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By Andrea Biagi, Elisa Comis, Gianluca Bella, Enrico De Panicis, Guido Barbieri, Matteo Giani

The Sotra Link Project is a major infrastructure project in Norway involving the design, construction, financing and maintenance of several underground and surface structures between Sotra island and the city of Bergen, among them 23 tunnel portals, 12.5 km of tunnels and a 900 m long suspension bridge. This paper describes the benefits in applying a Building Information Modelling (BIM) approach to tunnelling, from Early Design to the Detail Design Phase. The BIM application to the Sotra Link Project resulted in several improvements, such as efficient handling of clashes and inconsistencies, deeper understanding of effective design choices (reduction of errors), more efficient communication between designers, enhanced control of project quantities and costs. The advantages of the BIM approach during the ongoing Construction Phase are also explained.

Jun 23, 2024

By Ren G. Dong, Kristine M. Krajnak, Dan Welcome

Continual occupational exposure to vibrating hand tools can damage the neural, vascular and other soft tissues of the fingers. Rat tail models have been developed to investigate the biological responses of the tissues to vibration.1-2 However, the biodynamic response of the tail relative to that of the human fingers has not been characterized. The objective of this pilot study was to compare the transmissibilities of rat tails measured via a scanning laser vibrometer to those of human fingers gripping a handle. Methods In Part I of this experiment, four male Sprague Dawley rats (6 weeks old) were exposed to discrete 5g-rms sinusoids of 32, 63, 125, 160, 250, and 500 Hz. The rats were restrained in Broome-style restrainers with their tails constrained without compression to an exposure platform via elastic straps as shown in Figure 1. The platform was attached to a vertically vibrating shaker. The vibration was measured for the array of points shown in Figure 1 using a scanning laser vibrometer (Polytec) and the transmissibility calculated for each point on the tail relative to the reference points on the platform. In Part II, three male human subjects were exposed at the frequencies specified in Part I - with the addition of 1000 Hz - at a magnitude at the ANSI <0.5-hr limit up to 63 Hz, after which the acceleration was held constant at 5g-rms. The subjects gripped an instrumented handle at 20 N as shown in Figure 2. The transmissibility was calculated relative to the reference points on the handle. [ ]

Jan 6, 2006

Since mid-July, most domestic producers have been marketing 99.5 percent unalloyed aluminum ingot at 53-57 cents per pound. Dealers in the United States have recently quoted ingot at 52.3-52.8 cents. On October 2, London Metal Exchange will trade aluminum, selling contracts on a cash and a 3-month basis. New York dealers were quoting August ingot at 52.3 52.8 cents. The Bonneville Power Administration announced that, effective December 20. 1978, electric power rates charged primary aluminum producers in the Pacific Northwest would be increased The increase (equivalent to about 4 cents per pound of aluminum produced) will raise the average rate to about 8.7 mills per kw-hr compared to 3.2 mills per kw-hr.

Jan 1, 1978

By Edgardo Caro Orellana

El yacimiento Coroccohuayco fue descubierto durante el transcurso del segundo año de exploración (1971-1973) a través de un programa de Levantamiento Geológico del cuadriángulo Velli-Yauri, Cusco, considerándose como un ejemplo de prospección científica. En esta perspectiva, el objetivo del texto señala cuáles son los métodos de exploración empleados para dicho yacimiento. Entre los métodos del estudio regional tenemos la fotogeología, aeromagnetría y gravimetría y entre los métodos del estudio local están la geoquimiica, geofísica y perforación diamantina. Asimismo se menciona la prospección geofísica por el método de polarización inducida y la perforación diamantina.

Nov 20, 1978

By Andersan dos Santos Paula

O objetivo deste trabalho foi avaliar a influência da potência do laser Yb:vidro a fibra, no que diz respeito a extensão dos efeitos estruturais promovido e a possibilidade de corte de uma chapa de NiTi equiatômica austenítica com evidência de encruamento. Após a tentativa de corte a laser, a caracterização foi realizada através de microscopia óptica, microscopia eletrônica de varredura (MEV) / espectroscopia de energia dispersiva de Raios X (EDS) e análise de nanoindentação instrumentada. De acordo com os resultados obtidos pode-se observar que nenhum dos parâmetros de corte a laser usados nos 3 cortes distintos foi suficiente para promover o seccionamento da chapa, bem como revelou evidências de recristalização em conjunto a uma significativa oxidação superficial na zona termicamente afetada.

Aug 16, 2017

By Jefferson Haag

A análise da estampabilidade de chapas metálicas consiste em ensaios e testes tecnológicos para obtenção de características específicas para os processos aos quais o material será submetido. Dentre as principais análises, pode-se destacar o ensaio de tração, a curva de escoamento e o índice de anisotropia, que fornecem dados a respeito do comportamento mecânico dos materiais, como a resistência, a ductilidade, o encruamento, entre outros. O presente trabalho tem o objetivo de avaliar a estampabilidade dos aços carbono AISI 1008 e AISI 1010 através dos ensaios de tração, ensaios para determinação da curva de escoamento e ensaios para determinação do índice de anisotropia. Para tanto, foram extraídos corpos de prova de chapas dos dois aços de baixo carbono, seguindo as normas ASTM E8/E8M e ASTM E517, para realização e análise dos resultados dos ensaios. Com base nos resultados obtidos, pode-se aferir que o aço 1008 possui maior ductilidade e melhores características anisotrópicas do que o aço 1010, que por sua vez apresenta maior resistência mecânica. Portanto, é possível concluir que o aço AISI 1008 apresenta melhor estampabilidade a partir de todas as propriedades adquiridas nos ensaios mecânicos.

Oct 30, 2017

By Willy Ank de Morais

A Norma Regulamentadora 18 (NR 18) requisita que o trabalho em telhados e coberturas devem ser efetuados com uso de dispositivos dimensionados por profissional legalmente habilitado e que permitam a movimentação segura dos trabalhadores. A forma tradicionalmente mais segura de locomoção em telhados e coberturas é através de passarelas, que devem ser adequadamente fixadas à estrutura destes. Neste trabalho foram dimensionados e fabricados componentes de alumínio para a fixação mecânica de plataformas-escadas em alumínio. Estes componentes foram adequadamente soldados às plataformas de forma a obter um produto final mais seguro e adequado às operações de manutenção de telhados, especialmente em galpões metálicos de grandes proporções, como foi o caso dos galpões onde este produto foi empregado pela primeira vez.

Oct 30, 2017

By Nathaneal Williams, Corby Anderson

Rare earth elements are in high demand in the USA. Bastnaesite, a rare earth fluorocarbonate containing primarily cerium and lanthanum, is one of the most abundant sources of rare earths in the USA. This research was completed using the ore from Mountain Pass, which is the largest rare earth mine in the USA. This research, resulting in a current patent application, was done to find a way to combine flotation with novel collectors and gravity separation techniques to reach an enhanced grade and recovery of rare earth elements while rejecting the gangue minerals, calcite, barite, and silicate minerals. These minerals, particularly calcite, an acid consumer, are well known to be difficult to separate in conventional flotation of bastnaesite ore. Four collectors were examined. They were N,2-dihydroxybenzamide, N-hydroxycyclohexanecarboxamide, N,3- dihydroxy2-naphthamide, and N-hydroxyoleamide. Through this analysis, it was determined that, to obtain the desired results, flotation would be the rougher stage and gravity separation would be utilized as the cleaner stage. Bench scale flotation tests were conducted on the run of mine ore using conditions that were determined using a previously utilized Stat Ease model for testing and statistical optimization in design of experimentation. The bench tests that produced the most desirable results were then scaled up to a 10 kg float test. A concentrate from this test showed a rare earth oxide grade of 44%, while rejecting 91% of the calcite. This concentrate was used for gravity separation. Through gravity separation, it was found that another 40% of the calcite could be rejected with a final rare earth oxide grade of 47% in the concentrate.

Apr 1, 2024

By Davi Silva Braga, Alexssander Lopes Sampaio, Rodrigo Carneiro de Oliveira

Vallourec was world pioneer in the deployment, development and consolidation of technology for the use of pulverized charcoal as the main energy source on the first Grate-kiln pelletizing plant in Brazil. The objective of this work was to delve into the subject and to bring more information about this innovative practice of Vallourec that has been attracting the attention of other companies in the steel industry. Industrial tests confirmed the technical feasibility, taking Vallourec ahead in the project of adaptation and investment. With consolidated data of two years and five months from the beginning of the implementation, the main benefits are the average reduction of CO₂e emissions by 50%, cost reduction higher than expected and return on investment in just 19 months.

Oct 1, 2019

By Charles E. Robertson

As it becomes more and more apparent that our nation must place a great deal of reliance on coal as an energy source in the coming decades, prospecting for new reserves Un Missouri and other states in the Western Interior Region is increasing. As more and more of the known reserve becomes committed to existing or planned projects operators will be forced to look beyond the fringes of existing coal fields for additional reserves. Perplexing geologic problems invariably confront all prospectors and are particularly bothersome to those new to a particular area. It is the purpose of this paper to alert prospective operators to geologic problems likely to be encountered and to offer guidance in the recognition and solution of these problems. Particular emphasis is placed upon geologic structure and washouts. Other geologic problems have been discussed in a previous paper.

Jan 1, 1977

By E. R. Bauer

The trend in underground room-and-pillar coal mining is to employ remote-control continuous mining machines and extended cuts, 12 m (40 ft) deep or more. This system of coal extraction, adopted by over 435 mines, can create additional worker-safety hazards. To address the ground control and worker-positioning hazards, a combination of statistical analyses and numerical modeling was conducted. Initially, the reported roof-fall incidents and fatalities were reviewed to delineate the ground-control hazards. Then, the application of the Coal Mine Roof Rating (CMRR) for estimating safe extended-cut depths was evaluated. Finally, computer modeling to predict roof displacements during extended-cut mining was completed. The paper describes the results of these studies and their impact on the safety of extended-cut mining.

Jan 1, 1999

By Arthur Notman

Since addressing the Institute a year ago on The Future of the Copper Industry (l), many things have happened, most of them bad. It has been a hard year for profits and prophets. It was, therefore, with consider-able perturbation that I accepted the gracious invitation of your Committee to reappear. On reviewing my remarks of a year ago, I. have wondered whether, under pressure of more important matters, the Committee had neglected to make a note of them, or whether they felt that further explanations from me were in order. In either event, I am glad that I am here and welcome the opportunity to make any contribution I can to a clearer understanding of the problems of copper to those concerned. The English-speaking nations own 80 per cent of the present world-production of the metal. Col. P. E. Barbour, Secretary of the Mining and Metallurgical Society of America, and I recently completed an estimate of the known world resources of copper. We placed the figure, in round numbers, at 100,000,000 tons of metal. Of this amount, about one-third lies in the United States, one-third in the British Empire, and one-third in South America; and all but 4 per cent of this is owned by British Empire and United States capital. Our figures do not include any estimates for Russia, Japan, or Europe, on which there are no available data. It is true, consequently, that the British Empire and the United States are the ones concerned. It seems to me to be a matter of great importance to the world at large, and of even greater importance to those nations themselves, that the known sources of supply of this metal, so essential both in peace and war, rest so strongly in their hands. I cannot believe that in the long run they will neglect their responsibilities in the wise administration of these resources.

Jan 1, 1932

By S M. Denn

The Cawse nickel-cobalt operation is situated 50 km NW of Kalgoorlie in Western Australia, at latitude30o22&apos;30&apos;&apos; south and longitude 121o08&apos;30&apos;&apos; east on the Kalgoorlie 1:250 000 geological map sheet (SH 51-9) (see Figure 1). The project is owned and operated by Centaur Nickel Pty Ltd (CTR) and was the first in Australia to commercially produce nickel metal and cobalt sulphide through pressure acid leach (PAL) technology. Cawse has a total resource base (all categories of resources + reserves) of 213 million tonnes Mt at 0.7 per cent Ni and 0.04 per cent Co, comprising 127 Mt at Cawse Central which is 100 per cent owned by CTR and 86 Mt at Cawse Extended where CTR has a 80 per cent equity. Cawse Extended is located immediately to the northwest of the Cawse Central leases. All current reserves (proved and probable) of 30 Mt at 1.0 per cent nickel are contained within Cawse Central. In addition the Siberia project area 20 kilometres to the NW has a resource of 63 Mt at 0.7 per cent Ni. Cawse is a dry laterite deposit, with nickel and cobalt hosted by iron and manganese oxides. Cawse Central mineralisation extends over a ten kilometre strike length, with three pits currently being mined. The Bunyip pit has the premier nickel and cobalt grades within Cawse Central. There are seven dominant lithology types forming mappable units within current pit exposures. Four of these units are host to nickel and cobalt mineralisation. Ore types are defined as Upgrade, Grind and Non-upgrade, depending on their physical characteristics with respect to the treatment route. Mining commenced in February 1998. To the end of calender 1999 the operation has produced 2100 tonnes nickel plate and 470 tonnes of cobalt as a cobalt sulphide product. Future production will target 9000 tonnes per annum Ni metal and up to 2000 tonnes per annum Co, based on processing 500 000 tonnes of ore per annum.

Jan 1, 2000

By Peter Faust, Peter Hubbard, Kenichi Soga

The European Federation of Foundation Contractors (EFFC) and The Deep Foundations Institute (DFI) have set up a task group to compile a Guide for Working Platforms. The first edition of this Guide has been published in January 2020. The aim of the Guide is to provide reliable methods for design, testing and verification of working platforms for construction equipment, especially in the deep foundation industry where track loads can be excessive due to the nature of its operations. The Guide has identified areas where knowledge is limited. Actual track pressure and its distribution along the length of the tracks is still not well researched. Current recommendation provided in EN 16228-1 are believed to be overly simplified and may lead to conservative requirements for working platform thickness. This paper presents results of a series of field tests where the actual track pressure of a large drilling rig during operation was measured in real time together with the deformation of the working platform. Embedded, distributed fiber optic sensing (DFOS) at different depths throughout the platform allowed for a three-dimensional evaluation of the platform deformation throughout the entire operation. Results will help to develop more reliable recommendations for future safety requirements of working platforms for deep foundation equipment.

May 1, 2022

By H. Wotruba, L. von Ketelhodt, M. Kowalzcyk, M. Robben

ABSTRACT Decreasing reserves, water shortages, increasing energy costs, and environmental and social constraints are challenges to the gold mining industry that must be met with innovative machines and methods. This paper introduces the principles of sensor-based sorting and installations that demonstrate the technical and financial viability of the method. The scenarios discussed highlight the potential and advantages of this dry processing technology that requires little infrastructure. Case studies are presented for different ore types using optical- and X-ray transmission–based sorting. Current research is discussed in terms of the potential of near-infrared spectroscopy and X-ray fluorescence sorting for gold applications.

Jan 1, 2013

By Eugene H. Skinner

The 7-mile Flathead Tunnel, located in the central Salish Mountains of northwestern Montana, was constructed between 1966 and 1969, With the contract awarded April 19, 1966, drill and blast tunnel excavation began September 30, 1966, and was completed June 21, 1968, in 488 tunnel-driving days, Peak advance was 66 feet per day. On June 27, 1969, all tunnel concrete lining was completed. Average wall and arch concrete placing rates exceeded 1,700 cubic yards daily, with nearly half of the concrete placed during a severe winter season. Major cost savings in concrete tunnel lining were achieved through a value engineering clause in the contract. Achieving consistent results and high rates of placement in concrete lining ranked equal to ground control in overall tunnel problems. Ground control problems exceeded expectations and were of continual concern throughout excavation, One support collapse in the tunnel and one portal slide condition developed during construction. Critical surface geologic exposures were largely obscured; only a portion could be accurately projected underground, An instrumentation program to gather basic data on rock defamation near the heading face for support purposes was a pioneering effort. The Flathead Tunnel was placed in service on November 7, 1970.

Jan 1, 1974

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982

By Kazem Oraee-Mirzamani, Nikzad Oraee-Mirzamani, Arash Goodarzi

"Unexpected movement of ground can potentially endanger lives, damage equipment or destroy property. Occupational accidents frequently occur with fatal consequences in developing countries with significant economic dependence on industries such as mining. Therefore, there is increasing need for miners' protection against such hazards. Slope stability and roof support accidents are two of the major causes of fatalities at surface and underground mining operations. According to national codes, employers are obligated to protect workers against accidents; however, these rules fall short of the standards in developed countries. National safety regulations should clearly specify support systems. The International Labor Organization (ILO) prepared two codes of practice, aiming to guide those responsible for improving standards of safety and to provide guidelines for drafting of safety regulations for the coal mine industry and quarry open cast mines. The practical recommendations of these codes in the ground control area have been analysed and the advantages and disadvantages of ILO codes concerning ground control are summarized.INTRODUCTIONTwo million people die every year from work-related accidents and diseases. An estimated 160 million people suffer from work-related diseases, and there are an estimated 270 million fatal and non-fatal work-related accidents per year. In economic terms, the ILO has estimated that 4% of the world's annual GDP is lost as a consequence of occupational diseases and accidents (ILO, 2009).Mining has always been dangerous due to many potential risks such as those associated with using machinery in enclosed spaces, rock falls, blasting operations and explosion of flammable gases, which endanger miners' safety and health. However, it is suggested that implementing new laws along with strict adherence would reduce such risks in the workplace.The severity and frequency of accidents are trending downward in developed countries, where the focus is on large private companies who invest heavily in mechanization and developing economies of scale. But in many parts of the world, particularly in developing countries, minerals are extracted by people working with simple tools and equipment; they work on a smaller scale, are more flexible, and can exploit irregular ore bodies and steep, dipping seams."

Jan 1, 2010

By Bruno Miotto, Rômulo Faria, Juliano Tessinari

Water has become a scarce resource in quality. Companies in the ornamental stones sector use water intensively in their processes. Given the current situation, it is imperative to rationalize this feature that at first is related to the reduction of consumption, through no waste. Considering the importance of environmental preservation of this resource and also to comply with the legislation that governs the procedure for processing of ornamental stones, new alternatives should be available for the maintenance of current activities and promoting the development / growth of the sector on the principles of environmental sustainability and economic in future scenarios. The ornamental stones processing industries, especially for micro and small enterprises, require the implementation of a management program that optimizes the use of this feature, since the techniques individually processed operate with three basic processes dependent on water use: split blocks, polishing and finishing slabs. This technology requires a large volume of water resources and control measures involving operating recirculation water can minimize power consumption, making the company more profitable and sustainable. This is a survey of literature, associated with technical reports provided by partner companies and government agencies. This study aimed to the organization and provision of theoretical knowledge about the subject matter coupled with management practices, which may be reproduced or re-purposed in ornamental stones processing companies. It should be noted that the industry in question is lacking in technical expertise for the implementation of sustainable attitudes relevant to water reuse.

Jan 1, 2014

By Pedro Lilienfeld

This report describes a program whose objective was to develop, design, fabricate and laboratory-test two prototype instruments capable of real-time selective detection and measurement of airborne fibrous-shaped particles. The operation of this fibrous aerosol monitor (FAM) is based on the rotation imparted to the acicular particles by means of a rotating quadrupole electric field of the order of 3000 V/cm. This field induces a dipole charge separation on the fibers and aligns them with the applied field. The selective detection of the fibers is effected by synchronous detection of the resulting modulation of the light scattered from a continuous-wave helium-neon laser beam by the rotating particles. The theory of operation, design of the electric-optical detection configuration and the electronic signal processing method are discussed. By means of a scattering pulse sharpness discrimination technique, fibers whose length exceed a selectable value are detected and their number concentration digitally displayed. Counting times of 1 to 1000 minutes permit the measurement of fiber concentrations between 0.001 and about 30 cm-3. A concentration of the order of one fiber per cubic centimeter can be assessed within a relative standard deviation of 10 percent with a counting period of 10 minutes. The FAM is a portable, battery-powered instrument capable of operating continuously for about 4 hours between battery charges. Preliminary tests with crocidolite and crysotile asbestos as well as with glass fibers were performed in the laboratory and the results indicate good correlation with the standard NIOSH phase contrast microscopy filter counting method.

Jan 1, 1977