant is the supplying of electrolytic manganese for full-scale tests in cooperation with industrial users of manganese.The Rustless Iron& Steel Corp., Baltimore, Md., was the first steel company to cooperate with the Bureau of Mines in large-scale testing of electrolytic manganese. Arrangements were made with C. E. Tuttle, then president of the corporation, whereby the Bureau would supply electrolytic manganese to make a sufficient number of full-scale stainless-steel heats to demonstrate thoroughly its merits as a replacement for low-carbon ferro-manganese in the corporation's stainless-steel practice. The corporation's purpose in the investigation was to determine the possible advantages of electrolytic manganese resulting from its almost complete lack of phosphorus and caroon that might offset its then considerably higher cost per unit of manganese than low-carbon ferromanganese. The data presented herein are based upon reports of A. L. Field, technical director, and L. Weitzenkern, research engineer of Rustless Iron & Steel Corp.; they are supplemented by observation of the author who visited the plant during the tests."

Oct 1, 1945

Organization Place Date 1917 American Electro-Chemical Society Detroit; Mich. May 2-5 American Waterworks Association Richmond, Va. May 7-11 American Institute of Electrical Engineers New York City May 18 America' Society of, Mechanical Engineers Cincinnati, Ohio May 22-25 American Iron and Steel Institute New York City May 25-26 ' Interstate Oil Mill Superintendents Association. Augusta, Ga. May (last wk.) Electric Power Club Hot Springs, Va. June 11-14 Society for the Promotion of Engineering Education .... Evansville, Ind. June 19-22. American Institute of Electrical Engineers Hot Springs, Va. June 25 American Society for Testing Materials Atlantic City, N. J. June 26-30

Jan 5, 1917

By Leroy E. Schulze

A review of development and a reevaluation of uses of the hydraulic air compressor are suggested by the constant changes in technology, which frequently make an old art valuable in solving current problems. Contacts with research workers in various branches of engineering indicate that this older method of producing compressed air may not be familiar to some or that its salient features might be useful in solving problems involving uses of compressed air. Briefly, a hydraulic air compressor may be described as an inverted siphon, consisting of an intake head where water and air are mingled, followed by a gravity-fall tube in which air is intimately mixed with the water and is compressed as the water pressure increases during the fall down the tube, then a separating, or stilling, chamber in which air bubbles rise to the surface of the water and collect in the upper portion of the chamber at a pressure equal to the weterhead maintained by the height of water in the discharge leg of the circuit. The water, which now contains only the fraction of air that has gone into solution, passes out of the separating chamber and rises up the discharge leg to the surface, which is, of course, at some suitable distance below the level of the intake. Present-day applications include (1) utilizing low hydraulic heads, which otherwise have little commercial values; (2) utilizing low hydraulic heads in reclamation work to supply compressed air, or in some instances to produce a small suction, for air-lift pumping (or for operation of air motors), with minimum attendance and without need for electric power; (3) utilizing medium heads, as at dam and lock installations, to produce compressed air for pneumatic operation of airlifts, gates, valves, and rubber gate seals; (4) utilizing underground waters, as in mines, to produce compressed air for general mine use; (5) using this method of isothermal compression of air in combination with standard compressors wherever hydraulic head is available, thereby securing the advantages of low-temperature intake to the mechanical compressors and reduction of moisture content below that of atmospheric air; (6) development of large air supply at pressures up to 150 p.s.i.g., which, after performing work in reciprocating or centrifugal expansion cylinders, is available at temperatures approximating -50° F. Possibilities in freezing and reheating should be mentioned which may prove economical for obtaining uniformly dry air for process work, wind-tunnel tests, or large air-conditioning installations, such as ventilation of underwater traffic tunnels, and may be economic for supply of supercharged air to gas-turbine plants.

Jan 1, 1954

By Robert J. Shanley

The computer program, HYBMODE, has been developed to meet the need for a fast and economical method for clustering data points on the sphere. The algorithm used in this development is an extension of D. Wishart's one-level mode analysis. The program can be used to cluster either vectorial or axial data; it is currently being used by the Bureau of Mines to cluster fracture orientations.

Jan 1, 1974

By Charles D. Walcott

Jan 1, 1901