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By Claudio Olalla

This paper relates to the foundation of a steel structure located at the San Martin de la Vega (Madrid) amusement park. The structure has more than 100 supports with various loading conditions, including important horizontal and uplift forces. Additionally, the settlement tolerances are very strict. A massive gypsum formation with interbedded clay layers and random solution great voids at various levels constitute the soil. The foundation design has been conditioned large enough these difficulties (load conditions and soil problems). The piling machine used was powerful to drill through the soft rock (UCS up to 11Mpa). The integrity of each pile had to be guaranteed by continuous recording of drilling and concrete pouring parameters. In order to fulfil all those conditions, a STARSOL type-piling rig was used. More than 4500 meters of piles were performed. The diameters of the piles were 450 and 550-mm and their depths varies from 6 to 23 meters. All piles were reinforced over their full length.

Jan 1, 2002

By Roberto Folchi

This note deals about the controlled demolition work for the dismantling of an industrial structure in San Seplocro, Italy. The structure to be demolished, the FLOWERS SILOS, consisted in a multilevel reinforced concrete frame supporting r.c. silos and steel silos. This was standing near civil buildings and was adjoining a warehouse that had to be safeguarded for being renewed.

Jan 1, 1994

By Wilson Acchar

The accelerated growth of urbanization processes and current environmental concerns brought to light the existing enormous quantity of construction and demolition waste (C&DW). Considering the frequent lack of adequate landfill areas available for the disposal of these materials, their use in the manufacture of ceramic products has been attracting a growing interest from researchers and is becoming common practice, with the consequent relief in public administration concerns for the C&DW appropriate management. This work describes the study of clay-based products added with C&DW collected directly from the construction industry. Samples containing up to 50 wt.% C&DW were uniaxially pressed and sintered in air in an electric furnace (950-1150 °C, 1 hour). Sintered test pieces were characterized by X-ray diffraction, apparent density, open porosity and flexural strength. The results showed that up to 50 wt.% C&DW can be added to the clay material, with no degradation in the final product properties.

Jan 1, 2009

By Steve Kral

In the United States, the U.S. Environmental Protection Agency (EPA) is set to implement its Tier 2 air quality standards governing high-horsepower, off-road diesel engines. The regulations take effect in January2006. In Europe, similar standards, called Stages, are due to take effect about the same time. And other markets, such as Japan and Australia, have their own standards on tap. Tier 2 standards will further reduce the amount of nitrogen oxide (NOX), sulfur dioxide (SO2), diesel particulate matter (DPM), carbon monoxide (CO) and hydrocarbons off-highway diesel engines are allowed to emit. And even more restrictive Tier 4 standards are due in 2011. The upshot is that operators of high-horsepower engines, particularly in mining, will begin using in their new off-road haul trucks, excavators, shovels and other mining machines diesel engines that are designed to meet these more stringent standards.

Jan 1, 2004

By Ira Sohn

This article revisits global projections made in 1981of eight metallic and fertilizer minerals for the year 2000. The objectives here are to quantify the differences between the projected and observed levels of consumption for the year 2000 for eight of the 26 nonfuel minerals covered in the earlier study. An attempt is then made to attribute these (often) large differences to the major determinants of minerals demand — income, technological, regulatory and other policy changes, and changes in the recycling rates of the metallic minerals. The eight minerals covered are aluminum, copper, iron, mercury, nickel, phosphate rock, potash and tin. This summary article presents the actual population, gross domestic product (GDP) and per capita GDP changes from 1970 to 2000, compared with the projected rates for these important determinants of mineral use, along with the observed growth rates of minerals consumption for the eight nonfuel minerals included in this study. When the projections are compared with the observed global consumption levels for the year 2000, the differences range from +43 percent for nickel to +229 percent for potash.

Jan 1, 2005

By Fabrice Mathieu

The Cutter Soil Mixing (CSM) provides a cost effective solution for the rapid construction of retaining and cut-off walls using new equipment developed from diaphragm wall cutter technology. CSM consists of cutting and mixing drums mounted on compact hydraulic motors. Soletanche Bachy CSM has been designed to leave the space above the tool free, thereby mixing the soil efficiently during all the phases of the wall construction, with high penetration rates. The precise positioning and verticality of the wall is achieved using a kelly bar and full monitoring. Soletanche Bachy CSM is a versatile equipment which can be mounted on various carriers: pile rigs, hydraulic crane, carrier equipped with telescopic mast. The major phases of Soletanche Bachy CSM development are presented, including the results of an extensive trial carried out in Le Havre (France). The soil consists of hydraulic fill with soft soil lenses overlying sandy deposits. 20m deep panels were constructed to support a rectangular shaft. During the construction, and after its completion, the shaft was subjected to an extensive series of tests followed by a partial excavation. The paper discusses also the future development of the technique and its potential applications.

Jan 1, 2006

By A. Boominathan

The behaviour of single piles under lateral dynamic loading is very critical and the study is still a current field of research since 1950's. Though many methods have been developed analytically to estimate the dynamic lateral stiffness, very limited dynamic testing on full scale piles were carried out to study the response of piles under lateral dynamic loading. Hence, field lateral dynamic vibration tests are conducted on driven precast concrete square pile of 400mm size and driven cast in-situ concrete piles of 400mm and 500 mm diameter at a petrochemical complexes site at Haldia (India). The results of steady state and free vibrations tests are discussed herein and compared with the response of the piles estimated from PILAY.

Jan 1, 2002

By J. Forwood

The Youga gold mine in Burkina Faso, West Africa, is scheduled to produce first gold in the third quarter of calendar 2007. The project is expected to produce 540 000 oz of gold over 6.5 years, from a conventional open pit carbon in leach mine. The direct capital cost of the project is US$47 M. Etruscan Resources Inc, a Canadian based gold exploration and development company, holds 90 per cent of the project company Burkina Mining Company SA (BMC). The state of Burkina Faso is free-carried for the remaining ten per cent of BMC. RMB Resources Limited, of Melbourne Australia, has arranged a US$35 M project finance facility for BMC (the Borrower) as the majority of funding for the Youga project development. The loan facility was provided by RMB Australia Holdings and Macquarie Bank Ltd (the Lenders) each as to 50 per cent in the lending syndicate. The Lenders also provided a gold hedging facility to guarantee a minimum price for the project's gold production. Burkina Faso is a francophone country, part of the Economic and Monetary Union of West Africa (UEMOA). The project financing is the first such facility to be arranged for a mining project in Burkina Faso, with little or no precedent available in other UEMOA countries. Therefore, while the Youga gold project is forecast to be a robust project applying conventional mining and processing methods, a number of legal, technical, commercial and social issues required identification, evaluation and resolution before the loan could be established. This paper describes that evaluation process and the resolution of these issues. In-house experience and expertise in both the Lenders' and Borrower's teams has facilitated a greater understanding and `ownership' of the issues and hence provided comfort with risks which might not normally be taken in conventional project developments and project financings. As a result, blanket external reviews were not required by the Lenders. A long-standing relationship between Etruscan and RMB Resources also facilitated solutions to a number of issues. Nevertheless, a degree of flexibility by the Lenders, the Borrower and Etruscan was required to successfully close the financing.

Jan 1, 2007

By M. Lohk, Y. -. R. Pastarus

Oil shale industry of Estonia provides a significant contribution to the country’s economy, but causes a large number of different problems. In spite of high economical parameters of the current underground mining (room-and-pillar) technology it is not effective. Backfill technology will be applicable in condition of Estonian oil shale mines. Nowadays attention has been focused on the use of combustion and mining by-products as filling materials. Use of ash and limestone in mining industry is treated as a part of mining technology, not as a waste disposal. Underground utilization of wastes reduces the volume and area required for surface disposal, environmental taxes. It improves the quality of mining works. The use of backfill technology has great impact on mining practice in Estonian oil shale industry.

Jan 1, 2011

By Allen McComas, Frank Chase, Phyllip Worley

Longwall mining has gained the reputation as being the safest extraction method in underground coal mines. However, one of the most difficult tasks associated with longwall mining is moving the face once a panel is completed. Based on Mine Safety and Health Administration (MSHA) fatality reports since 1996, longwall face recovery operations have claimed the lives of 5 U.S. miners and have resulted in numerous injuries. Recovery operations can be hazardous because they involve moving large pieces of equipment in very confined spaces. They are also conducted in highly stressed ground conditions due to front abutment loads generated by panel extraction. Shield removal is the most hazardous operation during face recovery because miners are constantly exposed to the unpredictable gob edge. To protect the miners, one or more walking shields, cribbing and/or other supplemental roof and standing supports are typically employed as breaker line supports as each shield is removed. At the Harris No. 1 Mine in southern WV, mobile roof supports (MRS’s) have been used in lieu of traditional walking shields on 17 face moves since 1997. MRS’s are shield-like support units mounted on crawler tracks and are commonly used during room-and-pillar retreat mining operations. For longwall recovery, the two biggest advantages that MRS’s have over traditional walking shields are that they are remotely controlled and are highly maneuverable. MRS’s have contributed to safer shield recovery and shorter move times at the Harris No. 1 Mine. This paper will address both the safety and the operational issues associated with MRS usage during shield recovery. It will also discuss new developments, including the use of the inherently safer battery powered MRS’s, which have been recently certified by the Mine Safety and Health Administration.

By T. Güyagüler, A. Güngör

Labour protection, that is prevention of occupational disease and reduction in the frequency of accident, has always been a matter of major concern of mining industry. Management and the government should promote and maintain high safety standards through some measures to reduce accident frequency and occupational disease. This can be achieved by using the science and technology for improving the working conditions, educating workers and managers about accidents and prevention techniques. The detailed analysis of an accident requires knowledge of many factors such as location, time, type, cost of accident, victim, nature of the injury, personal and environmental factors etc. that can be obtained from the standard coded accident report form. There is a need to prepare safety data in a common format to produce a common safety reporting system and ‘Occupational Health and Safety Management Tool’ is being designed to manage this by using database and Internet technology. Precautions should be taken according to results from database queries by providing comprehensive and accurate national data. To have an accident is unfortunate, however, to have an accident and learn nothing from it is unforgivable. Keywords: Occupational health and safety, Accident report form, Accident database, Occupational diseases and accidents, Safety reporting system.

Jan 1, 2003

By David K. Ingram

Research performed by the U.S. insurance industry has determined that mine subsidence is uninsurable. Consequently, the insurance industry has decided not to voluntarily offer mine subsidence insurance. The U.S. Department of the Interior has long been investigating the effects of mine subsidence. These investigations have resulted in Federal regulations and controls of mine subsidence. This U.S. Bureau of Mines report generally describes mine subsidence, the development of mine subsidence insurance programs, and the eight current mine subsidence insurance programs in the United States. The States that have these subsidence programs include Colorado, Illinois, Indiana, Kentucky, Ohio, Pennsylvania, West Virginia, and Wyoming. Major aspects of the programs include history, administrative and operational procedures, insurable structures, recognition of mine subsidence, major exclusions, claims, insurance premiums, and the economic health of each program. Addresses of agencies involved with mine subsidence insurance are also given. Information within this report can be useful for residential and commercial property owners and mine operators. States that are considering starting or have an existing mine subsidence insurance program can also use this report as a model for initiating or modifying their programs.

Jan 1, 1993

By Alan D. Hartman

The U.S. Bureau of Mines, under a Memorandum of Agreement with the American Society of Mechanical Engineers (ASME), established design criteria for a facility to melt residues from municipal waste combustion. This facility, which is available to potential users on a cost-sharing basis, is also applicable to a variety of inorganic waste materials from smelting or melting operations. The design consists of a mechanical feed handling system, electric arc melting furnace, fume-offgas handling system, and thermal oxidizer for final offgas treatment. Screw conveyors and a bucket elevator deliver up to 2,000 lb/h of minus I-in material to a three-phase electric arc melting furnace. This unique 800-kV?A furnace has a water-cooled shell and roof to minimize interaction of the melt with the refractory lining. The volume of the hearth below the slag taphole is approximately 1.2 st of steel. The furnace is sealed, allowing atmosphere control within the furnace and fume duct by nitrogen or inert gas injection. A jet-pulsed baghouse removes particulate from the offgas and serves as an acid gas scrubber. The clean offgas is heated to 1,800° F for 1 s in a propane-fired thermal oxidizer before being vented to the atmosphere.

Jan 1, 2010

By S. Parada, P. T. Jones, M. Guo, S. Smets

The corrosion behaviour of a high-quality rebonded magnesia-chromite refractory in contact with a vacuum oxygen decarburization (VOD) slag with high Al2O3content (15?20 mass per cent) is investigated under VOD process conditions by rotating finger tests in a vacuum induction furnace. The refractory degradation mechanisms are studied by the characterization of corroded microstructures using scanning electron microscopy, equipped with energy dispersive spectroscopy. The influence on the refractory wear of the process temperature and the Al2O3content in the slag is discussed. Keywords: corrosion, magnesia-chromite refractory, VOD slags, vacuum induction furnace

Jan 1, 2004

By James J. Anderson

In this talk I will report on an effort to reassess the risk of pile driving to juvenile salmonids migrating through Puget Sound. The study was motivated by the concern of the construction industry that provisions restricting pile driving during the spring migration is resulting in an unbalanced burden to the industry. In simple terms the industry wants to know if some construction can be conducted in the spring without harming the juvenile fish. Fisheries agencies have agreed to reconsider their regulations in the context of additional studies. So, in this talk I will present some thoughts on risk assessment in general and the results of our study to assess the impact of pile driving on Snohomish River juvenile pink and chum salmon that migrate through the Navy Homeport construction site at Everett. The research, which is being carried out by the Fisheries Research Institute at the University of Washington, was planned and is supported in a joint effort including: the Washington Department Fisheries, National Marine Fisheries Services, U.S. Fish and Wildlife Service; General, Manson, and Hurlen construction companies, the Department of Transportation and a number of Puget Sound ports authorities. I will first briefly discuss the early life history of the juvenile salmon the regulations are designed to protect Second, I will outline the legal criteria required for risk regulation and some specific thoughts on how a reassessment of pile driving risk might be approached. With this basis I will report on our research and how it can be applied to a new risk assessment.

Jan 1, 1990

This Technical Memorandum Report is a collection of three working memoranda, prepared during the course of our work for the bureau of Mines and hound together for convenient reference. These working memoranda present preliminary performance estimates, for baseband voice and narrowband through-the-earth electromagnetic communications systems of principal interest to the Bureau, for operational/emergency mine communications. The calculations were prepared to obtain early indications of the feasibility and governing parameters of such communications systems. They are based on limited, but pertinent, coal mine electromagnetic noise data acquired to-date by Bureau of Mines contractors; and of theoretical signal-attenuation characteristics for two transmitter antenna types of present interest to the Bureau. The memoranda examine the cases of baseband voice and narrowband communications for uplink and downlink transmissions, for frequencies up to 3kHz. Downlink transmissions are via a horizontal wire antenna, up-link transmissions via a vertical-axis loop antenna, for typical mine depths of 300, b00, and 1000 feet. Representative coal-mine overburden conductivities of 10-2 mhos/meter (moderate and common) and 10-1 mhos/meter (high) were used; 10-2 for voice and narrowband, 10-1 for narrowband only. Examples of high, moderate, and low; surface and subsurface; harmonic and broadband-impulsive noise conditions were taken from NBS and Westinghouse (WGL) mine noise data, together with examples of high- and low-levels of ELF atmospheric noise taken from M.I.T. Lincoln Laboratory data.

Jan 1, 1972

By M. Didyk

In this report, the application of the PHU/MVS program is demonstrated through the use of a simple but realistic mine ventilation program. The report details, the problem description, the input data required and the various output features of the simulator. The PSU/MVS program is written in Fortran IV for use with IBM 370/168 computers. A version of the program that can be used in CDC computers is also available. A ventilation network consisting of 531 branches, 300 nodes and 5 fans took 48 seconds for solution on The Pennsylvania State University's IBM 370/168 computer. Appendix I of this report is the User?s Manual for the program. Appendices II and III contain the input data listing, and selected output listing for; the application. Appendix IV provides tables for leakage, friction factors and shape factors.

Jan 1, 1977

By Kenneth Gavin

The accurate prediction of the shaft capacity of drives piles in sand continues to present problems for foundation designers. Research in this field has been carried out for many years and has yielded a wide range of design approaches -some of which have been shown by recent experimental work to be based on questionable assumptions. This Paper reviews some of the current popular design methods for piles in sand in the context of recent information obtained from high quality field tests conducted by institutions such as Imperial College London. A database of driven piles in cohesionless soils has been compiled from well documented (and reliable) case histories that have been reported in the literature. The measured shaft capacities of the piles in this database are compared with predictions made by the various methods and an assessment is made of the predictive performance and reliability of each method

Jan 1, 1996

By Wu Xueling

9K medium was used to isolate iron-oxidizing bacteria from 27 sump water samples collected from Dexing Cop-per Mine, Chengmen Mountain Mine and Yin Mountain Mine, Jiangxi Province, China. Lead acetate and silver nitrate were used to enrich metal-resistant iron-oxidizing bacteria from the above water samples. Isolate 16 was isolated from the sample taken at Dexing Copper Mine. Growth experiments indicated that when incubated under lead acetate (3,500 mg/L), isolate 16 still carried out ferrous ion oxidation, while isolate H1, a less resistant strain taken at Yin Mountain Mine, had a tolerance level of only 400 mg/L. When assayed with other metals, i.e., Ag+ (240 mg/L), Hg2+ (0.9 mg/L), Cu2+ (32,000 mg/L) and Mg2+ (22,500 mg/L), isolate 16 still carried out ferrous ion oxidation while, on the other hand, isolate H1 exhibited much lower tolerance levels, i.e., Ag+ (60 mg/L), Hg2+ (0.1 mg/L), Cu2+ (19,000 mg/L) and Mg2+ (13,500 mg/L). Based on 16S rDNA sequence data, isolate 16 and H1 were both identified as Acidithiobacillus ferrooxidans.

Jan 1, 2007

By Rick Coleman

PT Freeport Indonesia’s (PTFI) latest expansion has increased total mill throughput to 125kt/d (137,700 stpd). The most recent expansion included the installation of a semiautogenous mill (SAG) designed to treat more ore than any other single SAG mill currently operating in the world. Also included in the expansion were two large ball mills, rougher and cleaner flotation, including conventional and column cells, and a regrind circuit. All equipment is supported by a modern distributed control system. PTFI’s operations are located in the Ertsberg mining district of Irian Jaya’s Jayawijaya Mountains, the eastern-most province of the republic of Indonesia on the Island of New Guinea. PTFI, the operator, is owned by Freeport McMoRan Copper and Gold (81.3%), the government of Indonesia (9.4%) and private Indonesian investors (9.3%).

Jan 1, 1996