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By Murad Y. Abu-Farsakh

This paper presents the analyses of load-transfer (t-z) behavior of twelve prestressed concrete (PSC) instrumented test piles that were driven in different locations of Louisiana. The load transfer method is an efficient and practical tool for the analysis of single driven pile to predict the ultimate load. The test piles were instrumented with vibrating wire strain gauges in order to calculate the shear transfer for different soil layers during the static load test. The static load test was performed on all the test piles after 10 to 14 days of end of driving. Empirical load-transfer models were proposed previously by different researchers (Fleming 1992, Hirayama 1990, Krasinski 2012, Bohn et al. 2017) after analyzing the instrumented test pile results. For this study, load transfer of each soil layer was measured and compared with the previously developed existing model. The stiffness parameter (M) for the hyperbolic equation was calibrated in order to best match the measurements. The good agreement of the proposed curves was then confirmed by applying them to assess the overall load-settlement curve of other pile load test results available in the literature. INTRODUCTION The load transfer mechanism (stress-strain relationship) for an axially loaded pile usually comprises of three loading mechanisms: axial deformation in the pile (z), soil skin friction along the shaft (qs), and soil end-bearing (qb). The development of soil skin friction with axial deformation is referred as the t-z curve, and the development of soil end-bearing with axial deformation is referred as the q-z curve. Figure 1 presents the load transfer mechanisms in an axially loaded pile and the corresponding spring mass models for t-z and q-z curves (API, 2002). In order to construct the load transfer curve in clay under vertical load, the axial load transfer (t-z) curve and end-bearing load transfer (q-z) for that particular soil should be assessed separately. The axial load transfer (t-z) method is probably the most widely used technique to study the problem of single axially loaded piles. Therefore, the load transfer through the shaft of the pile and are getting more and more important compared to the only the pile capacity analyses. The load transferred from shaft to the surrounding clay soil is a function of the width of the pile and the surface roughness of the pile and clay properties. The development of a representative procedure allows the assessment of the t-z curve in soil (sand and/or clay) that leads to the prediction of a nonlinear vertical load-settlement response at the pile head.

Jan 1, 2018

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003

Sluice box operating practices in Papua New Guinea (PNG), and published work on sluice boxes are briefly reviewed. Some recent work on sediment entrainment mechanisms occurring in sluice boxes have also been described. In the light of this information, some drawbacks in the commonly adopted sluice box operating practices in PNG, and ways of overcoming them, are also highlighted.

Jan 1, 1991

By Almon F. Robertson

This report is one of a series based upon investigations made and being made within the Missouri River Basin in Montana by engineers of the Bureau of Mines , Albany Branch , Mining Division . These investigations are being made primarily to provide preliminary information to the Department of Interior agencies and to others concerned with planning the proposed Federal power developments within the Missouri River Basin. This report has been designed to permit public distribution of the factual data obtained . Virtually all known metallic -mineral occurrences and some nonmetallic mineral deposits within Fergus County were investigated in 1948. The investigations cannot be considered complete , however , because some long inactive mines or prospects may have been missed . Most of the old mine and prospect openings now are caved ; many are completely inaccessible . Many of the claims located years ago have been abandoned ; others have been relocated under different names and ownerships . Because of such conditions , much of the information regarding their development and operation necessarily has been obtained from available Federal and State publications , supplemented by information provided by owners and local residents .

Jan 1, 1950

By George A. Burrell, G. W. Jones, Frank M. Seibert

In this bulletin, the style of Bulletin 42 has been closely followed. Much of the material is reprinted on the following pages in its original form, and changes have been made only where manifestly neces- St,ry. Laboratory methods have been brought up to date. Some types of apparatus described in Bulletin 42 have now become obsolete and newer designs are described instead. The authors hope that this bulletin will be of as much service as was Bulletin 42.

Jan 1, 1926

By WILLARD W. CUTLER

This bulletin reviews, in the light of recent experience, the use of production-decline curves in estimating the future production of oil from wells. It deals with the estimation of the reserves of recoverable oil in properties already producing or in those adjacent to them, takes cognizance of the physical laws governing expulsion of oil from oil sands, and shows how the production-decline curve can be made to utilize these laws in estimating reserves and rates of production. The valuation of oil properties should be based on the total amount of oil recoverable from a property by the methods in use, the rate of recovery, the cost of production, and the selling price. Numerous other curves besides those for reserves and rates of production may be formed from the production-decline curve and will present desired information in a convenient time-saving form. These curves also are described. Methods developed before the production-decline curve method was used are briefly discussed in order that the principles on which estimations of oil reserves are based may be made plain. The construction of curves and tables for estimating future production of individual wells and of average wells in most of the important oil districts of the United States is described and operating problems that may be solved by the use of production-decline curves are discussed. The bulletin does not deal with costs, oil prices, or the methods of evaluating oil properties. Many engineers have amply demonstrated the value of the production- decline curve method by forecasting within reasonable limits the production of many thousands of wells and tracts. The value of similar estimates depends however, on (1) the application of trustworthy methods; (2) the care and judgment of the estimator; and (3) the length and reliability of the records and the accuracy of ofher information used in estimating future production. When adequate records and information are available, experience has shown that It qualified engineer can forecast production far more accurately than has been deemed possible, except where the usual conditions governing the expulsion of oil from a sand have been radically changed by applying compressed air or by flooding with water, or, to a less degree, by using vacuum. In general, the production-decline curve method, though there are limits to its accuracy, is far more trustworthy than any other.

Jan 1, 1924

Determination of Flotation Kinetics of Coal Grain Types in a Pilot Scale Jameson Cell using Coal Grain Analysis Method

Sep 13, 2010

By Ellsworth R. Spencer

An assessment of U.S. western hardrock miners? noise exposures was conducted as part of a multi-year National Institute for Occupational Safety and Health (NIOSH) survey of noise exposures in each sector of the mining industry. Noise from selected mining equipment and operator noise exposures were measured, analyzed and tabulated for dissemination to the participating sites and are being used to direct NIOSH research and interventions to address the greatest noise hazards. Eighty-two noise dosimeter measurements were obtained, along with time-motion studies as the miners operated hardrock mining machines. Of the operators, 96% had daily noise doses that exceeded the U.S. Mine Safety and Health Administration?s (MSHA) permissible exposure level. The average gold miner dosages while operating the following equipment were: haul trucks - 261%, load-haul-dumps (LHDs) - 235%, single boom drills - 221%, bolters - 214% and dual boom drills - 163%. The worst exposure level was a silver miner with a daily dose of 873%. Time-motion data showed that this miner?s exposure accumulated most rapidly while operating a jackleg drill. These results will be used to help prioritize noise control development by NIOSH and other partners.

Jan 3, 2010

By K J. F Logan, P W. Leaman, B A. Tucker

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Nam San copper-gold deposit was discovered in 2011 and is a likely blind extension of the Permian age Phu Kham structurally deformed porphyry/skarn copper-gold deposit.The Nam San mineralisation is hosted within a dominantly sericite altered schist unit located to the north of the current Phu Kham open pit operation and is overthrust by an allochthonous barren cover sequence of limestone, granite and sandstone. Reinterpretation of the Phu Kham geology developed the concept of a possible telescoped porphyry copper-gold system at depth. Initial drilling intersected remobilised copper mineralisation in a basal conglomerate, confirming the concept. A reconnaissance vector array induced polarisation (IP) survey identified a deep chargeability anomaly from which a drilling target was developed from 3D inversion modelling of a detailed follow up dipole-pole-dipole anomaly. Drilling of the chargeability anomaly intersected the blind Nam San copper-gold mineralisation beneath the thrusted cover sequence.The key discovery parameters are the result of an integrated exploration program that included reinterpretation of the local stratigraphy, which developed the concept of a deep blind orebody, IP surveys capable of penetrating through the barren cover and a commitment to a deep directional drilling program to test these concepts and targets. The inferred resource remains open at depth, and further assessment will most likely be through underground development.CITATION:Leaman, P W, Tucker, B A and Logan, K J F, 2015. The discovery of the Nam San copper-gold deposit, Phu Kham, Laos, in Proceedings PACRIM 2015 Congress, pp 515–520 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Paul Krivokuca

Outline Quinsam Coal Mine ?? Location ?? Mine History ?? Safety ?? Production ?? Hiring 4S Mine ?? Depillaring design ?? Structural mapping, Risk assessment ?? Rock Bolt Design Selection ?? Training

May 1, 2008

By Y R Fu, D R. Xu, C J. Wu, G C. Hu, H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Hainan Province (Hainan Island) in South China hosts numerous Mo-polymetallic ore deposits that are genetically related to Cretaceous granitoid intrusions. Laser ablation inductively coupled mass spectrometry (LA-ICP-MS) zircon U-Pb dating and molybdenite Re-Os dating reveal three metallogenic episodes: the late Early Cretaceous (ca 112 Ma), the late Early to Late Cretaceous (ca 95–106 Ma) and the Late Cretaceous (ca 72–89 Ma). The third mineralising episode might represent the youngest Mo mineralising event in East China. Results from this study demonstrate that Mo mineralisation on Hainan Island occurred under an extensional setting that was prevailing in the late Mesozoic (ca 180–67 Ma) in South China, which was likely due to the slab rollback of the subducted palaeo-Pacific plate beneath the South China continent.CITATION:Xu, D R, Hu, G C, Wu, C J, Fu, Y R and Chen, H, 2015. Geology and geochronology of the Mo-polymetallic ore deposits in Hainan Island, South China, in Proceedings PACRIM 2015 Congress, pp 645–648 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Charles Barnhart

This paper is a discussion of the causes of deflagration in cast blasting and a description of a project intended to demonstrate how changes in six critical parameters contribute to the deflagration chemical reaction. Control of these parameters is key to solving the nitrogen dioxide “orange smoke” problem. Preliminary results of an investigation into the development of a technology addressing the problem of atmospheric releases of nitrogen dioxide during cast blasting in surface mine operations are described. The project is funded by a $600,000 Small Business Innovative Research grant from the National Science Foundation and an $80,000 Abandoned Coal Mine Land Reclamation Program grant from the state of Wyoming. The presentation will address the measures required to control the blast chemical reaction so that it does not produce nitrogen dioxide through deflagration. Experimental blast data will be focused on a new shaped charge detonation system designed to instantaneously bring the powder column to maximum velocity of detonation (VOD), thus insuring efficient detonation of the entire colulnn.

Jan 1, 2003

By E. D. Gardner

From the standpoint of tonnage and dollar value copper is the most important nonferrous metal mined in North America. The opening of copper mines has had an important bearing on the development and settlement of many sections of the continent. The prosperity of many of the mining States or provinces depends directly upon the copper-mining industry. Normally, about 35,000 men are employed in the copper mines, mills, and smelters of the United States. The United States is the most important producer of copper among the nations; more copper is mined in North America than in any other continent, and for many years the United States alone produced about half of the copper of the world. During the last 10 years increasing production in South America and Africa has reduced the relative importance of North America and the United States.

Jan 1, 1938

By Robert W. Freedman

As part of a continuing effort to reduce the weight and bulk of equipment that mining personnel must carry underground, the Bureau of Mines and the Mining Enforcement and Safety Administration (MESA) investigated accurate and convenient gas samplers for use by mine inspectors in sampling mine atmospheres. The samplers are septum-stoppered glass vials commonly used for routine blood sampling. These lightweight, compact samplers yield results comparable with those obtained with conventional bottle samplers of 250-ml nominal capacity.

Jan 1, 1975

By Roberto L. Romero

The dressing of Bolivian tin ores has been done up to the present by classical. gravity methods, taking advantage of the high specific gravity of cassiterite compared with that of the accompanying gangue. For this purpose, jigs and shaking tables are used in the treatment of the various size fractions in which the ore is classified. Bolivian ores are mainly of the vein type and, to obtain a reasonable separation, crushing and several stages of grinding are necessary during the process to substantially liberate the cassiterite from the gangue. Gravity processes for cassiterite are effective for sizes down to 200 mesh. Below this size the efficiency of the gravity methods falls off very rapidly with increasing fineness of the mineral grains. The conventional treatment for this material is desliming followed by tabling on shaking tables various other types of machines have been designed for the gravity treatment of these fine particles but they have had limited success. Bolivian ores contain an appreciable amount of minus 200 mesh material constituted by "primary fines" caning from the mine itself, and "secondary fines" originated during the crushing and grinding necessary for liberation of the difficulty in the treatment of these fine particles is one of the causes why the recovery of tin in concentrates is only of around 50% in the mines owned by Corporacidn Minera de Bolivia, the State owned enterprise. The average figure for other Bolivian mines is

Jan 1, 1971

By Natália Caixeta Rocha

O Terminal Integrador de Santa Luzia (TISL) recebe materiais de origem siderúrgica (fio máquina, bobinas, fardos e chapas grossas) dos clientes Arcelor Mittal Monlevade, Aperam e Usiminas por via ferroviária e os armazena até que sejam despachados para os clientes finais, por via rodoviária. O fluxo inverso (recebimento rodoviário e escoamento ferroviário) é realizado para o cliente Gerdau (tarugos e vergalhões) e para o minério da Usiminas. Os fluxos ferroviários são realizados por vagões Gôndolas, GDE e Plataformas, os quais possuem um ciclo dimensionado para o atendimento ao volume orçado anual, sendo um importante indicador de performance para o TISL, assim como o ciclo de permanência rodoviária. Inicialmente, o tempo de permanência de vagões e carretas estava muito acima da meta determinada e, com o objetivo de reduzir o tempo destes ciclos, foi desenvolvido um projeto de aumento produtividade no terminal. O projeto teve como base a implantação da cultura TPS na busca pela melhoria contínua dos processos, juntamente com a estruturação apresentada na metodologia do PCDA, resultando em grandes ganhos em produtividade.

Aug 17, 2017

By Paulo Roberto Gomes de Sousa

O trabalho mostra a analise de energia e exergia de uma unidade termoelétrica, esta planta consiste em um ciclo regenerativo. Serão comparados os nivéis de irreversibilidade dos componentes que compõem a unidade. A escolha do ciclo regenerativo com a referência em análise, é devido sua eficiência global. Isso é proporcionado através do aquecimento da água de alimentação da caldeira, com isso, consequentemente ocorre uma diminuição da necessidade de energia imposta na caldeira. A análise realizada também mostra as irreversibilidades da planta através da análise de exergia.

Aug 17, 2017

By Clarence Hall, J. J. Rutledge

Many of the fatal accidents in coal mines have resulted from the Explosives used in Use of explosives for breaking down the coal. These accidents have resulted both from the use of explo- sives that were not suitable and from the careless or improper use of suitable explosives. Investigation has shown that one of the commonest causes of dis- astrous explosions in the coal mines in this country has been a blown- out shot of black blasting powder or dynamite. The dangers that attend the use of these explosives were perceived several years ago, and in consequence the attention of powder manufacturers was directed to the production of explosives that would be less liable to ignite inflammable gas or dust. The manufacturers have been so successful in their efforts that it is now possible to obtain explosives which yield much shorter and quicker flames than black blasting powder or dynamite, and hence are much less dangerous to use in fiery or dusty coal mines. of explosives. To find out which of the many grades of short-flame explosives Government tests have the qualities that render an explosive most effective and least dangerous for mining coal, the United States Government established a testing station at Pitts- burgh, Pa., in 1908. This station is now under the charge of the Federal Bureau of Mines. Before the station was opened a state- ment of the requirements that the explosives in question would have to satisfy was drawn up and sent to manufacturers. A number of these sent explosives to be tested, and on May 15, 1909, a list of the explosives that had passed the tests was published. Since that date other brands of explosives have been tested and three more lists have been issued. The latest list, published in Miners' Cir- cular 2, Bureau of Mines, contained the names of no less than 71 explosives that had passed the tests prior to January 1, 1911.

Jan 1, 1912

By Matthias Wörndl

A indústria siderúrgica demanda um acabamento superficial de excelente qualidade em placas (slabs), antes de seu processamento em laminadores. O limite da temperatura de fresagem de 300°C exigia um esfriamento com posterior reaquecimento, gerando elevadas perdas energéticas. A empresa austríaca Maschinenfabrik Liezen com ampla experiência na fabricação de fresadoras de grande porte até 300°C desenvolveu e fabricou uma revolucionaria fresadora de alta capacidade (600.000 ton/ano), para operar de forma contínua em 800°C; nesse desenvolvimento de hardware e software foram também incorporadas várias otimizações operacionais e ambientais, sendo o destaque a fresagem modulada/inteligente, com precedente relevamento topográfico e termográfico para a localização dos defeitos superficiais, para a posterior fresagem com profundidade variável para a minimização de material retirado e simultânea eliminação dos defeitos localizados.

Aug 17, 2017

By Breno Totti Maia

In the present paper, a new energy balance equation was developed, considering the slag phase, in order to define the effects of jet penetration and determine a new value for the factor K. The factor K measure the resistance to momentum transference between exit nozzle and metallic bath. The experiments were performed based on the same conditions of the article used as a comparison. The results showed the same behavior between the experiments and it was possible to determine a new value for the factor K, which changed from the unit order for the metal phase system to hundredths order for the metal and slag phase systems. These results are considered unprecedented.

Aug 17, 2017