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By Tony Peglas, Harry Asche, Eva Wood

The North-South Bypass Tunnel is a new $AUD1.5 billion underground traffic route in Queensland, Australia, a project of the Brisbane City Council. The tunnel is approximately 5.2 km long, bypassing the Central Business District, and is adjacent to and below major buildings and services. Road tunnel alignment issues include the complex southern connections to the Pacific Motorway and the design of ramps to the east and the north. A review of road tunnel alignment criteria and accident data for Australian and overseas tunnels, similar to the proposed NSBT, are discussed. The key findings of this review lead to a rationalization of the traditional tunnel cross sectional width allocation. The road alignment design elements adopted for the NSBT are also discussed. The NSBT route crosses beneath the Brisbane River. Geotechnical investigations and hydrogeological modelling are described. The crossing has a fundamental impact on the alignment and the tunnelling methods. The tunnelling methods to be adopted and the tunnel support are described. The geotechnical investigations and hydrogeology analysis culminate in the selection of a single shielded TBM for the reference design. These outcomes are related to complex issues of hydrogeology and contaminated groundwater. These are discussed in detail.

Jan 1, 2005

By K. Norrena

Grade control in open pit mining requires the specification of dig limits that account for mineral grades, economic costs, and selectivity of mining equipment. Visual identification of ore rock types is ideal, but this is not always possible in lower grade disseminated deposits where ore/waste contacts are not visually discernible. In this case, conventional grade control practice consists of a two-step procedure (1) create a map of mineral grades at some selective mining unit scale, and (2) determine practical ore-waste boundaries or dig limits on the basis of the gridded block grades or assay information. This procedure is laborious, depends on a subjective assessment of where the boundary should be, and may be economically sub-optimal. We pose the determination of dig limits as an optimization problem and solve that problem with the technique of simulated annealing. Simulated annealing has the unique advantage of being able to combine multiple non-linear constraints into a single objective function. We use maximum profitability and the ability of the equipment to mine the proposed dig limits as constraints in the determination of optimal dig limits. We require a map of expected profit for eah block. Geostatistical techniques are recommended, for mapping expected profit but not necessary. Geostatistics will provide a quantification of the uncertainty in the grades within rock types using all available blasthole samples and exploration drilling. Some variant of L-optimal estimation or kriging can be used to determine the block-by-block classification that is economically optimum. We also need the expected profit for each block. It is unrealistic to assume free selection, that is, each block cannot be extracted independently of its neighbors. The optimal balance of ''accepting dilution'' and ''wasting ore'' is achieved to maximize profit subject to equipment constraints.

Jan 1, 2001

Accurately estimating load distributions and ground responses around underground openings play a significant role in the safety of the operations in underground mines. Adequately designing pillars and other support measures relies highly on the accurate assessment of the loads that will be carried by them, as well as the load-bearing capacities of the supports. There are various methods that can be used to approximate mining-induced loads in stratified rock masses to be used in pillar design. The empirical methods are based on equations derived from large databases of various case studies. They are implemented in government-approved design tools and are widely used. There are also analytical and numerical techniques used for more detailed analysis of the induced loads. In this study, two different longwall mines with different panel width-to-depth ratios are analyzed using different methods. The empirical method used in the analysis is the square decay stress function that uses the abutment angle concept, implemented in pillar design software developed by the National Institute for Occupational Safety and Health (NIOSH). The first numerical method used in the analysis is a displacement-discontinuity (DD) variation of the boundaryelement method, LaModel, which utilizes the laminated overburden model (Heasley, 1998).

Jan 7, 2020

By Stanley M. Miller

Analysis of discontinuous rock masses for engineering design purposes requires information about fracture characteristics. For such studies, fractures or other elements of the rock fabric (bedding, foliation, etc.) should be considered in a statistical manner because they generally have high frequencies of occurrence and are discontinuous over the design area. A practical design procedure includes defining structural domains as those areas which contain fractures with similar orientation patterns. Within a structural domain, the statistical distributions of fracture set characteristics (spacing, fracture density, dip, dip direction, etc.) may be computed from mapped data and then used to quantitatively describe the rock fabric. These distributions can then be randomly sampled (using Monte Carlo techniques) to simulate the rock fabric and to help define potential failure surfaces along fractures. 1 The prediction of failure geometries is an essential part of stability analyses used in designing rock slopes or underground openings. In current probabilistic design procedures, Monte Carlo techniques that rely upon the iterative generation and analysis of deterministic instability models do not incorporate spatial aspects of the random variation in fracture set characteristics, 1,2 but consider the characteristics to be spatially independent.

Jan 1, 1979

By Rajive Ganguli

There are several elements of online pedagogy and information technology that are being used in the University of Alaska Fairbanks’(UAF) course “ES 201: Computer Techniques,” to enhance classroom teaching. The use of information technology in this class grew from a desire to make lecture notes available to students. This has grown to include a sophisticated, online delivery software package. It provides chat rooms, discussion groups, and online testing and grading. Online delivery aside, the class uses the telnet, e-mail and C++/FOR-TRAN compiler facilities of the university server during class to enhance learning. During class, for example, the students read the lecture notes on the Web browser, telnet to their university Unix accounts, check their e-mail and download programs (to be covered in class) sent by me, and then compile, run and modify the programs. The class, therefore, requires students to be active most of the time. This ensures their full attention and better learning due to the hands-on experience (Fig. 1).

Jan 1, 2000

By E. A. Metz

Perfect combustion in an engine would produce only water vapor, carbon dioxide and nitrogen as by-products; however, complete combustion is never achieved. As a mobile power plant, the diesel engine is relatively inefficient in terms of energy produced from the energy potential of the fuel. The diesel is not a perfect engine. The fuel burned can undergo a very large number of reactions in the combustion chamber. It only stands to reason that a large number of compounds are contained in the exhaust, actually, thousands of chemicals. The exhaust can be broadly divided into a gaseous phase and a particulate phase. Each phase is made up of organic and inorganic compounds. The vapor phase contains carbon monoxide, sulfur dioxide, various oxides of nitrogen and many hydrocarbons. The particulate phase contains clusters of respirable inorganic particles made mostly of carbon. This paper will address the health hazards, as we know them today, of the major components of the particulate phase in the exhaust of diesel engines. It will briefly examine the operational factors of the diesel engine as it applies to particulate emissions. Longitudinal studies of occupationally exposed miners are needed with documentation of levels of exposure before a chronic effect of exposure can be determined. At this time, it is not possible to conclude from human studies the level of diesel exhaust exposure that results in the observed lung cancer risk.

Jan 1, 2001

By F. H. Muge

This paper intends to present a general methodology implemented in a software package and which can be applied, whatever the exploitation methods, mining constraints and time basis, to mine planning and production schedulling. Examples are: presented covering the medium-term and short-term planning procedure and the production schedulling for two underground mines located in the South of Portugal (Neves- -Corvo and Aljustrel Mines). Both are complex suiphide orebodies with differ- ent exploitation methods (Neves-Corvo: cut-and-fill; Aljustrel: Long-hole stop- ping).

Jan 1, 1992

By Aurel Goodwin, Diann Kraft, V. S. Znamensky

This chapter deals with the Mine Safety and Health Administrations's (MSHA] concern and obligations with regard to asbestiform minerals. Asbestiform minerals are defined as the magical group of hydrated, silicate minerals that possess a fiberlike structure capable of being woven into cloth. Their unique combination of properties, such as resistance to heat and chemical attack, high tensile strength, and flexibility was recognized centuries before Christ. Pausanias, the early Greek geographer, speaks of golden lamps, made about 430 BC, with in- combustible wicks of Carpathian flax. The Ro- mans used asbestos as cremation clothes to con- serve the ashes of deceased persons of rank. Charlemagne had an asbestos table cloth that he used to pass through fire to clean (Lanza, 19381. Early recognition of the health hazards associated with exposure to asbestos was documented in the first century by Pliny the Elder, a Roman naturalist, and Strabo, a Greek geographer. Both wrote of slaves with sickness of the lungs, whose occupation was that of weaving asbestos into cloth. This concern for the health of asbestos workers disappeared over the ages. Today, with the use of modern technology, asbestos products have been greatly exploited. The asbestos output has increased over a hundredfold in the past 70 years. World production has jumped from 454 t/y (500 stpy) in 1900 to 4.5 Mt/y (5 million stpy) in 1978. An increase in health problems for asbestos workers accompanied this increased usage. However, it was not until the modern era that the association of asbestos with chronic respiratory disease was rediscovered. Reports were published at the turn of the century documenting the effects of asbestos exposure on textile workers. One such report in 1907 by H.M. Montague Murray described the post mortem findings on a 34-year- old carding machine operator. Murray de- scribed the lungs as showing extensive diffuse pulmonary fibrosis spicules of asbestos. Subsequently, more reports of pulmonary fibrosis following inhalation of asbestos were published, including an epidemiological study of asbestos miners in 1930 (Merewether and Price, 1930), at Thetford, Que., Canada. This study took place at the mine 52 years after large-scale mining of asbestos had begun. But, the cancer- producing potential of asbestos was not established until 1949 when a report by Merewether in England described an excess of cancer of the lung and pleura [the lining of the lungs) among individuals dying from asbestosis (Merewether, 1949). In the past decade much attention has been focused on asbestosis, mesothelioma, and bronchogenic carcinoma, as the three major biological effects associated with asbestos ex- posure. Parenchymal and pleural asbestosis is a fibrosis in the substance of the lung with thickening and often calcification of the membranes lining the thoracic cavity. Mesothelioma is a malignant tumor of the membranes lining the thoracic or abdominal cavities, and bronchogenic carcinoma is a cancer of the lung tissue itself. These diseases occur in various degrees and combinations. The severity and occurrence of these biological effects are directly influenced by conditions such as dose response relationships, intensity of exposure, duration of exposure, lapse of time since initial exposure, and cigarette smoking. Numerous studies indicate that the relationship between these conditions and the incidence of disease is proportional. Congress has recently concluded (Congressional Record, 1979) that, "exposure to asbestos fibers has been identified as significantly in- creasing the incidence of cancer and other severe or fatal diseases such as abestosis." Congress conveys its concerns for the safety and health of the nation's miners through the Federal Mine Safety and Health Act of 1977 in which it gave MSHA the authority to set safe

Jan 1, 1986

By Otis M. Clarke

The Eufaula bauxite-kaolin district in southeastern Alabama is an important source of raw material for the refractory industries in the United States. At the present time, five companies are mining and processing bauxite and kaolin from this district and a sixth company is holding substantial reserves. Mining operations are expanding, but finding new ore reserves is a major problem. The Geological Survey of Alabama sponsored geologic research in the Eufaula district to: 1) investigate the utilization of sandy kaolinS and other clays associated with bauxite-kaolin deposits; 2) find limits of the bauxite district, looking for possible extensions; and 3) study the geology of the district, looking for patterns or trends that may aid in finding new ore reserves. This work was done with the full cooperation of mining companies operating in the district and property owners. Research was aided by the U.S. Bureau of Mines and the University of Alabama. The investigation included detailed geologic mapping of mines, drilling in selected areas, and making mineral analyses of bauxite and clays. The mapping was performed primarily by pace and compass because of the complexity of the deposits studied, but aerial photographs were used to a limited extent. Drilling included both auger and core drilling. The auger drilling was limited to 100 feet, but core holes were drilled as deep as 200 feet. The term 'bauxite,' as used here, indicates a mixture of minerals containing more than 50 percent gibbsite. Bauxitic clay is a mixture of gibbsite and kaolinite that contains more kaolinite than gibbsite. The term "kaolin" indicates a clay composed of predominantly kaolinite. Other clays in the Eufaula district are composed of kaolinite, illite, quartz, mica, and goethite or hematite.

Jan 1, 1971

By S. Mathur

Future Florida phosphate reserves contain higher MgO than presently mined deposits. The high MgO content is contributed by dolomite and Mg-rich clay, palygorskite. Selective flocculation was attempted to reduce the MgO content of apatite in synthetic mixtures of apatite with dolomite and palygorskie. Mixed mineral selectivity was predicted in the apatite-dolomite and apatite- palygorskite systems with Poly(ethy1ene oxide) (PEO) flocculant. Loss of selectivity in the mixed mineral systems was primarily attributed to heteroflocculation, which was minimized by addition of a Site Blocking Agent (SBA), a lower molecular weight fraction of PEO, prior to addition of the flocculant. A 80:20 mixture of apatite-dolomite (or palygorskite) was upgraded as 95% apatite at more than 80% recovery level in the product fraction.

Jan 1, 1995

By Gene R. Block

The most economical method of reclaiming land that has been mined, whether it be in urban areas or in rural areas, is when the final configuration of the mining area is that which is required by the subsequent use. Surprisingly, there are a number of examples of this situation. In the arid southwest where water production for the expanding population is a problem, many urban sand & gravel excavation areas subsequently serve as holding basins for ground water recharge. In other areas of the county where water is not in short supply, sand and gravel excavations can be planned in such a way that subsequent land uses such as parks and homesites can be enhanced by utilizing the excavated areas as a water amenity. Reclaiming land for agriculture is another example of utilizing the excavated area for a subsequent use providing the excavated area has not been mined too deep. Other than replacing the layer of topsoil on the excavated area, the final configuration of the mining area is in many cases ready for the subsequent agricultural use.

Jan 1, 1984

By Arthur S. Radtke

The structural setting of disseminated-replacement gold deposits of the Carlin-type and other aspects of their genesis are closely related to events which took place during the evolution of the Basin and Range province. The deposits formed as a result. of chemical and physical processes which took place at shallow depths in the roots of hot spring systems at moderate temperatures (about 200°C) and low pressures (about 25 bars) (Radtke and Dickson, 1974). Locations of Carlin-type gold deposits in the Basin and Range province are shown in Figure 1. Most of the block-faulted mountain ranges in the Great Basin formed by tectonic activity that happened since Miocene time, although faulting in some places probably began in Eocene to Oligocene time (Hamilton and Myers, 1966). The Carlin-type deposits are spatially related to Basin and Range-type faults: Many deposits, such as Getchell, Pinson, Preble, and Cortez, occur along the flanks of ranges, while other deposits, including Carlin (Radtke, 1974) occur within the ranges in areas characterized by crosscutting and intersecting high-angle or Basin and Range-type faults. The association of the ore deposits with Basin and Range-type faults is evidence that ore deposition is young, Miocene or later. The steep, high-angle faults played three roles: first, they provided deep channels for upward-flowing solutions; second, in preparing the rocks for fluid penetration by brecciation and general rock dislocation; and third, they moved sedimentary carbonate rocks, favorable for ore deposition, from deep levels to near-surface positions where the physico-chemical conditions were more suitable for the deposition of ore.

Jan 1, 1976

By Valerio Violo, Antonio Raschilla, George Kafantaris

"The Cityringen project in Copenhagen, Denmark will form a new circular line in the city center and will consist of 21 new stations (17 + four transfer stations) and approximately 31 km (19 miles) of earth pressure balance (EPB) twin-bored tunnels.The new tunnels passed under the historical building of Magasin du Nord, McDonald’s and two pubs in the heart of the city with a minimum cover of about 4 m (13 ft).To minimize the movements, a complex system of compensation grouting and jet grouting soil treatment was performed. A detailed action plan between the parties involved allowed coping with the critical tunnel boring machine’s (TBM) successful passage.The Cityringen is an extension of the existing metro line underground Copenhagen and will include the City Circle Line, 15 km (9.5 miles) of twin tunnels looping around the city. The City Circle Line will form a new circular track inside the city center and will intersect the existing M1 and M2 lines at Kongens Nytorv and Frederiksberg stations, as well as suburban train services at København H, Østerport and Nørrebro. It will extend the Metro network to the Nørrebro, Østerbro areas and the central station at København H (Fig.1). The two new lines M3 and M4 will run on the same tracks, but the M3 will be a circle route running around the entire line, whereas the M4 will drive from the station to the north side of the city.The €1.5 billion design-build contract was awarded by Metroselskabet in January 2011 to the Copenhagen Metro Team (CMT), a joint venture (JV) between the Italian companies Salini, Tecnimont Civil construction and Seli SpA. Since the bankruptcy of Seli SpA and Tecnimont, Salini Impregilo now owns 100 percent of the JV shares. Seli Tunneling Denmark ApS, a subcontractor to CMT, was initially constituted as a Seli SpA subsidiary and, following the economic difficulties of Seli SpA, was acquired in 2015 by Salini Impregilo. Seli Denmark is in charge of the tunnels excavation and lining and owns the four 5.84-m (19-ft) diameter Seli/Kawasaki earth pressure balance machines."

Jan 5, 2017

By Joseph W. Siefke

The Kramer borate deposit is located in the western Mojave Desert at Boron, California, about 100 miles northeast of Los Angeles (Figure 1). The deposit derives its name from the district in which it lies. Borax (Na2 B407.10H2O) is being mined from the Boron open pit to serve a major portion of the United States and world borate markets. This paper deals primarily with those geologic factors which affect slope stability in the overburden at the Boron open pit. Discussion includes slope failure history, slope monitoring techniques and the results of a dipmeter survey of overburden structure. Open pit mining was begun at Boron in 1957. The initial pit was successfully excavated at the recommended 1.5:1 (horizontal to vertical) slope in the overburden. During pit expansion in 1962, excavation of the overburden exposed beds dipping into the pit at +15 degrees and numerous high angle fractures associated with two intersecting fracture systems, the West Jenifer and Portal fault zones. Ensuing south and east wall failures indicated the need for more structural information in the arkose to establish better wall design criteria. Barnard and Kistler (1963) recognized that the many facies changes, faults and other variables in the Boron overburden make it extremely difficult to reduce prediction of slides to a simple arithmetical formula. Despite the difficulties and uncertain¬ties, special programs such as surface resistivity, refraction seismic and core drilling were conducted in an attempt to predict slope stability conditions and to gather geologic information. These early efforts while helpful, did not provide the necessary details of bedding orientations and fault locations which are of paramount importance in our slope stability program. A dipmeter survey in 1974 successfully measured these variables and data from that survey are instrumental in the design of slopes currently being excavated.

Jan 1, 1976

By William M. Turner

Thermonics is a methodology of ground-water flow system analysis based upon the distribution of heat within the subsurface as influenced by moving ground water. Thermonics is based upon the Stallman Equation 1 (1) which describes the simultaneous transfer of heat through a porous medium which contains moving ground water. The Stallman Equation is:

Jan 1, 1980

By W. C. Meyer

A physical model of flotation, derived from viewing froth as a kinetic species since it constitutes the carrier of ore particles, not only agrees with and is simulated by engineering math models, but is statistically verified by actual laboratory flotation data. The model couples the mechanical removal of froth using paddles with the more rapid chemical interactions taking place in the bath. It clearly shows that the kinetics of mass removal is dictated by flotation cell dimensions, paddle speed, and, more importantly, froth characteristics. Some conclusions and predictions of the model are presented.

Jan 1, 1982

By D. B. Gentzler, J. L. Kohler

A method of monitoring production information (raw tonnage and machine state) from each working section has been developed. The method is based on the sensing of electrical parameters in each section load center, and the reporting of this information through the existing mine-wide monitoring system. A decision-theoretic type of pattern classification technique has been used to define the machine states. The basis of the method is presented in this paper, along with a proposed hardware and software implementation scheme. Information issues central to the development and use of the proposed production monitoring system are also discussed.

Jan 1, 1990

By W. W. Koczkodaj, J. Partyka

Beat exchange in an open air-water system is considered. The system incorporates a vertical cooling tower, and a horizontal multi-stage spray chamber with unlimited number of stages. Mixing of two streams of both water and air is permitted. A spread-sheet implementation estimates temperatures of outgoing water and air for given mass flow of water and air, factor of merit for heat exchangers, barometric pressure, wet- and dry-bulb temperatures, and the temperature of incoming water.

Jan 1, 1987

By Jasper D. Ward

The Indiana Limestone Company has developed an insulated, thin and comparatively light-weight pane 1 suitable for use as a spandrel panel in a curtain wall. The panel is about four inches thick and is composed of limestone backed with insulation. The inner surface of the insulation is protected with asbestos-cement board or a metal pan, depending on the type of insulation, building-code requirements and appearance (if the surface is left exposed). The limestone is cut to the size of the spandrel openings and the insulation and backup is applied in the mill ready to be shipped and in- stalled in the wall grid, A mortarless and waterproof joint with the metal frame components is achieved through the use of neoprene, thiokol, and caulking, The limestone is "dirt-proofed" (waterproofed) in the mill to slow down discoloration. The panel weighs more than some presently used materials. However, ILCO's architects and engineers have found that curtain wall systems capable of withstanding imposed wind loads are made up of sections large enough to carry this extra load of stone with little or no modification to the size of the metal frame. Limestone, a traditionally sound material, can be used in this new way without losing any of its natural qualities of dimensional stability, resistance to fire, and permanence.

Jan 1, 1959

By W. M. Ma, Daniel W. H. Su, K. Centofanti, Yi Luo, W. L. Zhong, Syd S. Peng

NTRODUCTION Surface subsidence monitoring is the most effective means for investigating the nature of, and developing the techniques for pre¬dicting the surface movement and deformation process. However, because of imperfection in survey equipment and field practices, the surface movement data collected from field survey are not error-free. Also due to lack of proper numerical techniques for computing surface deformation from the measured surface move¬ment data, a relatively large portion of the subsidence data col¬lected could not provide information other than surface movement. In a paper by Luo and Peng (1992), the sources and magnitude of errors in the measured surface movements using an electronic total station in subsidence survey are discussed. If the errors in the measured surface movement components are left untreated before calculation for deformation indices (i.e., slope, strain and curva¬ture), the errors will be carried over to the deformation indices and enlarged if improper numerical procedures are used in the calcu¬lation. It should be noticed that in protecting structures affected by ground subsidence, accurate surface deformation indices are much more important than surface movement. In order to improve the accuracy of the collected surface movement data and the calcu¬lated deformation indices, a number of numerical procedures are also proposed in the same paper. The proposed techniques include: a data smoothing technique for data pre-processing; and a number of numerical methods and/or procedures for calculating surface deformation indices from the measured surface movement data. DATA SMOOTHING Because of various factors, the measured surface movement data always contain errors, small or large. In order to better utilize the collected data, a data smoothing method is proposed to correct the errors in the measured movement data. The method uses the same concept as the influence function method (e.g., Knothe, 1957) on which many existing subsidence prediction methods are based. The data smoothing method makes necessary corrections on the measured movement for the point of interest according to not only the measured movement at this point but also those at the surrounding points. The contribution of a surrounding point in making the correction for the point of interest is inversely propor¬tional, in exponential form, to the distance between them. The new magnitude of a movement component at the point of interest (Zi*) is calculated by

Jan 1, 1992