Search Documents

By Martha Gross, Amanda Wachenfeld, Brian Keaney, Jean-Michel Charpentier, Frank Perrone

The Hampton Roads Bridge-Tunnel (HRBT) Expansion widens the existing four-lane bridgetunnel corridor to eight lanes through construction of two parallel tunnels, interstate widening, and bridge expansions. As part of the design-build contract, a supplemental geotechnical investigation was completed to support the design. The investigation for the subaqueous tunnel segment consisted of over 48,400 linear feet of drilling and 7,100 laboratory tests. This paper discusses the challenges of planning and executing a large-scale geotechnical investigation for underground works in a marine environment and the use of big data for effectively managing, interpreting, and transmitting data to the design-builder consistently throughout the investigation.

Jun 23, 2024

By M. D. Lackey

The "Art" of Big Hole Drilling has been in a continual state of evolution at the Nevada Test Site since the start of underground testing in 1961. Emplacement holes for nuclear devices are still being drilled by the rotary drilling process, but almost all the hardware and systems have undergone many changes during the intervening years. The current design of bits, cutters, and other big hole drilling hardware results from contributions of manufacturers and Test Site personnel. The dual string, air lift, reverse circulation system was developed at the Test Site. Necessity was really the Mother of this invention, but this circulation system is worthy of consideration under almost any condition. Drill rigs for Big Hole drilling are usually adaptations of large Oil Well drill rigs with minor modifications required to handle the big bits and drilling assemblies. Steel remains the favorite shaft lining material, but a lot of thought is being given to concrete linings, especially precast concrete.

Jan 1, 1983

"Located on the Big Hole River, three miles from Divide, Montana, and 21.75 miles from Butte.Built in 1899.DAM: Rock-filled wooden crib, 512 ft. long and 57.5 feet high.SPILLWAY: Equipped with flash-boards 189 ft. long, 8 ft. 10 inches high.PENSTOCKS: Two 8 ft. diameter of steel, each branching and supplying two wheels.WHEELS: Four double horizontal, double discharge turbines, made by The James Leffel & Co., 1,000 h-p., 180 r. p. m., direct connected to generators, operating at 60 ft. head. GENERATORS: Four G. E., revolving field, 750 k-w., 180 r. p. m., 800 volt, 3 phase, 60 cycle alternators.EXCITERS: Two water-wheel driven exciters.TRANSFORMERS: 12 250-k-w. G. E. air blast, primary 15,000 volts, Secondary 800 volts.OPERATION: The plant operates essentially as a peak load plant. Except in flood period, there is insufficient water to operate at full load continually. In December its average output is about 500 k-w."

Jan 1, 1913

As the 2009 George Fox Conference neared its conclusion, Arthur Silber, project chief of the Mass Transit Tunnel (MTT) project was able to pull away from the constant buzzing of his Blackberry long enough to give a short presentation and a significant piece of news to the record 318 attendees at the Graduate Center, City University of New York regarding the MTT project. ?As the former administration (The Bush administration) was leaving office, we were told that Congress was notified of the FTA?a (Federal Transit Authority?s) intent to issue final design construction approval to us,? Silber said of recent advancements concerning the $7.2-billion dollar project. It will add passenger rail service from New Jersey to New York City as part of the Access to the Region?s Core project in the form of the Trans Hudson Express Tunnel (THE tunnel). ?That 10-day waiting period ended yesterday (Jan. 26).? In days leading up the Fox Conference, those involved in the tunneling industry, and the MTT in particular, had a lot to be optimistic about. The MTT received environ-mental approval on Jan. 14 (see page 9) and, with the acceptance of the final design, the multi-billion dollar project moved that much closer to a ground-breaking ceremony. So close, in fact, that before leaving his office for the conference, Silber posted the contract documents and plans for the Manhattan Tunnel project online at www.arctunnel.com (an indepth look at the project from Silber is on page 22). While many were interested in the progress of the project, Silber also spoke about the new plans for the cavern complex at the New York Penn Station expansion. The original plans called for two lines that would come into a large cavern complex with a north and south cavern to access the trains. After numerous core samples were taken from the streets of Manhattan, it was deter-mined that this design was not feasible and changes were made that will include a deeper cavern under Sixth Avenue, with 14-m (45-ft) of cover with a 30-m (96-ft) wide cavern that resides entirely under 34th Street. The cavern was also moved 20 m (60 ft) to the west to remain at least 61 m (200 ft) away from New York City Water Tunnel #1. The new design will include three-over-three track arrangement. The mezzanine will be 46 m (150 ft) below street level at 8th Ave, Silber said.

Jan 1, 2009

By Tim O’Neil

If you build a big truck, build a big tire to match it. Let that haulage synergy aid the economics, productivity and lessened maintenance for the unit. Now, Cater-pillar and Michelin have done just that. Discussions began in 1996. Caterpillar was making plans for its 797 ultra-class haul truck. The development team realized the need for a tire that could withstand extreme loads. The 797 would weigh 558 t (615 st) and be capable of 64 km/h (40 mph) speeds. So Caterpillar approached Michelin. The two companies realized the benefits of jointly developing a tire for the 797.

Jan 1, 2002

By Tom Szaraz

Part of a major sewer expansion for the City of Columbus, Ohio. The Big Walnut Outfall Augmentation Sewer?Part II (BWOAS) consists of 13,200 feet of tunnel of 12-foot tunnel passing mainly through glacial deposits with a water head of up to 2 bar. A Lovat RME167SE was used to drive this tunnel with steel fiber reinforced precast segmental liner used for support. This paper will discuss the concepts for tunnel sup-port and TBM selection, the problems encountered with the TBM sealing systems and the solutions used to repair the machine.

By N. E. Norman

During the past few years the underground mining industry and the big hole drilling industry have been involved in a flirtatious courtship, but until recently this courtship did not appear to be taken too seriously by either party. However, many of the promises made by the big hole industry are beginning to come true. Improvements have been made steadily in techniques of mechanical boring of large diameter shafts, raises and tunnels, thus making the big hole industry a more stable partner in the eyes of the mining industry. The mining industry too has made many changes in planning that make mining more attractive to the big hole industry. If there is to be a marriage between big hole drilling and mining, we should certainly take a look at the background of the big hole drilling industry, and examine the three main features of big hole drilling to determine how each applies to mining. Shaft Drilling Since 1950, numerous large diameter shafts have been drilled using rotary drilling techniques. Most of the larger diameter shafts have been drilled for the AEC for underground nuclear testing purposes. However, since 1960 several shafts have also been drilled for various mining companies, particularly in the United States. In 1967, rotary drilling shafts were either completed or in progress at the mining companies listed in Table I.

Jan 6, 1968

By Jorge Madias

Pin holes as a surface defect, and blow holes as an inner defect, occur in billet / bloom / beam blank casting, particularly for Si-Mn killed steel cast with metering nozzle and oil lubrication. If they are present in abundance or have a large size, they may originate defects in the rolled products. Their characteristics, factors behind their formation, as well as usual processing conditions that promote their occurrence are discussed. Finally, the evolution of these defects during reheating and rolling is analyzed, with industrial examples.

Aug 16, 2017

By Darrin Wikoff

"The data, compiled by the Department of Energy (DOE), indicates that the average industrial plant could reduce its total energy cost by 14.8% by implementing effective Life Cycle Asset Management processes. The actual savings varies by industrial classification, but in all cases the potential is substantial and could have a marked impact on the operating profit of the company.Improvements geared towards improving equipment reliability have distinctive linkages to environmental performance, such as reducing the amount of product and raw material waste through routine monitoring of system parameters through predictive technologies, and preventing interruptions to production cycles with a focus on Overall Equipment Effectiveness (OEE).Alcoa successfully reduced solvent disposal costs by more than 40% and GE reduced greenhouse gas emissions by more than 250,000 metric tons. This presentation will show you how companies have successfully reduced energy and disposal costs through a focused effort on manufacturing process reliability.IntroductionSmelter in the ParkThe quaint town of Portland, Victoria protrudes outward towards Antarctica from Australia’s southeastern coastline. Portland is a quiet rural community surrounded by agriculture that draws tourists by the thousands to the southernmost edge of Victoria by way of breathtaking cliff top views of the majestic Southern Ocean, the intrigue of shipwreck coves along the Great Ocean Road, and what most will call the eighth wonder of the modern world, the “Smelter in the Park”. Integrated within Portland’s beautiful landscape is a 356,000 ton/year aluminum smelter that stands as a symbol of collaboration between nature and industry. Nestled atop a ridge which faces “Sail Rock”, a popular destination of local and visiting fisherman, the smelter is engulfed in a mix of brush and wetland preserves that are home to many of Australia’s feathered and fourlegged natives. Also within its interior you’ll find parks and natural landscapes abundant where man and machines coexist with the native inhabitants."

Jan 1, 2009

By E. Kouame, M. D. Everell, D. Hodouin, T. Kasongo

"To properly operate a mineral beneficiation plant it is often necessary to have systematic evaluations of the performances of a piece of machinery, of one of the processes or of the plant as a whole. The state of a process can be described from a collection of data: flow-rate values, particle-size distributions and chemical compositions of the various streams of the circuit studied.However, the obtained raw data are generally redundant and inconsistent from a material balance viewpoint, due to natural disturbances, sampling errors, unreliable instrument readouts and laboratory analysis inaccuracies.BILMAT is a computer program which upgrades mineral processing data, adjusting them in a least-squares sense in order that they may verify material conservation constraints. As a consequence, the program is able to calculate the best values of unmeasured flow rates (such as. circulating load ratios). BILMAT is a very general program in the sense that it can accept various data from any type of mineral processing circuit, and its usefulness is demonstrated here for three processing circuits of a pyrochlore concentration plant: grinding, desliming and flotation.IntroductionComputation of the material balance around any metallurgical process, that is the determination of stream flow rates and composition. is a basic step in its evaluation. In spite of the simplicity of the physical laws of mass conservation. and of the very fundamental need to know the flow of components around a process. it appears, particularly in mineral processing. that material balancing is quite often a difficult task. The reasons for this involve the problems associated with collecting measurements in mineral dressing plants. They are generally poorly instrumented and invariably data must be collected through hand sampling. Due to the heterogeneous nature of the streams, segregation occurs and samples are often not adequately representative, a problem made worse by the lack of circuit sampling facilities, which are often completely ignored by plant designers. Furthermore, the nature of the measurements to be performed (for instance particle size distributions in the fine range) frequently gives inaccurate results."

Jan 1, 1981

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 R. Liu

As Building Information Modeling (BIM) becomes widely adopted by the construction industry, it holds undeveloped possibilities for supporting Facility Management (FM). Some FM information systems on the market claim to address the needs for FM requirement. However, the question of whether the functionalities provided by the current BIM-based FM software companies are those actually required by the FM Professionals still need to be answered. The data is required by FM professionals in the operation and maintenance phases of facilities and type of maintainability problems that frequently occur, which can be solved early in design phase, have not yet been addressed. The aim of this paper is to clarify the frequently occurring maintainability problems and to investigate the potential areas that can use BIM technology to solve the maintenance problems in early the design phase. A survey was conducted to collect perspectives from the industry practitioners for the maintenance problems and their frequency. The survey results indicated that maintainability considerations should be taken into consideration during the facility design phase. The results also address the perceived areas by practitioners that need maintainability consideration in design phase

Aug 1, 2013

By Stefano Colombelli, Nicola Bona, Gabriele Eccher, Luca Schiavinato, Paolo Cucino, Domenico Nave

"BIM technologies provide tools and processes to effectively support the entire life of an infrastructure, from strategic planning to maintenance. As a consequence, infrastructure design processes currently make frequent use of BIM tools. This paper describes the BIM oriented design of the underground railway extension in the metropolitan area of Catania. The paper highlights the design process and the chosen BIM tools considering the boundary conditions characterizing the project, i.e. basic information missing in the final design project, need of coordination between different design disciplines and designer companies, and, finally, need for a flexible design approach able to adapt to changes occurring during design development. INTRODUCTION The underground railway extension in the metropolitan area of Catania is composed of two lots of approximately two km each, namely “Stesicoro-Aeroporto” and “Nesima –Misterbianco”. Works to be realized are: •,Main tunnel: mechanized tunneling using a TBM-EPB machine, for the entire length of the lot; •,Underground stations: San Domenico, Vittorio Emanuele and Palestro, conventionally excavated as enlargement of the TBM tunnel after the partial demolition of precast segments; •,Ventilation and emergency shafts: connecting seven tunnel levels to road level on Stesicoro-Areaposto lot, six on Nesima-Misterbianco lot; •,Additional structures such as technical rooms and parking lot; •,Electric Substation at Monte Po' stop; •,Temporary works: TBM launching and arrival pit to be dismantled at the end of the works."

Jan 1, 2016

By Piotr Pajaczkowski

Hydro generators installed in Itaipu Binacional power plant with 824/737 MVA rated output power (50/60 Hz) belong to the largest ones in the world. Among many unique features the generators are equipped with the largest hydrodynamic thrust bearings ever built (external diameter 5200 mm, axial load equals approximately 3600 t). This paper is an attempt to propose a new thrust bearing design with the use of the state-of-the-art technologies and simulation techniques that demonstrate a reduction of friction power losses generated by the thrust bearing. This paper is divided into two parts. Within the first one the original thrust bearing design which was implemented in the generators is described. Related calculation results based on a thermo-elasto-hydrodynamic (TEHD) calculation software used by Alstom will be presented. A comparison between measurement results gathered in the 1980’s is given. In the second part a potential solution of a more beneficial bearing design is described. The proposed thrust bearing design modification is an implementation of Alstom’s PolypadTM coating. This modern polymer (PEEK) coating material has already been used by Alstom in projects around the world for many years. This coating allows pushing the operating parameters limits toward higher temperatures and lower oil film thicknesses far beyond the limits known for the conventional bearing materials.

Jul 31, 2018

By Jolanta Olkowska-Oetzel

Reactions of gold?phosphino complexes [(AuX)(PR3)] (X= Cl, Br, I; R = organic rest) with Se(SiMe3)2 lead to the formation of gold complexes with chalcogenide bridges. The reaction of the complex Ph3PAuCl and tBuSe(SiMe3) gives the cluster [Au5Se2(PPh3)4]Cl 1. The in situ preparation of the complex [(AuCl)2dpph] (dpph = Ph2P(CH2)6PPh2) by reaction of dpph with Me2SAuCl, and subsequent reaction with Se(SiMe3)2 leads to the formation of [(Au3Se)2(dpph)3]Cl2 2. Reactions of the gold(I) complex [(AuCl)2dpppe], (dpppe = Ph2P(CH2)5PPh2) with Se(SiMe3)2 and InCl3 in different molar ratios lead to the formation of [Au10Se4(dpppe)4]InCl5 3 and [Au4(SeInCl3)2(dpppe)2] 4. The reaction of [(AuCl)2dpph] with Te(SiMe3)2 and GaCl3 produces the isostructural cluster compound [Au4(TeGaCl3)2(dpph)2] 5. From the reaction of Se(SiMe3)2 with [(AuCl)2dppe] (dppe = Ph2P(CH2)2PPh2) and InCl3 [Au8Se4In(dppe)4](InCl4)3 6 can be isolated. The structures of 1 - 6 were determined by X?ray diffraction.

Oct 1, 2003

By K. A. Lewandowski

Agglomeration techniques are widely used by industry to form fine particles into larger masses that are easier to handle and process. One area where agglomeration is potentially useful is in heap leaching operations. With-out agglomeration, fine particles travel through the heap, clogging the spaces between the larger particles and resulting in poor leach solution flow. Poor flow of leach solution will result in long leach rates and/or decreased metal recovery. Agglomeration immobilizes the fine particles and therefore improves heap permeability to fluid flow. Additional additives (binders) are needed to prevent agglomerates from breaking up as leaching solution percolates through the heap. Type II Portland cement and lime are two well-known binders used in gold and silver leaching, but these are limited to alkaline leaching environments. Various other products have been tested as binders, including polymers. This paper summarizes the benefits of agglomeration in heap leaching and the results obtained from the testing of several different agglomeration binders in heap leaching operations.

Jan 1, 2009

By S. K. Kawatra

A high calcium fluid-bed combustor ash has been shown to be an effective binder at dosages of 1 to 2% of the magnetite concentrate weight. Magnetite pellets 1.3 cm (1/2 inch) in diameter were produced with dry crushing strengths greater than 22.3 Newtons/pellet (5.0 pounds force/pellet), which is comparable to the results produced using conventional bentonite binder. The effectiveness of fly-ash-based binders was considerably improved when calcium chloride was added as an accelerator. Addition of calcium chloride at a rate of 0.1 to 0.2% of the total powder weight increased the strength of dried pellets by as much as 22% compared to the strength of pellets made using fly-ash without accelerators.

Jan 1, 1997

By D. D. Banerjee, S. K. Kawatra, T. C. Eisele

A high calcium fluid-bed combustor ash has been shown to be an effective binder at dosages of 1 to 2% of the magnetite concentrate weight. Magnetite pellets 1.3 cm (1/2 inch) in diameter were produced with dry crushing strengths greater than 22.3 Newtons/pellet (5.0 pounds force/pellet), which is comparable to the results produced using conventional bentonite binder. The effectiveness of fly-ash-based binders was considerably improved when calcium chloride was added as an accelerator. Addition of calcium chloride at a rate of 0.1 to 0.2% of the total powder weight increased the strength of dried pellets by as much as 22% compared to the strength of pellets made using fly-ash without accelerators.

Feb 24, 1997

By Vincent Castranova, Jane Y. C. Ma, Joseph K. H. Ma, Chang-geng Mo, Carl J. Malanga

"A group of bisbenzylisoouinoline alkaloids has been shown to exhibit various degrees of effectiveness in preventing silica-induced fibrosis in animal models [1, 2]. The objective the present study was to characterize the binding of several of these alkaloids to phosphatidylcholine vesicles and rat alveolar macrophages using fluorometric and equilibrium dialysis methods, respectively. The lipid binding affinity of these alkaloids was found to depend upon several structural factors including hydrophobic substitutions, chiral configurations, and double oxygen bridge-restricted conformation of the benzylisoquinoline moieties. Tetrandrine, which is a highly effective agent in preventing fibrosis, showed strong binding to both lipid vesicles and alveolar macrophages. In contrast, certain analogues of tetrandrine such as curine and tubocurine, which have little or no effect on silicosis, exhibited only weak binding to lipid vesicles and almost no binding to cells. The moderate binding affinity of fangchinoline to vesicles and cells corresponded to a moderate effectiveness of the compound as an antifibrogenic agent. Methoxyadiantifoline, an alkaloid of unknown antifibrogenic potential, also exhibited high binding affinities for lipid and cells. In conclusion, the results of these studies indicate that alveolar macrophages exhibit large binding capacities for certain members of this class of bisbenzylisoquinoline alkaloids. A positive correlation was observed between binding affinity to alveolar macrophages and the reported antifibrotic potency of these compounds. These data also suggest that the ability of these drugs to interact with alveolar macrophages may be a key step in inhibition of the progression of silica-induced pulmonary disease.INTRODUCTIONInhalation of crystalline silica is associated with the development of silicosis. This fibrotic disease is characterized by the appearance of concentric hyalinized nodular lesions in the lungs with the progressive development of pulmonary dysfunction [3, 4]. Many theories concerning the etiology of silicosis involve silica-induced activation of alveolar macrophages. Evidence indicates that in vitro silica exposures result in the generation of chemiluminescence, and the release of superoxide and hydrogen peroxide from alveolar macrophages [5]. Activation of alveolar macrophages has also been demonstrated after intratracheal instillation or inhalation of silica [5, 6]. Such excess release of reactive products from pulmonary phagocytes has been associated with damage to the lung parenchyma [7, 8]. In addition, silica exposure results in the release of mediators from alveolar macrophages, which enhance proliferation of fibroblasts and collagen synthesis by these pneumocytes [9-12]."

Mar 1, 1992

By E. Dzingayi

Keywords: Pyrometallurgy, furnace, Bindura, nickel The smelter at Bindura Nickel Corporation processes concentrates from its own mines and other external sources. Concentrates are dried, smelted, and converted to a desulphurised matte (leach alloy) for further processing at the refinery. The smelter comprises a drying plant, submerged arc electric furnace, electrostatic precipitator, and three Peirce-Smith type converters capable of treating 150 000 tonnes of concentrates per year. Concentrates are dried in a rotary coal-fired kiln, blended with fluxes, and smelted in a six-in-line submerged-arc 15MW electric furnace. Slag is tapped and granulated for disposal, and matte is tapped at regular intervals for blowing in Peirce-Smith converters. The paper details the 37-year history of the smelter, including furnace rebuilds and operating parameters as they have evolved in response to changing feed compositions. Special challenges, particularly relating to the treatment of high talc concentrates, are also described.

Jan 1, 2006