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By Steven G. Vick, Herbert H. Einstein

1. INTRODUCTION The Tunnel Cost Model (TCM) is a computer based model whose objective is to quantify the risks of hard rock tunneling in terms of cost and time to completion. The main feature of the TCM is the simulation of the tunnel construction. The simulation makes it possible to incorporate in the time and cost computations the effect of uncertainties in geologic conditions and in productivity rates and costs. The cost and time computed with the TCM will be in form of distributions that allow a quantitative risk assessment. The TCM will be useful as an estimating tool permitting the estimator to rigorously relate uncertainties of individual factors to the end result. The TCM will also make it possible to evaluate technological innovations and to identify problem areas in existing technologies. The TCM consists of three interacting submodels: the geologic submodel, the construction operations submodel and the tunnel simulator. The goal of this paper is to describe the geologic submodel, whereas the construction operations submodel and the tunnel simulator will be described in the following paper by Moavenzadeh et al. First it will be shown how interactions between the geologic submodel and other parts of the TCM will impose certain requirements on the geologic submodel. These requirements, which relate primarily to the description of geologic conditions by a set of problem-oriented parameters and the quantification of uncertainty associated with geologic conditions, will then be discussed. This is followed by the description of the special structuring techniques -- decision tree and segmentation -- that are necessary to handle the great number of

Jan 1, 1974

By Paul Higley

Specialty Devices, Inc. and the CMRET/NIUST, University of Mississippi, have collaborated in the design and development of a new class of Robotic Underwater Vehicle (ROV) focusing on efficient, low cost, deepwater operations. The need for such a vehicle was driven by special requirements encountered in the establishment of the Gulf of Mexico Gas Hydrates Research Observatory at a depth of 850m in Mississippi Canyon Block 118 on a restricted budget. Requirements included deployment and recovery of tools and sensors and the connection of underwater-mateable electric and fiber optic connectors at depth. The standard complement of equipment required included; high-resolution video with lighting, scanning sonar, robotic arm, precision positionin and thrusters for limited transit and maneuvering. Conventional deep water ROVs are lowered in a large cage with a buoyant tether between the cage and the ROV. The tether is wound on a winch in the cage deployed as the ROV swims out from the cage. This cage is lowered on a large diameter umbilical cable with strength elements and communications elements and conductors for electric power. With increasing water depth the umbilical cable must become ever larger to accommodate increased power transmission loads and strength demands, with corresponding increase in deck handling equipment size and in turn, vessel size and overall cost. The surface ship must include a dynamic positioning (DP) system to control ship propulsion to maintain the position of the ROV cage at a position relative to the sea floor. DP ships with this capability and the ability to carry the large umbilical cable and winch are expensive.

Jan 1, 2008

By Wayne Hilgedick

Peabody Coal Company is the nation's largest producer of coal and is headquartered in St. Louis, Missouri. In 1978 Peabody divisionalized its operations to establish more responsive and effective mine management. Peabody Coal Company's Arizona Division operates two large surface mines, the Black Mesa and Kayenta Mines. Both are located in northeastern Arizona, approximately 30 miles from Kayenta, Arizona, on the Navajo and Hopi Indian Reservations. The Black Mesa Mine produces 4 to 5 million tons of coal per year and the Kayenta Mine produces 7 to 8 million tons per year. Coal from the Black Mesa Mine is transported 274 miles by coal slurry pipeline to the Mohave Generating Plant located on the Nevada/Arizona border at Bullhead City, Arizona. This plant is jointly owned by Southern California Edison, the Los Angeles Department of Water and Power, Nevada Power Company and Salt River Project Agriculture Improvement and Power District.

Jan 1, 1983

By Robert Labbe

The final tunnel lining for this project involved pumping vast quantities of concrete over large distances under the extremely busy streets of lower Manhattan. Approximately 68,000 cubic meters (89,000 cubic yards) were pumped from various locations over 152 meters (500 feet) below ground (Figure 1) to create nearly 14.5 kilometers (9 miles) of 3.05 meter (10 foot) diameter tunnel. Total distances pumped exceeded 1,645 meters (5,400 feet) horizontally after a vertical difference of over 152 meters (500 feet). The urban setting of the operation, coupled with the long distances over which concrete was pumped, created many problems which had to be dealt with along the way. A three-shift labor operation was implemented to allow sequential pouring of tunnel sections nearly every day. The fine tuning of the mix design was critical to make this operation successful.

By W. H. Schiffbauer

NIOSH has developed an active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) for warning workers as they approach known dangerous areas around heavy mining equipment and other dangerous work zones. HASARD is composed of a transmitter and a receiver. The transmitter generates a 60-kHz magnetic field using one or more wire loop antennas. Each antenna is adjusted to establish a magnetic field pattern for each hazardous area. The receiver, worn by the worker, is a magnetic field strength meter. The received signal is compared against preset levels which are calibrated to identify levels of danger. The receiver outputs can include visual, audible, and vibratory indicators and it can also be made to disable machine functions. HASARD was field tested on a Joy 12 continuous miner, a Komatsu 210 M Haulpak, and on a highwall launch vehicle. Slight modifications were made for each application. HASARD provided warnings as designed and proved to be rugged enough to withstand the harshest of production environments.

Jan 1, 2001

By J. Winterton

Cripple Creek and Victor Gold Mining Co. is developing a full-scale pad injection program as part of the overall operational plan for the Valley Leach Facility. As part of the development process the mechanics of the injection methodology are evaluated in the context of physical injection measurements, outcome from geophysical monitoring, and gold leaching theory. The results indicate that hydraulic fracturing analogies advanced heretofore do not accurately describe injection phenomena in unconsolidated and noncohesive material typical of leach pads. A new interpretation is presented and extended to define operational strategies for maximizing gold production.

Feb 27, 2013

By Y. J. Wang

This paper deals with the application of linear programming to the solution of mine ventilation network problems which involve only the controlled splitting of air. An airway whose air quantity is to be controlled to a prescribed value is called a "fixed-quantity" airway. In a network where the fixed-quantity airways are increased in number and are distributed such that the air quantities for the remaining airways are uniquely determined by Kirchhoff's first law, the problem reduces to determining the head losses and locations for air regulators and fans. This is one of the network problems encountered most often in underground coal mines. By formulating Kirchhoff's second law as a set of linear constraints and the total air horsepower supplied by fans as a linear objective function which is to be minimized, the problem is analyzed through the technique of linear programming. Some important properties of the problem are discussed and examples are presented.

Jan 1, 1971

By A. R. Wilde

The Muruntau gold deposit is situated in the Kyzyl Kum Desert of Uzbekistan. It is currently being mined in the world's largest open pit gold mine with production believed to be of the order of two million ounces per annum. The open pit measures about 3.5 by 2.5 km and extends to a depth of 350m. The gold ore resource in the Muruntau deposit, including production, is about 170 million ounces of gold (Anonymous, 1996). This paper presents a summary of the deposit geology and its regional geological setting. Information used in this paper has been generated from observations made on two visits to the mine and its environs, and a review of the Russian-and English-language literature.

Jan 1, 1999

By John C. Brower

Bolivia is nor a major gold producer but has produced continuously since pre Inca times. Production reached a peak in 1964 of about 4,000,000 grams and is currently about 1,000,000 grams. Production is mainly from the Tipuani River valley north of La Paz and is derived from Pleistocene basin fill: the Cangalli conglomerate and overlying terraces. Abandoned Pleistocene lake terraces south of La Paz in the Oruro area are another source of gold whose potential have not been realized. In both the Tipuani and Oruro areas, primitive hand methods are the principal means of production, with the exception of a single modern dredge. In spite of a long history of production, probably very little of the gold potential has been mined.

Jan 1, 1979

By Frederick McNeill, Mahmood Khwaja, Benjamin Lundsted, David Polcari, Michael S. Schultz, Timothy Clougherty

The City of Manchester, New Hampshire, is embarking on one of its largest public works projects in history to construct a 12,000 foot long, large-diameter, conveyance tunnel through downtown Manchester. This area has challenging geology with undulating bedrock (granite, schist, and gneiss) profile overlain by fluvial deposits. Understanding the subsurface conditions is key to mitigating project risks, establishing plan and profile for the tunnel, and selecting the most cost-sensitive and technically appropriate tunneling method. This paper presents the project team’s approach for conducting the ground investigation, developing preliminary subsurface profile, and the considerations for selecting the tunneling method.

Jun 13, 2023

By Robert L. Sundeen, Richard V. Wenberg

INTRODUCTION Shotcrete can be defined as spray-applied concrete with a maximum size aggregate in excess of 9.5 mm (0.375 in.). The concept evolved from guniting, which uses smaller aggregate and generally produces concrete with poorer physical properties. The larger aggregate used in shotcrete requires less water in the mix, while offering larger bonding surfaces, thus imparting greater tensile and compressive strengths. TYPES OF MACHINES Two basic designs of shotcrete machines in general use are the wet or prehydrated zero slump and low slump type, and the dry or nozzle hydrated machines. Fig. 1 shows a typical zero-slump machine in a con¬figuration commonly used for small-volume require¬ments. The prehydrated zero-slump machine mixes exactly proportioned batches in a sealed pressurized chamber. "Slugs" of hydrated shotcrete mix and com¬pressed air are sent through a distribution hose to the nozzle where the wet mix emerges as a spray. The spray is directed onto the rock surface by the nozzle operator. The low-slump machine is similar, except that a thick slurry mix of aggregate is delivered throughout the distribution hose to the nozzle. Fig. 2 shows a typical low-slump shotcrete machine used in moderate-volume applications. The nozzle-hydrated shotcrete machine accepts a premixed "dry" (4 to 6% moisture) batch of aggregate and cement. A constant feed of this mix is directed by compressed air through the distribution hose to the nozzle. At the nozzle, water for hydration is introduced into the emerging spray. The hydrated mixture is di¬rected onto the rock surface by the nozzle operator. Fig. 3 shows a typical dry-mix machine. The major difference between the two basic machine designs is the consistency of the shotcrete quality. Pre¬hydrated machines have high degrees of consistency and produce high-strength concrete, resulting from their ability to produce exact mixtures of zero or low-slump concrete within the machine. Nozzle-hydrated machines tend to produce poorer quality concrete because of the difficulty in controlling the water content at the nozzle. Water input essentially is an art. As such it is not precise, and the shotcrete produced is of variable quality. MATERIALS HANDLING Materials handling presents a problem to either type of shotcrete machine. At times considerable quantities

Jan 1, 1982

By W. R. Dengler

INTRODUCTION Shaft sinking represents a relatively small proportion of the activities involved in mine development. Because of this limited utilization, shaft sinking has been one of the most difficult functions to mechanize. Although shaft machines (muckers) were introduced more than 30 years ago, the first machines were low-capacity units, and machines of this type did not gain wide acceptance by the mining industry until the late 1950s. However, the increasing depth of underground mines and the es¬calating costs of labor have increased the benefits obtain¬able from high-speed shaft sinking. The result has been a growing need for high-capacity shaft machines. Most of the machines available at the present time have been developed by modifying existing equipment to increase the payload capacity and performance. AVAILABLE SHAFT MACHINES In general, shaft machines may be classified accord¬ing to the types of digging mechanisms and the mecha¬nisms of operation. The available digging mechanisms include clamshells, cactus grabs, front-end buckets, and backhoes. The mechanisms of operation can be classified as either pneumatic or hydraulic. Selection Criteria For efficient operation, the primary consideration in selecting a shaft machine is its capacity. The minimum capacity of the machine should match the capacity of the hoisting system at the ultimate depth of the shaft. In many cases, two machines may be needed to obtain a sufficient mucking capacity. The shaft dimensions and configuration often dictate the type of machine that may be utilized; for example, an overshot loader does not work well in a circular shaft that has a diameter of less than 5.5 m (18 ft). Similarly, a single Cryderman mucker is not suitable for a large-diameter shaft, nor is it applicable where very high sinking buckets are to be used. Other factors for consideration include the degree of material fragmentation, the abrasiveness of the rock, and the amount of ground water that is inter¬sected. Machine Descriptions Riddell Mucker: The Riddell mucker, illustrated in Fig. 1, was first introduced in 1948. This is one of the most common shaft machines in the medium-capacity range. The Riddell mucker consists of a hoisting and traveling mechanism that operates a clamshell suspended on cables. The early machines operated with a 0.3 m3 (10 cu ft) clamshell and had an hourly capacity of approximately 27 t (30 st). This type of shaft machine has gained wide acceptance throughout North America. Essentially, the Riddell mucker consists of standard components, such as the pneumatic tugger hoists that operate the clamshell. The carriage is suspended on rails that also serve as the blasting set, located immediately below the shaft timbers. To effectively position the clam¬shell in the shaft, the operator controls the carriage travel by means of wheels that are driven by a pneu¬matic motor. The Riddell mucker most commonly is used in rec¬tangular timbered shafts. However, some units have been installed with circular rails, allowing them to work in circular concrete-lined shafts. A popular practice with many Riddell muckers is to increase the capacity through the use of larger clamshells, often ranging up to 0.76 m3 (1.0 cu yd), in conjunction with more powerful tugger hoists. In some large rectangular shafts, two Riddell units have been used side by side to achieve a sufficient capacity. Cryderman Mucker: The Cryderman mucker, illus¬trated in Fig. 2, is another common shaft machine in the low- to medium-capacity range. Developed in the early 1950s, it also has gained wide acceptance throughout North America. Equipped with a 0.3 m3 (10 cu ft) bucket, the Cryderman mucker has an hourly capacity of approximately 23 t (25 st). The Cryderman mucker is operated entirely by means of pneumatic cylinders and a pneumatic telescopic boom. The boom is suspended from a sectional frame¬work that is usually located at one end of the shaft. The framework or headframe can be suspended from an independent hoisting system located either on the sur¬face or in the shaft. In large shafts of either rectangular

Jan 1, 1982

By Stephen G. Hardcastle, Michel G. Grenier, Kevin C. Butler

Today there are numerous electronic rotating vane and thermal (hot-wire) anemometers, as well as vortex meters available to measure air velocity. Of these, a laboratory and field evaluation has found that certain instruments are better suited to routine airflow measurements in mine roadways and ventilation ducts. This paper concludes a study sponsored by the Atomic Energy Control Board of Canada, that was introduced at the 5th U.S. Symposium. The study investigated the suitability of currently available electronic anemometers as replacements for the traditional mechanical analog devices while maintaining standard methods such as the continuous traverse. Six electronic instruments were subjected to extensive tests under controlled conditions both in a wind-tunnel and in the field at an underground mine. The evaluation concluded that ergonomics and design were major considerations in unit preference as most of the instruments had very similar performance characteristics. Specific findings were: a) In the wind-tunnel the vane anemometers, especially the "micro" vanes, were more susceptible to misalignment or yaw effects but these were not noticeable in the field; b) Both the vortex and hot-wire anemometers were suitable for continuous traverses of mine roadways; c) Traversing ventilation ducts was more practical than a Pitot-tube multi-point assessments or discharge measurements; d) Yaw is a major concern in duct measurements; e) The continuous traversing method for roadways overestimates the average air velocity; f) Hot-wire anemometers can require significant air density corrections; and g) Hot-wire anemometers are better suited than rotating vanes to mine roadways of less than 1 m/s average air velocity. Based on research detailed in this paper, the ventilation engineer should be able to match the mine's requirements with the presented instrument performance characteristics, thereby optimizing the purchase of a new anemometer and the efficiency with which air velocities are measured.

Jan 1, 1993

By E. S. Smith, Sunirmal Banerjee

INTRODUCTION Social awareness of the detrimental impact of man-made wastes on our environment has grown considerably during the last two decades. Increased public and institutional concerns have resulted in the implementation of a wide variety of regulatory controls of disposal of wastes. These regulations have often reflected significant conservatism in expecting guaranteed elimination of pollution risks. This sort of expectation assumed a state of knowledge which was not readily available to the major producers of wastes. The mining industry, in particular, has been affected by such regulations in terms of excessive costs and loss of benefit. As a result, investigations are in progress (1) to generate newer methods for satisfactory stabilization of mine and mill wastes and (2) to apply the available technology to achieve the standards set by the regulatory agencies at reasonable costs. This paper presents a conceptual scheme for stabilization of mill wastes by suitable management of operations and accelerated consolidation of tailings slurries. The main discussion in this paper is aimed at the ability of the proposed scheme to address the major considerations in effective disposal. Comparison in both cost and effectiveness are also made between the proposed scheme and various other currently used disposal concepts. MAJOR CONSIDERATIONS IN EFFECTIVE DISPOSAL The primary objective of an effective tailings disposal scheme is to provide containment of the contaminants in such a manner that the undesirable impact of the wastes on the three basic elements of our environment--land, air, and water-would be minimal. Bearing the above objective in mind, one may justifiably list the major considerations in the choice of the disposal scheme in terms of its effects on land, air, and water (Bromwell, 1976) as follows: Effects on Land (1) whether the scheme makes optimal use of land.

Jan 1, 1980

By A. Santha Ram

The Indian Mining sector is subjected to a number of trends including call for global transition towards the route to sustainable development. Several regulations were enacted by the Government departments, from time to time, in order to identify the problems faced by the mining industry, including small-scale mining operations and to suggest appropriate mitigation measures in the form of environmental standards and certifications. During this process, a pursuit of sustainable development is regarded as an important area responding to socio-economic conditions, priorities and thus guides eventually corporate policies and practices. Thus, there is a need to formulate strategies for sustainable development. Based on these strategies some environmental indicators were developed in order to track down the progress and to evaluate its success. A case study pertaining to a group of iron ore mines in North Goa and Chromite mines in Sukinda, Orissa was selected for this study. Base line environmental data has been generated in the respective study sites. A core set of environmental indicators monitoring environmental progress based on the P-S-R model pioneered by OECD is linked with indicators for assessing the integration of environmental concerns.

Jan 1, 2003

By Roberto J. Guardia, Robert A. Robinson, John Wilkerson, Wick Haxton

Several candidate sites have been proposed for the Deep Underground Science and Engineering Laboratory (DUSEL), a facility that would provide over 2000 meters of overburden to screen out cosmic rays that would otherwise interfere with experiments. Types of anticipated experiments include: detection of dark matter and stellar neutrinos, and evaluation of deep microbial life forms. Engineering experiments might include more refined scanning devices to “see” rock defects ahead of tunneling, improved predictive models for groundwater inflows and tunnel support requirements, and improved instrumentation for monitoring in-situ stresses, rock deformations, and pore water pressures. Spin-offs from this research might include more sensitive security detectors for scrutinizing shipping containers, new drugs based on new microbes, and improved sensor systems for tunneling. A site near Leavenworth, WA, was assessed and shown to have numerous topographic and geotechnical advantages. Rock cover is on the order of 2250 meters. The granitic bedrock is suitable for tunneling a variety of large underground openings.

Jan 1, 2005

By T. Leftwich, G. Faison, K. Pavlich, R. Borden, S. Pavlou

Recent regulatory and policy initiatives under the Resource Conservation and Recovery Act (RCRA), and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), will have a significant effect in risk reduction requirements for the mining and minerals processing industry. For example, Congress is considering regulating 20 special wastes from the processing of ore and minerals through RCRA Subtitle D and TSCA. The performance of risk analyses and environmental planning at mining projects is often driven by Federal and state regulatory standards. Recent regulatory and policy initiatives by the Environmental Protection Agency under the Resource Conservation and Recovery Act (RCRA), and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), will have a significant effect on environmental planning and risk reduction programs for mining and minerals processing. Regulatory programs implemented under other Federal laws including the Safe Drinking Water Act, Clean Water Act, and Clean Air Act will also impact industry practices. This paper provides: 1) a brief overview of mining waste and mining waste management, and 2) a description of these regulatory initiatives and a discussion on the impacts of new requirements on environmental and risk reduction programs in the mining industry.

Jan 1, 1992

By G. L. Barthauer

It is a distinct privilege to have the opportunity of addressing this group today. Although I, myself, am not a mining engineer, I have always had profound admiration and respect for those of you who each day live and work according to the tenets of Murphy's Law. Murphy, as some of you may know, was an Irish philosopher whose sole contribution to his field was the observation, "In the mining industry, if anything can possibly go wrong, it will!" You have heard this afternoon a variety of papers, touching on or describing in some detail imminent problems which presently face the coal industry. Many of these problems show no signs of diminishing. Actually, there is good reason to believe that they will intensify as governing bodies pass additional enabling legislation and regulatory agencies adopt more stringent "Rules and Regulations". In many cases, these groups are seemingly oblivious or indifferent to either cost factors or technical problems involved in achieving the desired goals.

Jan 1, 1967

By Timothy C. Richmond

The Stillwater District is located in south central Montana approximately 75 miles southwest of Billings, the state's largest city. It lies along the northeast front of the Beartooth Mountains and is within the boundaries of the Custer and Gelatin National Forests. The district contains some of the nation's most spectacular mountain scenery. Montana's highest peaks, including 12,799 foot Granite Peak, rise a few miles south of the area. Much of the district is located on a gently undulating plateau which averages 8500 ft. above sea level, broken by hills up to 10,000 feet and slashed by glacially carved canyons, some of which are more than 3,000 feet deep.(Fig. 1) Immediately to the north and east, the land falls away to the Great Plains, stretching unbroken to the Mississippi River. Two major tributaries of the Yellowstone River, the Stillwater and Boulder Rivers, traverse the area and several large streams originate in the district itself. Access to the high mountain country and the adjoining Beartooth Primitive Area is restricted to a few horse and jeep trails continuing from the terminus of improved roads in the bottom of the Stillwater and Boulder Valleys. Hunters, fishermen and cabin owners make intensive use of the area along its improved transportation routes, but hikers seldom venture more than three miles beyond the end of the roads. People from the Billings area are the most frequent visitors.

Jan 1, 1974

Slurry technology developed for the marine transport of mineral commodities has been increasingly applied to on-shore slurry transport systems. Reclaim of mineral concentrates, sand tailings for mine backfill and various industrial minerals from storage tanks or ponds normally require a slurry of high density at constant flow rates to improve process performance and to reduce handling costs. An efficient system must accomplish this at minimum capital costs with maximum reliability. Continuing improvements in equipment design to improve repulping efficiency and their application are discussed.

Jan 1, 1986