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The mining industry continues to experience a skills shortage and this is having an impact on the ability of mining companies to operate sustainably. Apart from a few exceptions, there is a dearth of geologists, mining engineers, metallurgists as well as environmental scientists and other professionals in the global mining industry. This relates to both quantity and quality. It makes good business sense for mining companies to employ local professionals rather than expensive expatriate staff. In some cases a mining company could employ more than 10 local mining engineers for the cost of one expatriate. However, in many countries local professionals are not always equipped professionally to work on mine sites. The result is that many companies are not operated optimally due to human resources gaps. In some cases, particularly in key areas such as mine planning, this threatens the sustainability of the operation or at the very least results in sub-optimal resource utilisation. This paper briefly presents some of the issues and strategies being implemented and that might be implemented to maintain a sustainable supply of quality minerals graduates to the industry in 2011 and beyond.

Jan 1, 2011

By G. Norman Owen, Roger E. Scholl

INTRODUCTION The analysis and design of underground structures to resist vibratory motion due to earthquakes has been of interest to engineers for several decades. The dynamic stability of a powerhouse cavern was considered in the 1960s (Campbell and Dodd, 1967). About the same time, the designers of the San Francisco Bay Area Rapid Transit system developed procedures for analyzing the subaqueous tunnels placed under San Francisco Bay and the tunnels excavated along the land portions of the alignment (Kuesel, 1969). Japanese designers developed fairly sophisticated procedures for analyzing subaqueous tunnels during the late 1960s and early 1970s (Kuribayashi et al., 1974). In the past decade, proposals to site important critical underground facilities in regions with moderate to high seismic activity have increased the interest in earthquake engineering of underground structures. Seismic designs or seismic studies have been conducted for rock caverns for storage of petroleum or location of power plants (Yamahara et al., 1977; Glass, 1976), buried tanks for fuels or rad¬ioactive waste (Fukushima et al., 1977; URS/Blume, 1976), tunnels for disposal of nuclear waste (Yanev and Owen, 1978; Wahi et al., 1980), and urban mass transit tunnels (Monsees and Merrit, 1984). One of the greatest drivers of the interest in seismic analysis and design of underground structures has been the proposals to dispose of high-level nuclear waste in mined repositories some 300 to 600 m (approximately 1,000 to 2,000 ft) below the ground surface. In 1979, the authors, in conjunction with Professor Tor Brekke, presented a paper on an evaluation and design procedure used in a study of a proposed nuclear waste repository (Owen, Scholl, and Brekke, 1979).

Jan 1, 1985

By Steven W. Hunt

Appropriate seals, portal ground improvement, and compatible shaft construction techniques are vital elements for launching and receiving tunnels effectively in urban areas where adjacent property requires protection from excess ground movements. This paper focuses on seals and ground improvement along with shaft wall types, required to launch or receive tunnel boring machines within wet, permeable ground at the portal zone. The paper also discusses probing to verify suitability before the tunnel eye is cut. Methods addressed include: rubber gasket seals; soft eyes; double walls; top hats for reception; and, portal zone ground improvement (permeation grouting, jet grouting, un-reinforced slurry diaphragm wall panels, ground freezing, deep soil mixing, dewatering, and over-excavation and backfilling). This paper focuses on challenges with launch and reception of pressurized-face TBMs with precast concrete segment linings. Challenges related to pipe jacking are discussed in a separate paper titled ?Mitigating Microtunnel Launch and Reception Challenges? (Hunt and Finney 2008).

Jan 1, 2008

The two candidates in the upcoming presidential election in the United States each say that they have their own solution to the nation?s energy problems - solutions that will increase the amount of energy available, lessen the nation?s dependence on foreign sources and reduce the amount of pollution released to the atmosphere. Democratic nominee Sen. Barack Obama and Republican candidate Sen. John McCain both advocate research funding for coal-to-liquids and clean coal technologies. McCain also supports increased oil and gas drilling offshore. And Obama has even made some noises in that direction, although his plan leans heavily on the increased use of renewable energy sources. The energy debate is not new to this election. Congress and whichever party is in the White House has for years been trying to craft a comprehensive energy policy. One difference in this latest debate is that the increased use of nuclear energy has gained more attention. Current President George W. Bush has said he favors the increased use of nuclear power as part of the nation?s energy package. And McCain said he supports the building of more nuclear power plants. Obama has not said much about that. The American public is also showing signs of changing its stance on nuclear energy. To be sure, images of Three Mile Island and Chernobyl are still alive in some minds. However, the American public has said it wants cheaper energy and they want it produced more cleanly. With nuclear, the nation can have both. In the United States, nuclear accounts for slightly less than 20 percent of the electrical power used (see interview with Gary Steele of Energy Fuels on page 27). Globally, that figure is about 15 percent. And there are several nations that derive better than half of their power from nuclear sources. Add to that the world?s increasing need for more energy and the future of nuclear is bright.

Jan 1, 2008

By M. Mikhaylenko

The most common methods of processing of uranium ores is sulfuric or carbonate leaching with conversion of hexavalent uranium to uranyl carbonate or sulfate anionic complexes followed by sorption of the later by strong base anion (SBA) exchange resins. It is known that chloride anion has high affinity for SBA resins so that it depresses sorption of anionic complexes of uranyl. Application of the SBA resins becomes impractical for recovery of uranium when chloride concentration in pregnant leach solution exceeds 3-5 g/l [1-3].

Jan 1, 2012

By Frank P. Frandina

The Heartland Corridor Clearance Improvement Project is part of a regional Public-Private initiative to allow double stack container trains a direct route from the Port of Norfolk through Virginia, West Virginia, Eastern Kentucky and into Central Ohio. The project involves clearance improvements to twenty-eight tunnels, twenty-one of which require structural modification. With construction of the first Package of tunnels just underway at press time, this paper summarizes the program implementation from design through the initial stages of construction.

Jan 1, 2008

Things are going well in the mining and construction industries world-wide. So good are things that from April 23 to 29 more than 500,000 visitors involved in those two industries attended the bauma 2007 Trade Show in Munich, Germany. Bauma is an international trade fair for construction and mining equipment that took place at the New Munich Trade Fair Center. It is hosted by Munich once every three years. This year was the most successful bauma ever and further strengthened the shows position as the world leader in the field.

Jan 1, 2007

By Paul A. Roy

The North Shore Connector Project for the Port Authority of Allegheny County constructs twin Tunnel Boring Machine (TBM) tunnels through cohesive soils and rock beneath the Allegheny River and a narrow city street in Pittsburgh, PA. The tunnel alignment includes an historic building on shallow foundations, modern buildings on deep foundations, and an office building constructed directly over the alignment during the design of the tunnel sections. This paper provides an overview and update of the general site conditions, TBM tunnel design, and support of excavation for the TBM launching pit. Deformation limits, ground improvement, monitoring and mitigation plans are also discussed.

Jan 1, 2008

By Steve Karl

Introduction Technological advances in mining and processing have started the domestic mining and mineral industry back on the road to competitiveness. A massive trade deficit, however, coupled with foreign competition and more government regulations threaten to slow this recovery. So say mining executives in Colorado and Minnesota. These industry decision-makers agree that their challenge is to continue the technical innovations of their industry. The journey back to profitability and competitiveness means improved products, they say, but at lower production costs. At separate gatherings in January, officials in both states said that they believe their industry is up to the challenge. Worker attitudes will have to change, they understand, and management styles will need adjusting. And, while they are willing to make the necessary adjustments, they are going to need some help. Or, at the very least, less interference from the federal government. Foreign markets, all but closed to American products, must be opened up on a reciprocal basis. The nation's $170 billion trade deficit is a priority item that can no longer be ignored. And, closer to home, federal and state environmental regulations concerning mineral production must themselves be monitored. 1987 in Colorado While Colorado's service and trade industries should have a fairly good 1987, the state's mining industry can expect another disappointing year filled with layoffs and declining profits, according to the Colorado Mining Association. Once again, foreign competition and government regulations are seen as the main reasons for the mineral industry's woes. And state mining officials see little relief until at least the 1990s. Speaking to a group of reporters at its annual press briefing in Denver, CMA officials said Colorado's overall nonfuel mineral production is expected to fluctuate between a flat and declining growth trend. Mining employment in the state is expected to fall by 400 people this year, to about 7500. In 1981, Colorado mines employed as many as 17,800 people. During the 1970s and early 1980s, the employment rate in mining in the state grew by 12% annually, according to a summary report compiled by the CMA. Last year, worldwide molybdenum production continued to exceed demand US moly producers, therefore, were forced to continue their familiar path of production cutbacks, as well as workforce reductions. And some molybdenum mines in the US closed altogether, the CMA report stated. In Colorado, Amax's Climax and Henderson molybdenum mines operated at about 50% of combined capacity. Climax employed about 200 people at the beginning of 1987, producing about 5.4 kt/d (6000 stpd) or ore. Henderson employed about 700 people, producing about 24.5 kt/d (27,000 stpd) of ore. In coal, the number of licensed coal mines in Colorado has declined from 124 in 1960 to 43 in 1986, of which only 23 were producing. Once a stable source of employment and production, the metallurgical coal industry in the state has only one surviving metallurgical coal mine, Mid-Continent's Orchard Valley mine. High production and transportation costs, weakness in the US steel industry, and a weak market position have contributed to the decline, the summary reported. "The challenge facing most mining companies in the United States today is to survive," said

Jan 3, 1987

By S. Johnson

Introduction The mining of aggregates underground has grown steadily over the last 25 years. Growth has come in both production volume and in the importance this segment of the industry is playing in the continuing supply of construction aggregate. Underground aggregate mines will continue to grow in both number of operations and complexity, as the replacement of zoned reserves in metropolitan areas becomes crucial. This growth will result in a shortage of qualified mine managers, possibly limiting the success of these facilities. The aggregate industry will have to modify current practices in order to meet the growing demand for this specialized skill. Segment Growth Underground mining for aggregates is not a new idea. Martin Marietta has been operating underground mines since 1969, and currently operates 16 underground mines ranging in size from 250,000 tpy to 2,500,000 tpy. These mines represent less than 4% of the total number of operating locations, but contributed 9% of the annual production in 2004. Though they range in size and production capacity, the importance is evident. The 2000 United States Census revealed several trends that are of interest to the aggregate mining industry. For the period 1990-2000 the U.S. population grew by 33 million or 13%. There were nine major metropolitan areas with a population of five million or more. These nine areas accounted for 30% of the total U.S. population. More significant was the fact that the population growth in these nine metro areas was 25% of the growth for the entire country. These statistics tell us that the population is expanding in these major metropolitan areas at a staggering rate. The same thing is happening to some degree in every population center. Population growth increases the demand for local aggregate while reducing the available area to mine that aggregate. The need for an economical supply of aggregate to support community expansion is a problem that will grow as older quarries are mined out and closed. This will be an issue that communities of all sizes will have to deal with. A reliable and cost effective supply of quality aggregate is crucial to support community expansion.

Jan 1, 2006

By I. Nimmo

Since the beginning of Aluminum mining and refining the industry has lived with distributed control rooms and suffered from many behavioral problems common with this design. When Human Factor/Ergonomic design is introduced to a Western Australian installation a common centralized control room realized many improvements including economic payback. Communications issues were resolved, better coordination of materials, improved situation awareness during startups, abnormal operations and an opportunity to make improvements during normal operations characterize the changes at the Worsley Refinery. This presentation will review the reasons for the change. Since the beginning of Aluminum mining and refining the industry has lived with distributed control rooms and suffered from many behavioral problems common with this design. When Human Factor/Ergonomic design is introduced to a Western Australian installation a common centralized control room realized many improvements including economic payback. This presentation will review the reasons for the change, what changed and the process of changing the culture from reactive to predictive and what difference that has made.

Jan 1, 2011

By A. Martikainen

Field tests concerning a fog mesh method for fog removal are discussed. The first tests were performed at the Pyhäsalmi Mine, Finland. As this study gave promising results, further studies were completed at the Orivesi Mine. The results of these most recent field tests are presented and the two studies are compared. The Orivesi test set consisted of four materials. These included air filter fabric, fibrous filter fabric, a plastic greenhouse mesh, and an aluminium mosquito net. The variation of the Orivesi results was more noticeable than what was found previously. The best fog removal effect of all tests was achieved with the aluminium mosquito net, while the plastic green-house mesh performed worst. The humidity reduction by aluminium net was more profound than any of its precedents. More mesh materials will be tested in the near future.

Jan 1, 2007

By Daniel H. Isreal

Because the federal government owns and controls nearly 80% of the most valuable oil shale reserves in the West, it is inevitable that federal leasing and siting will play a prominent role in development of an oil shale industry during the 1980s. Also, because of recent enactment of the Synthetic Fuels Corp. authorizing up to $88 billion in loan and price guarantees-federal financing will provide the critical incentive to permit private investment in a still infant industry.

Jan 1, 1981

By S. Holtermann

Through the process of Riverbank Filtration (RBF), the Louisville Water Company plans to obtain a higher quality source of water for their B.E. Payne Water Treatment Plant (WTP) by means of four collector wells located in the alluvial aquifer along the bank of the Ohio River. The collector wells are connected to a 2,850 L/s (65 mgd) pumping station by a 2,362 m (7,750 ft) long, 3 m (10 ft) finished diameter tunnel located in limestone and shale bedrock, which is approximately 45 m (150 ft) below the surface. High tunnel boring machine (TBM) production rates were achieved in this moderately weak bedrock; most of the tunnel only required support in the crown. An unanticipated water-bearing fault and unanticipated ground behavior proved challenging and required quick thinking to minimize impacts to construction. Tunneling conditions are discussed in detail, together with the methods used for overcoming the groundwater and ground behavior challenges. The tunnel is expected to be completed in April 2009.

By R. D. Sharpe

Gypsum wallboard manufacturers in the United States shipped 3.18 billion m2 (34.2 billion sq ft) of wall-board products during 2004 versus 2.93 billion m2 (31.5billion sq ft) in 2003. Following a historic high production of gypsum wallboard products in 1999, production decreased in 2000. But it has steadily increased during2001 through 2004. Wallboard production in the United States increased about 8.6 percent in 2004 from 2003. Following several years of a “building boom” of new wallboard plants and the expansion of the manufacturing capacity of several existing plants, 2004 was a relatively quiet year. However, several new plants and capacity expansions were announced or are in progress during 2004.

Jan 1, 2005

By Charles C. Dahl, Gordon C. Presley, Andrew E. Nevin, Bruce A. Kennedy

How does SME-AIME cope with profound changes in technology, markets - and most importantly - in employment patterns facing its membership today? This is the question that prompted the Society's Board of Directors to appoint a Long-Range Planning Commission (LRPC) (see ME, Feb. 1984, pp. 118 and 128). This is also the question addressed most particularly by the LRPC's Scope Committee. The Committee started its deliberations by asking such basic questions as "Who are we?" and "What is our business?" The Scope Committee then reviewed the findings and recommendations of other more specialized committees to develop and integrate their concepts of the Society's business for the next 10 years. The policy-making suggestions of the LRPC were reviewed and acted upon by the Board of Directors at its open meeting in Los Angeles on Feb. 26, 1984. At the Oct. 23-26, 1984 SME Fall Meeting in Denver, the Board will again review LRPC recommendations. In answer to the question "Who are we?" the Scope Committee proposed description, which was accepted by vote of the board of directors: . . A technical and professional organization that consists of individual members, namely those mining engineers, metallurgists, geologists, earth scientists, economists, managers, educators, and other professionals concerned with all facets of exploration, production, distribution, and using of mineral commodities. "These mineral commodities include all metals; industrial minerals, including construction materials and fertilizers; coal, oil shales, tar sands, and other mined fuels. Among the earth's mineral resources, only wellpumped oil and gas lie outside the Society's specific purview. "Traditionally, SME members work in the fields of engineering, technology, exploration and discovery, development, construction, mining, quarrying, beneficiation and processing, handling and transport, equipment manufacturing, sales and marketing, data processing, safety, land reclamation, environmental protection, taxation, administration, and management of these elements. "Members practice their professions in industry, in universities and research institutions, and in government. They may be operators, manufacturers, sales persons, contractors, consultants, analysts, researchers, educators, advisors, regulators, or members of supporting staffs. "The members of the Society are leaders in dedication to their crafts, in innovation, and in the pursuit of excellence. Among their numbers they count the most distinguished of engineers, applied scientists, and managers. "The Society is based in the United States, is active on a worldwide basis, and is open to nationals of any country. Certain qualifications must be met for attaining and maintaining membership." Purpose of the Society As to the question "What is our business?" the Scope Committee restated our purpose in light of current practice and the constitution of AIME and the bylaws of AIME and SME. The Board of Directors accepted the following proposed purpose of SME: "To further the professional development and well-being of its members by publishing and distributing technical writings, news, and information; by sponsoring meetings of members; by providing forums for discussions and for continuing education; and by fostering communication on the subjects within its purview. "The Society assists educa-

Jan 4, 1984

The Sandvik DE710 diamond core drill has become one of the most popular exploration drills available. It is operated on exploration and mining projects in locations around the world. The compact nature of the DE710 allows a small footprint on site. This has proven to be a great benefit in difficult access areas where site preparation can be limited. The DE710 drill is available in a range of con-figurations to suit global operational and environ-mental demands. It can be truck-mounted for greater maneuverability and ease of relocating the drill between sites. The drill can also be fitted to crawler tracks, powered from the rig hydraulic system, making it a small, self-propelled unit for areas with difficult site access. And the DE710 is available in a shack-mounted configuration for cold weather applications, ensuring a protected working environment for the drill crew. The DE710 is powered by a 6.7-liter engine that produces 141 kW (190 hp) at 2,200 rpm to power the rig hydraulic system. The engine complies with the Tier 3 emissions standards that are being introduced in many countries. The hydraulic system design for the Sandvik DE710 is based on the company?s philosophy of selecting the best available products to suit the application. The main hydraulic pumps and motors are the variable displacement design. This allows for greater fl exibility and precise control of critical drilling functions. The cooling system has also been designed for operation in ambient temperatures up to 50° C (122° F) to cope with varying global operational demands.

Jan 1, 2009

By Samer Sadek, Brian Hagan

We are thrilled to welcome you to the 2025 Rapid Excavation and Tunneling Conference (RETC), which will be held in Dallas, TX. This year’s conference will showcase the continued trend of strong industry interest, as there will be a record setting 115 papers being presented over the course of three days. The set of papers compiled in this book captures the latest and greatest information on a broad array of topics within our fascinating tunneling industry. We hope that the compilation of selected papers in this book will provide a comprehensive recap of the conference while also providing a source of future reference for contractors, engineers, and anyone in general who is a student of our beloved and unique industry. Since its inception in 1972, RETC has been the preeminent tunneling forum to promote ideas, tell stories, share lessons learned, and promote new technologies. RETC prides itself on its focus towards highlighting real-world experiences and practical ideas, with the intent to help the entire industry learn from one another and grow. The need for us all to stay sharp and remain on the cutting edge of technology has never been stronger – the technology and ideas that have been applied in aerospace are now attempting to mix with tunneling, and the advancement of AI continues to permeate all industries. However, no amount of technology or AI can fully replace the human element, and in our tunneling industry, the human element is key and is what sets us apart. In tunneling, every project is different, because the ground is always different. We can only take what the ground will give us, and we must rely on our past experiences to get through present day challenges. Most importantly, we must rely on each other. This is the heart of what RETC is all about. For those of you attending this conference, we encourage you to attend as many sessions as possible and engage with your colleagues to discuss during the breaks in between sessions. This sharing of ideas is what keeps us connected and helps to expand our industry. Please also try to engage with the scholarship students and the newcomers who will be in attendance, as it is the new ideas and fresh energy from the next generation that will continue to make our industry thrive into the future. The program chairs thank and greatly appreciate the efforts made by our session chairs, co-chairs, authors, the members of the RETC Executive Committee, and most importantly the SME staff towards making this RETC possible.

Oct 1, 2025

By J. -G. Swanson

Dust control in longwall coal mining depends primarily on the prevention of dust at the source and secondarily on the suppression of airborne dust. One of the primary methods for the prevention of dust is the wetting of the coal face prior to extraction, which can be achieved with water spray systems installed on the shield supports. The spray droplets must travel across the airway to the longwall face, where high ventilation air speeds can entrain water droplets and prevent them from reaching the face thus minimizing the dust control at the source. Through an evaluation of spray plume characteristics in a wind tunnel, the droplet size and droplet drift behavior was determined. This drift behavior was examined by evaluating the spray plume concentration drop and the droplet size shift near the nozzle exit at varying air speeds. Based on these evaluations, CFD modeling was applied to simulate the spray behavior for varying geometries. These results led to the selection of appropriate spray nozzles capable of carrying water droplets to the face at higher air speeds, resulting in an adequate wetting of the coal face and reduced dust generation.

Jan 1, 2012

By John Rudolf

Metropolitan Washington Airport Authority is currently undertaking the first Phase of Metro?s Extension to Northern Virginia. A wide range of tunnel options was considered for the Tysons Corner segment that involves about 20,000 feet of track and four stations. After consideration of many options that involved EPBM single track tunnels, NATM tunnels and large bore tunnel concepts for the entire Tysons alignment, the design now being progressed into construction involves two 520 meter (1,700 feet) long soft ground NATM tunnels with several hundred feet of cut-and-cover construction. The paper discusses the process that led to selection of the short NATM tunnels as the most feasible of the options considered for Tysons.

Jan 1, 2008