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By G. Meschke

"This paper reports on computational and experimental research, performed at the Collaborative Research Center “Interaction Models for Mechanized Tunneling” at Ruhr-University Bochum, Germany. Research covers a broad spectrum of topics relevant for mechanized tunneling in soft soil conditions. This includes advances exploration methods and models for the characterization of the in-situ ground conditions, the interaction of the face support and the tail gap grouting with the porous soil, multi-scale models for the design of fiber reinforced segmental linings with enhanced robustness, computational methods for the numerical simulation of the tunnel advancement, the soil excavation and the material transport in the pressure chamber, logistics processes and risk analysis in urban tunneling.INTRODUCTIONMechanized Tunneling has proven itself as an economical and flexible construction method that continues to undergo a dynamic evolution process. Shield diameters continue to increase, and the application range of tunnel boring machines is being extended to an ever-increasing variety of geotechnical conditions. In order to maintain economic viability and to ensure an environmentally friendly construction process, realistic and reliable numerical models are required in order to make informed decisions during planning and construction. To provide a reliable numerical prognosis, it is necessary to accurately assess and understand the interactions between the components involved in mechanized tunneling with the surrounding site, the ground, and any pre-existing structures. Heterogeneous geological conditions and often only approximated ground parameters create, in contrast to other engineering projects, special demands. This necessitates new insights to new problems that can only be effectively solved through truly interdisciplinary research. To address these challenges, the German Research Foundation (DFG) has established the Collaborative Research Center “Interaction Models for Mechanized Tunneling” (SFB 837) at the Ruhr-University in Bochum in 2010. Collaborative Research Centers are interdisciplinary scientific research groups in which cooperative research is conducted under the umbrella of a central research theme. With a research budget of ca. 10 Million Euros for the second 4-year funding period, and a research team composed of 13 project leaders along with approximately 35 scientific assistants the SFB 837 is currently one of the largest research groups conducting fundamental research in tunneling related topics worldwide.RESEARCH TOPICSThe research topics of the SFB 837 encompass a number of relevant planning and construction related aspects in mechanized tunneling (Figure 1). These research themes are each supported by computational models and laboratory investigations and are all included in an SFB overarching Tunnel Information Model (TIM). Interaction groups integrate and combine the results of different submodels through prototypical cause-and-effect relationships, and through the analysis of the Wehrhahn metro line (WHL) project in Düsseldorf, which has been adopted as the reference project for the SFB 837."

Jan 1, 2016

By Stephen W. Denton

Planning a mining operation in Alaska will involve the investigation of many parameters common to mine planning anywhere. However, there are some unique circumstances that must be recognized when one considers development of mining operations in Alaska. This paper will not attempt to provide a blueprint for mine planning in Alaska, but hopefully will provide a better understanding of the truly unique nature of the northern latitudes. Given this understanding, the mine planner can better assess the potential hurdles along the road to a successful mining operation. The regulatory trend towards uniform standards for mining throughout the United States exemplifies the necessity for Alaska to prove its unique position in the natural resources picture. The factors which make Alaska truly different from the "Lower 48" can be summarized by four points 1) Remoteness and Size 2) Seasonable Extremes 3) Geologic Immaturity 4) Vegetation and Wildlife

Jan 1, 1984

By Kendrick C. Hardcastle

The practice of transporting an ore or matrix from a pit area to the plant process area by means of a hydraulic pipeline has long been used by the mining industry. The industries which have classically used hydraulic transportation of ore to the plant include the phosphate mining industry, the heavy minerals mining industry, the clay mining industry, and the sand mining industry. As the advantages of this method become better known throughout the mining industry as a whole, and as techniques and expertise improve, its use will undoubtedly spread. Its use is presently being contemplated in iron mining diatomaceous earth mining, and several industries where massive removal of overburden is a predicate to economical mining. The widely recognized advantages of hydraulic transport at ion of ore from the pit area to the mines are: 1) Its relatively low initial capital costs. 2) Its speed of relocation at the mine site. 3) The washing and scrubbing action given to the ore by its hydraulic passage into the pit pump and the subsequent trip through booster pumps down the pipeline to the plant.

Jan 1, 1969

By B. G. McNish

Neutron Activator Laboratory Analyzer used for Rapid Analysis for Ore Blending, Stripping, and Mine Control BAUXITE is a rock and not a mineral. Since it is a rock, its mineral content varies depending upon the parent material, the topographic location of the deposit and the severity of the weathering and oxidation processes which produced it. At Bauxite, Arkansas the major mineralogical constituent of the bauxite is gibbsite with ~IL- purities of silica, iron oxide, and titania minerals. Minor amounts of other minerals are found. Chemical composition varies from 45% to 60% alumina, 5% to 25% silica, 1% to 15% ferric oxide, and 1% to 3% titania. The Arkansas bauxite region is located entirely within the north- central area of the West Gulf Coastal Plain near the northwestern boundary with the Interior Highlands. The region trends northeast-southwest and is about 42 kilometers long. It is divided into two districts; one in Saline County and the other in Pulaski County. The Saline District is the most important since it has produced most of the bauxite. This district is located at Bauxite, Arkansas and the deposits are found around the flanks of the Saline Dome. It is roughly square-shaped and is about 190 square kilometers in area. The source rock for the deposits is a Late Cretaceous, grey, nepheline syenite.

Jan 1, 1979

By Harry R. Asche, Manfred K. Lechner

The Cross City Tunnel comprises 2km of a new underground traffic route in Sydney, Australia. The route is very complex, involving some six separate tunnels and three underground Y-junctions. For almost 200m the six tunnels run parallel at different level sunder William Street, Sydney. Almost all of the route runs adjacent to the City Business District of Sydney and adjacent to or below many major buildings and services. The planning and design of this project is described. The geometric arrangement is achieved with a strong dependence on 3D road design packages. Road alignment constraints include land acquisition and proximity to existing tunnels and basements as well as maintaining separation from the other tunnels in the scheme. Geotechnical and hydrogeological studies are described. Findings discussed include the high horizontal stress field in the Sydney area and investigation of incised palaeochannels on the route. Methods of design for the tunnels and Y-junctions are described, as well as methods of settlement prediction for the buildings and services. The latter includes the settlement assessment for more than 200 buildings, many in excess of 20 storeys, as well as services including all of the city railway lines in Sydney.

Jan 1, 2003

By Edgar Urbaez

Production scheduling is one of the most important factors affecting mine planning. A program -Mine Scheduler -that aids mining engineers with the setup of an optimum open pit production scheduling algorithm has been developed. A mathematical model for open pit scheduling that optimizes the Net Present Value of the cash flows was formulated. A simulated data is formulated as a Mixed Integer Linear Programming (MILP) problem. What's Best by Lindo Systems is used as the MILP solver in Microsoft Excel. The implementation of the algorithm focuses on problem setup, allowing users to easily evaluate, simplify, and develop the model that best fits their production scheduling.

Jan 1, 1999

By Pengfei Wang, Guorui Feng, Shufeng Zhang, Yuxia Guo, Tingye Qi, Dian Li

"Based on the geological conditions of the No. 10203 mining face of the Xinyang coal mine, a numerical model of the longwall backfilling face is built using the FLAC3D software to calculate the limit broken length of the key strata. Based on the deformation laws of the immediate roof, the backfilling parameters are determined. Furthermore, the movement laws of the overburden strata with different volume filling rates (0, 40, 60, 100, and 100%) and with different layout forms of the filling strip (under a volume filling rate of 60%) are analyzed. The results of the numerical modeling show that the stress of the two sides of the working face and the deformation of the overlying rock are gradually reduced with the increment of the volume filling ratio. In view of the deformation of the roof strata within the allowable range, a volume filling rate of 60% is selected to simulate and analyze the filling effect under different layout forms of the filling strip. The filling width, stress concentration area, and layout form of the filling strip are the key factors to control the movement of the overlying strata. In addition, the probability integral formula is used to calculate and predict the ground subsidence on the filling area, which confirmed that the backfilling mining method is fully applicable in the Xinyang coal mine. The results of this study provide a certain theoretical basis for the determination of the filling process in the field.INTRODUCTIONIn China and other coal producing countries, gob is managed using the caving, filling, supporting, and slowly sinking methods (Zhang, Zhou, and Zhang, 2009). With the continuing development of the concept of green coal mining (Guo, Deng, and Zou, 2004), the filling method, which is safe and environmentally friendly, has been widely used in the field. On one hand, this method could reduce waste rock and other waste discharge. On the other hand, it could effectively slow the surface subsidence. Recently, strip-filling mining mostly adapted the arrangement of the strip backfill with equal intervals and widths (Xie et al., 2004), but the reasonability of this arrangement should be discussed. To arrange the intervals and width of the strip-filling body reasonably, Feng et al. (2019) put forward the “constructional backfill mining (CBM)” concept. The CBM is a type of backfill mining with low backfill rate, strong structural stability, and good backfill effect. The targets of the CBM include the efficient usage of solid waste resources in mining areas to reduce the backfill cost, the improvement of backfill materials and backfill technologies to increase the backfill efficiency, and rational planning of backfill and mining scheme to reuse the underground mining space. The determination of proper width and intervals for the strip-filling body is the main content of the CBM. Strip-filling mining using cemented coal gangue backfilling is the main method to undertake overburden of the overlying strata and to slow down the surface deformation. It also plays an effective role in cost reduction (Xu et al., 2007). This study focuses on proper determination of the strip-filling body parameters according to actual geological conditions by a simulation. It provides an appropriate reference for backfill mining in the Xinyang coal mine."

Jan 1, 2019

By M. L. Leming

The mechanisms of Alkali-Silica Reactivity (ASR) are briefly reviewed, test methods are examined, and typical specifications are discussed. In addition, views on responsibility of the aggregate supplier regarding specifications are presented.

Jan 1, 1995

By Jr. Wilkinson

In today's work environment a tremendous amount of data is required to provide the regulatory agencies justification to issue a mining permit. The demands for data, specifically environmental characterization data, grow and the mine plans must address the issues raised by the interpretation of that data. Computers and computer software can provide operators and consultants with the tools necessary to assimilate, digest and interpret these seemingly unmanageable data sets. This paper presents some examples of how Mincom's MineScape software can be applied to the task of developing coal mine permits in an electronic format.

Jan 1, 1996

By G. A. Hufford

The cutoff grade applied to a disseminated orebody mined by open pit affects both the waste ratio, hence the cost of producing ore, and the ore grade, hence the quantity of metal recovered. As such it has a significant impact not only on the annual profit or loss, but also on the life of a mining property. Cutoff Grade Strategies Some commonly used objectives in calculating cutoff grades are as follows: Minimize Unit Cost of Product (1) This is found by adding all costs associated with each possible cutoff such as mining, processing, and marketing. This is divided by the quantity of marketable product obtained at each cutoff grade, then finding the minimum. Because the market value of the product does not enter the calculation it has no effect on this strategy: the same cutoff is selected in good times and bad.

Jan 1, 1986

By H. Kempton

New methods for remediating metals-contaminated groundwater include in-situ emplacement of highly adsorptive substrates to permanently retard solutes. Substrates are introduced by sequential injection of soluble components that precipitate in the aquifer, forming a permanent high-retardation zone. This method overcomes the factors that limit pump-and-treat remediation; i.e, long-term source loading and slow desorption. Column tests demonstrated efficient substrate emplacement, increasing retardation coefficients of Cr(VI) by 20 and As(V) by 40. Similar effectiveness is expected for other heavy metals. Simulations using a coupled advective-geochemical model accurately matched substrate emplacement and arsenic attenuation, allowing extrapolation to other constituents and larger-scale applications.

Jan 1, 1999

By Charles C. Mosher

An in-mine seismic technique for detecting faults has been tested in a Western U.S. coal mine. This technique has been used extensively in the U. K. to help guide longwall mining operations. Explosives detonated on the face of a seam generate sound waves which propagate into the seam. Reflections from faults are picked up by sensors on the same face. Computer processing is then used to determine the fault locations. A known fault was successfully located in this test. Modifications to the U. K. procedures were required for the relatively thicker roan and pillar mines common in the Western U. S.

Jan 1, 1983

By Thomas A. Earl

Strip mining of coal, and to a lesser extent limestone, gravel and other mineral deposits in the Appalachian region of the eastern United States has left many large and small areas of devastated land where mining predated reclamation requirements. In Pennsylvania alone, there are between 250,000 and 370,000 acres of strip-mined land 1,2/. A higher percentage, and a greater total acreage of land in Pennsylvania is in need of some form of reclamation than any other state, with the neighboring states of Ohio and Nest Virginia also having nearly the same magnitude of mining.2/ Recent legislation governing strip mining of coal proposed royalties to cover reclamation of such presently unusable land. However, in Pennsylvania and other states some progress has already been realized by utilizing abandoned strip mines and gravel pits for waste disposal sites. Given acceptable hydrogeologic settings, such use of these mined areas for landfilling has provided the incentive for ultimately restoring unreclaimed land to beneficial use, at no cost to the general public.

Jan 1, 1975

By W. K. Utt

This report discusses U.S. Bureau of Mines' research involving modem vehicle position determination techniques in surface mining. The applications would include haul trucks, power shovels, and drilling rigs. Accurate position determination of these vehicles in near real-time is expected to result in safer and more efficient mining operations. The requirements for a vehicle position monitoring and warning system were determined. After screening several concepts, the global positioning system (GPS) and a radar positioning system were selected for further evaluation. A state-of-the-art GPS receiver was taken to a surface mine to assess the feasibility of receiving the satellite signals. A state-of-the-art radar positioning system was evaluated with regard to accuracy.

Jan 1, 1995

By Richard L. Ash

Less than optimum production in mining always results when poorly blasted material is provided at loading points. More often than not the cause is due to blasting founds that fail to fully control and utilize explosive energy. In many cases the problem exists because too few blasters understand how blastholes actually break rock and recognize that blasting is a three-dimensional process in designing their blasts. To better understand how blasts can be more effectively designed the two major rock breakage processes are described. In addition, the respective contributions of the borehole and detonation pressures are defined as are the specific roles of the several important blasting design variables. The concept of stiffness as an engineering principle and its significance in blasting design is introduced for explaining the breakup of rock. Basic guidelines for affecting control over fragmentation and side effects like over-break are offered.

Jan 1, 1975

By Joseph G. Wargo

The purpose of this paper is to investigate trends in exploration expenditures of a selected group of mining companies for the interval 1968 through 1971. The paper also compares these trends with other financial factors that are associated with various groups of companies and comments on the implications of these trends. Although a four-year interval is hardly enough time to establish a long-range set of trends from which operating rules can be derived, the fact that the four years selected are in the immediate past gives some sense of relevance to the matter of exploration expenditures at the present time and in the near future. The sample under study here consists of 21 mining companies. Of these, 19 are listed on the New York Stock Exchange and 2 are listed on the American Exchange. Twenty are American, one is Canadian. All are fundamentally "mining companies" in that they derive the bulk of their income from the extraction, sale, and at times, fabrication of metals from their own mines. This is in contrast to companies which have mineral exploration departments but derive the bulk of their revenues from sources other than mining; for example, from oil and gas sates, Also, no companies which can be considered strictly as exploration companies are included in this study. Although this definition held up fairly well when studying this list in 1968, the strict application of this definition became more difficult through the years up to the present time. In 1971, three or four of the companies were changing their character in that they were phasing out of the mining business, and either deriving their income or planning to derive a substantial part of their income from activities other than mining. A study of

Jan 1, 1973

By J.N. Kohmuench

Teeter-bed (i.e., hindered-bed) separators are used throughout the mineral processing industry for both classification and density separation. The high capacity and sizing characteristics of these units make them ideal for feed preparation prior to coarse flotation (+0.100 mm) circuits. Teeter-bed separators are typically easy to control with two basic operating parameters, including fluidization water rate and bed level. However, data show that these two parameters greatly interact with one another. Given this finding, a high-level automatic control scheme was developed and implemented on a full-scale separator. In addition, dialogue with plant operators has led to several simple changes to an already established design that improves operational and maintenance characteristics.

Jan 1, 2010

By Dominique Francois-Bongarcon

The world mining industry is facing a severe recession. Thus, it is time to recall the value of geostatistical methods which were formerly developed as a money-saving and productivity-increasing tool. The situation has worsened, but the techniques of geostatistics have dramatically changed. Up to millions of dollars can be saved during exploration with simple use of variograms; then, during reserves estimation with kriging methods; and finally, with the parameterization of reserves, when evaluating a project and optimizing its global mining parameters.

Jan 1, 1983

By Vittorio Manassero, Antonello de Risi, Filippo Cavuoto

"This paper deals with an innovative mechanized method to bore and simultaneously line circular shafts, adopted in the Naples Metro project for the installation of 10 vertical shafts for ventilation purposes. With this method, excavation of shafts is carried out under a positive head of stabilizing fluid by a milling machine, temporarily set at the bottom of a permanent lining made of precast reinforced concrete segment rings. The debris is evacuated by inverse fluid circulation. The shafts in Naples are 4.5 m I.D., from 34 to 44 m deep and they are all located downtown in a highly urbanized area. They were bored and installed into volcanic soils under a hydrostatic head of up to 30 m. Displacements and groundwater level were constantly monitored to keep control of the effects on the surrounding buildings and utilities. INTRODUCTIONThe extension of Metro Line 1 in Naples (Italy) from the previous terminal of Piazza Dante to Piazza Garibaldi is also called the “low stretch”. Most of it runs along the coastline, encompassing the historical city center, the Greek-Roman Neapolis. The Metro Line crosses under densely urbanized areas for the whole way (Figure 1). It runs beneath Via Toledo, which follows the layout of the ancient Aragonese walls. The first station (Toledo) is located halfway along this street. Then, after a wide bend, the line reaches Piazza Municipio, where the second station is located. From there, the line moves along the axis of Via Depretis and Corso Umberto I, where the stations Università and Duomo are situated. The fifth station is in Piazza Garibaldi and the end of the stretch is located at the Naples Business Center. The twin single track tunnels were bored into volcanic tuff by TBM. This design choice simplified by far the construction of the tunnels and reduced to practically zero the interactions between tunnelling and surface buildings and utilities. Nevertheless, this choice entailed that the line had to be located at depths to the order of 35-45m below ground level and 30-35m below the water table. At each tunnel segment between stations, a pair of ventilation chambers were constructed (10 in total). Each ventilation chamber is connected to one TBM tunnel by a vertical shaft and a horizontal drift at the base of the shaft. The shafts, in addition to tunnel ventilation, provide a safety access/escape."

Jan 1, 2016

By John C. Nixon

In 1959, The Australasian Institute of Mining and Metallurgy (Aus. I.M.M.) was asked by the Federal Government of Australia and the State Government of South Australia to join in the formation and management of a new contract research organization which was subsequently named The Australian Mineral Development Laboratories (Arndel) ? This body was formerly the Research and Development Branch of the South Australian Department of Mines which had been set up to develop the Radium Hill uranium deposit. It had then gone into contract R&D and the State felt that it would be more appropriate for the Branch to become a separate national organization. The Aus. I.M.M. decided that a professional institute could not participate directly in Arndel and, as there was no other suitable industry group to do so, it formed the. Australian Mineral Industries Research Association Limited (AMIRA). AMIRA held its first Annual General Meeting in September 1959 when the first Council was elected and the Memorandum and Articles of Association were adopted. The initial task of AMIRA was to raise guarantees of work or cash from its members to underwrite Arndel for the first five years of operation. The Federal and State Governments also provided guarantees and Arndel commenced operations in January 1960.

Jan 1, 1977