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By Özgür Bezgin

This paper presents observations on the installation of drilled shafts from two construction projects and an academic study with experimental and analytical parts. The construction projects involved the use of pressurized drilling methods. The experimental part of the academic study involved the use of the auger drilling method. The analytical part of the academic study investigated the effect of drilling methods on the soil-structure interaction and the behavior of drilled shafts under lateral loads. The concept of ?free-length? is introduced for the lateral load design of pressure-drilled shafts that are thought to be fully embedded within a soil media. The academic part of the study presented herein was conducted in Rutgers, the State University of New Jersey.

Jan 1, 2009

By J. N. Murphy

The use of the National Science Teachers Association (NSTA) regional meetings as a forum to educate teachers on the role of minerals in our society has been immeasurably successful. Each year, on average about 3,500 to 4,000 teachers participate in each of the three regional NSTA meetings. At each of these meetings, nearly 2,000 teachers visit the “Minerals Coalition Booth” and receive free mineral samples and other educational support materials. Some rules of thumb for a successful booth at the NSTA are provided. Considering the level of effort for such a booth, are there alternatives? The NSTA also organizes a national annual meeting with attendance of about 20,000. All who have participated in a regional NSTA agree that the traditional approach of providing a mineral set and teacher materials for a substantial fraction of the 20,000 attendees is not feasible. Conceptual alternatives for minerals education at the national NSTA meeting are introduced and evaluated.

Jan 1, 2001

By N. Barton, E. Quadros

This paper addresses the prediction of groutable joint apertures, grout penetration limitations, and possible grout take volumes per cubic metre of rock, as a result of 5 to 10 MPa pre-injection pressures ahead of tunnels. Joints are obviously opened more than in the preceding Lugeon tests, and many rock mass properties can apparently be improved if stable micro-cement based materials are used. Cet article concerne la prédiction des ouvertures des fractures injectables, les limites de pénétration du coulis et les volumes injectés par mètre cube, d’après les résultats des injections à l’avant tête des tunnels sous pressions de 5 à 10 MPa. Evidemment les joints s’ouvrent plus que dans les essais Lugeon précédents. Maintes propriétés du massif peuvent apparemment être améliorés si l’on emploi des coulis a base de micro-ciment stable. Die Publikation widmet sich der Prognose injizierbarer Kluftöffnungen, Grenzwerte für Injektionsreichweiten und erreichbarer Injektionsvolumen pro Kubikmeter injizierter Fels, durch die Anwendung von 5 bis 10 MPa Vorinjektionsdrücken vor der Tunnelfront.Die Klüfte werden offensichtlich weiter geöffnet als in den vorhergegangenen Lugeon Versuchen und mehrere Felsparameter können durch die Verwendung von stabilisierten Micro-Zement basierten Injektionsmaterialien verbessert werden.

Jan 1, 2003

By Edward (Ted) M. Dowey

Shaft 26B of New York City’s Third Water Tunnel was constructed by Frontier-Kemper Constructors, Inc. of Evansville, Indiana. The 176.8 m (580 ft) deep shaft will serve as the construction shaft for the Manhattan spur of Water Tunnel No. 3. Twelve m (40 ft) of over-burden was supported by a rectangular cofferdam. This shaft was excavated in 13 months, through 164.6 m (540 ft) of rock, using 24,040 kg (26.5 tons) of explosives. Concrete lining cycles included the installation of stainless steel pipes embedded in the lining as the shaft advanced. A total of 635 m (2,084 linear feet) of stainless steel pipe was installed.

Jan 1, 1997

AUSTRALIA CHAPMAN Gary JOHN WAGSTAFF CONTSRUCTIONS PTY. LTD. 1 Ashgrove Crescent 4060 ASHGROVE BRISBANE HILLAR Jaaes Director J.A. HILLAR & ASSOCIATES 99 Woolwich Road WOOLWICH, NSW 2110 WAGSTAFF John Managing Director JOHN WAGSTAFF CONSTRUCTIONS PTY. LTD. 1 Ashgrove Crescent 4060 ASHGROVE, BRISBANE AUSTRIA FUCHSBERGER M. TECHNISCHE UNIVERSITAT INSTITUT FUR BODENMECHANIK Rechbauerstrasse 12 8010 GRAZ

Jan 1, 1994

By H. Foster Bain

The war has brought about many changes in the Western States, and some have deep pr sent or potent al economic significance. The West has been feeling severe growing pains for a number of years. Especially since the beginning of preparation for national defense and through the period of

Jan 1, 1945

It cannot be said that accurate and reliable ore reserve estimation is the fundamental of any mining operation success. Estimation techniques which are used to estimate the grade distribution of an orebody together with the assessment of uncertainty and risk have a vital influence on the success of any optimisation algorithm. Traditional estimation techniques such as kriging or inverse distance weighting are frequently used for assigning grade values to blocks. Various attempts have been made in order to compare geostatistical estimated methods for ore reserve estimation. This paper aims to evaluate the sensitivity of different estimation methods over changing the block dimension. For this reason, several block models with different dimensions were derived in Chador Malu iron ore mine which is located in 180 km northeast of Yazd in the centre of Iran. Each block model was estimated by different estimation methods such as nearest neighbours (NN), inverse distance (ID) and ordinary kriging (OK). The results of each estimation methods were compared against a control block file created by using the assay results of all blastholes drilled in the ore over four benches of the pit. The results signify that by estimating the large block size, no significant improvement occurred due to the employment of different estimation techniques. Furthermore, the grades estimated based on ID method is more reliable, but OK methods estimated more accurate tonnage.

Dec 6, 2010

By Vincent Jue

In December 2009, the Italian High Speed Rail Network AV began running over the full 1000 km system length from Turin, at the foothills of the Alps to Salerno, on the seacoast south of the volcano Mt. Vesuvius. It runs through Alpine rivers, highly seismic active zones, mountains, river plains, and through some of the most densely populated areas in Europe as well as some of its most expensive real estate. The Italian High Speed Network?s technical/economic constraints and its regulatory/socio-environmental concerns well may mirror similar obstacles set to confront the nascent California High Speed Rail Program. The two types of constraints must be dealt with together to reach the best construction solution. It is estimated that more than 20% of Italian High Speed Rail Network costs were spent on ground engineering including over 150 km of tunnels, 200 km of viaducts and bridges and 650 km of embankments and trenches. However, it also is estimated that 25% of costs were spent on social and environmental integration of the new rail lines including over 6 square miles of green offsets, 160 km of anti-noise walls, and 300 agreements for socio-environmental work. This paper will look at four examples of innovative ground engineering solutions, each with its own intricate set of constraints: ? Foundation system for viaducts across the ?Po? and ?Ticino? rivers. ? Soil consolidation under railway embankments ? Requirement of short tunnels for physical and environmental reasons ? Construction of railway stations in a confined right of way

Jan 1, 2010

By Frank Callanan

The Ameristar Casino expansion project included the design and construction of a 25-story hotel and 9-story parking structure expansion. The site is located in a floodplain on the banks of the Missouri River in Saint Charles, Missouri, where the underlying soils are potentially liquefiable. The geotechnical engineer performed subsurface exploration and analysis, which included site-specific seismic response and liquefaction, and provided geotechnical design recommendations. In the event of an earthquake, post-liquefaction settlement was calculated to be approximately 14 inches. Additional project constraints included wetlands protection, construction adjacent to the existing facility, flood protection and river bank stability. Because of the liquefaction issue, the geotechnical engineer consulted with a specialty geotechnical contractor on ground improvement methods. This consultation led to a proposal to eliminate deep foundations from the design and support the structures on shallow and mat foundations. The geotechnical engineer assisted the design team with foundation design analysis and value engineering assessments. Together with the project team, the geotechnical engineer used the data to evaluate foundation options and construction methods to overcome the site challenges and concluded that ground improvement was the optimum course of action. Because of the nature of the site constraints, a number of ground improvement methods were needed. The geotechnical engineer evaluated the methods proposed by the geotechnical contractor and provided the technical specifications for the ground improvement bid package, which included vibro-compaction, compaction grouting and micropiles. The ground improvement allowed for the use of shallow foundations (mat and spread footings), which provided the client with significant time and cost savings over the deep foundation alternatives.

Jan 1, 2009

By Vinay Kumar Agrawal, Rama Nath Praharaj

IMFA Group is the largest producer of Charge chrome not only in India but also in Asia. This Group has plants situated at Therubali and at Choudwar. They also have a Thermal power plant at Choudwar which not only caters to the power requirement of Choudwar plant but also supplies power to Therubali. The plants are fed for Chromite ore through the captive mines namely Nuasahi Chromite mines (40.47 Ha) , Bangur Chromite mines(37.34Ha), Sukinda chromite mines (116.76 Ha), Mahagiri Chromite Mine(73.777 Ha) and Chingudipal Chromite mines (26.62 Ha). Nuasahi Chromite Mine, which is situated in Keonjhar district, is an underground mine and is based upon best technological advancements in the industry. The underground mining operation is certified under ISO-9002, ISO-14001and OHSAS 18001. This not only shows the concern for the quality, environment but also for the health of the employees. The Nuashahi is the first chromite mine to backfill the opencast excavations created during the last 50 years and carry out the production from underground area below the opencast workings. This paper deals with the state of art technology of sub-level open stopping in thin ore bodies. The under-ground mine openings was started in the year 1997. In next four years the production of chromite from underground was started.(2001). At present the mine is in a good shape with several running stopes. Today it is producing around 10,000 Mt per month of chromite. The development of the mine is carried out with an average of 200 mtr per month of tunneling. The mine is having a mechanical ventilator having a capacity of24000 M3 per hour at 50mm water gauge, thus feeding sufficient air for the persons working in underground. The mine is being dewatered through a most modern positive suction sump, having a capacity of 500 cum and operated with 120 HP pumps. After commissioning of this sump in the year 2003, the mine has taken a quantum jump in production with remarkable saving in power consumption.

Jan 1, 2007

By M. N. Bassim, W. W. Tennese

"Concepts of linear elastic fracture mechanics were applied to study two cases of failure, namely an equalizing beam from a tandem rear axle of a highway tractor unit and the main beam of a flat bed trailer. In the first case, the presence of a crack, initiated by stress corrosion cracking followed by significant fatigue crack propagation produced a state of stress which was sufficient to produce brittle failure. Calculation of the fatigue life agreed with the number of cycles that the structure experienced before final fracture. In the second case, it was demonstrated that a combination of low temperature and high loading rate was sufficient to cause brittle fracture.IntroductionFailure analysis of engineering components has generally been carried out without the benefit of fracture mechanics. It is generally understood that real structures inevitably contain internal or surface flaws which under an applied load, may propagate to fracture. Fracture mechanics relates the applied stresses to the crack size in specified geometries. Since its introduction approximately thirty years ago, fracture mechanics has evolved as a design philosophy which can be used to develop fracture-safe designs. It can be also applied in analysis of failures, to ascertain if sound design and fabrication methods have been used."

Jan 1, 1985

By Brett Campbell

The San Vicente to 2nd Aqueduct Pipeline?Tunnel project is a raw water conveyance tunnel linking the San Vicente Reservoir (SVR) to the 2nd Aqueduct Pipeline via Rancho Penasquitos Pressure Control Facility (RPPCF). This 58,230 lf long tunnel will be 8.5? final ID, and has four points of construction access. The job is classified into 6 Reaches of tunnel, identified by the dominant geology within the reach. This paper will focus on Reach 3, specifically the measures necessary to drill and blast a 550 lineal foot section of granitic rock tunnel immediately in front of an open face digger shield.

Jan 1, 2008

By Jackson R. Pressley, M L. Hopkins, R E. Danell, N T. Moxon, Andrew Bowman

Efficient and cost effective blasting is achieved by closely matching the explosive energy to the strength of the material in which it is being used. Although there are many empirical relationships wich approximate this situation complete the blast optimization can only be achieved by quantitatively assessing explosive/rock interactions and explosive performance. The performance of an explosive is essentially governed by its velocity of detonation or the rate at which the detonation wave travels through the explosive column.

Jan 1, 1991

By A. K. Mukherjee

The roles of pulsating mechanisms such as the amplitude and frequency of the jig cycle are well established in jigging. Also well established are the roles of the size ratio and the volume fraction of the feed. In iron ore beneficiation plants, these process parameters are optimized to achieve the highest efficiency. However, the role of one of the more important feed characteristics, the liberation characteristic of the feed, has not been studied in detail. Evaluation of the liberation characteristics is difficult because the required washability test is not viable for iron ore feed. In this paper, a new method is proposed in which the liberation characteristics are measured through a separation efficiency value. In the new evaluation method, jigging parameters such as amplitude and frequency of the jig cycle are optimized from the fundamental understanding of the process dynamics and feed characteristics such as size distribution. Then, feeds with different liberation characteristics are tested to evaluate the liberation characteristics of feed in jigging.

Jan 1, 2008

By J Webster-Brown

The Tui Mine is an abandoned Pb-Zn mine giving rise to water quality problems in the Te Aroha region of Coromandel, New Zealand. When sampled in September 2002, for example, both the Tui and Tunakohoia Streams draining the mine site exceeded ANZECC (2000) water quality guidelines for aquatic life protection (Cu, Cd and Zn) and recreational quality (Cd). Based on trace metal mass flux (kg/yr) from parts of the mine site, the principal pathways by which Cu, Zn and Cd contamination reach these streams have been identified as:the tailings dam leachate,the diverted stream water from above the dam,the drainage from Adit 5 (which accounts for 95 % of Zn and Cd contamination in Tunakohoia Stream), andto a lesser extent, run-off from waste rock piles below Adit 4 level. Of the various remediation options, which have been proposed for the site, the following are identified as providing the best protection for the Tui and Tunakohoia streams:stabilising the tailings dam embankment and capping the embankment and tailings,constructing and/or cleaning out engineered diversion drains around the perimeter of the tailings dam to divert surface water away from the tailings dam, andinstalling bulkheads within Adit 5. A formal postal survey of the people of Te Aroha (66 respondents from 230 surveys) indicated that their priority was that the site be made safe for the public to visit, and used for recreation. As soil samples in potential recreational areas of the mine site, significantly exceeded guideline values for Cu, Pb, Zn, Cd and As, soil removal or capping clearly also needs to be part of a remediation plan. Development of the site as a historical/ecotourism area was viewed favourably, as this may encourage more visitors to the Te Aroha area as well as educate local residents.

Jan 1, 2003

The selection of the best comminution circuit for the preparation of concentration feed is a compromise based on economics, energy efficiency, labour costs, steel consumption, availability and other factors specific to each case. It is postulated that the selection must be a choice of one of the eight basic comminution circuits which can be divided into two basic groups, (1) autogenous or semi-autogenous primary mills with or without a secondary grinding stage and (2) fine crushing usually in cone crushers followed by a rod mill-ball mill circuit or a single stage ball mill circuit. The accuracy of selection may be improved by pilot plant and laboratory tests which are described in this paper. For (1) above, testing includes media competency tests with standard impact crushing, grindability and abrasion tests followed by pilot plant tests. For (2) above, bench scale crushability, grindability and abrasion testing is available. It is suggested that, through these tests, it should be possible to eliminate all but one in each group of basic comminution circuits. Then engineering and economic studies should lead to the best comminution circuit for the specific requirement.

Jan 1, 1984

By Mark N. Savit

It is indeed a rarity for a non-engineer, let alone a lawyer, to even be considered for a mining-related award, especially where that award is for significant contributions to technical progress in the mining and exploration sectors. So, when I was notified that I had received this award, I struggled for a topic that would meld the legal world that I operate in with the engineering driven world of exploration and extraction. The most exciting part of my job has always been the opportunity to absorb the technical details of the cases I work on and, in effect, translate them for a lay audience. Too often, I have found, lawyers, judges, legislators and yes, even regulators who lack a technical background simply give up trying to understand the details of the very conditions or processes that they are trying to describe and simply repeat phrases told to them by their client or by a retained expert.

Jan 1, 2008

By W. J. Kennedy, John D. Gardner

Introduction During the past 10 years, energy costs in mining have risen from about 4% to as much as 25% of total production cost. When combined with declining ore grades, these costs exert inordinate stress on mine productivity. Industrial engineering techniques have traditionally been aimed at improving manufacturing facilities productivity, but they have been applied to mining as pressure for productivity improvement has increased. These techniques can perform four useful functions for mining operations by improving methods, equipment selection procedures, energy use through scheduling, and managing energy costs rather than being managed by them. This article discusses some of the standard techniques for productivity improvement, and how they can be adapted to perform these four functions. Pre-Production The best time to seek high productivity is when a mine is being planned. During pre-production, when most options are still open, an optimum mine design is achievable. At this time, major equipment selections are made, the layout, material handling systems, and processes are designed, and critical energy source decisions are made. By including explicit energy cost projections, decisions can be made that will save significant amounts of money per ton of ore over the life of the mine. Attention can also be given to often overlooked details such as lighting. Some of the same tools used in new mine planning are applicable to productivity improvements at an existing plant. These tools are the charting and modeling methods that have been developed by industrial engineers over the past 75 years. Energy Consumption Before any analysis of energy consumption can be performed, preliminary work is necessary to find the kind of energy used, how much it costs the plant, and when electrical peaks occur. Past bills should be examined to determine the monthly consumption rate and the cost of each energy type. These data should be adjusted to remove effects caused by production fluctuations or weather. Knowing when electrical peak demands occur is necessary because these determine either the electrical capacity needed or the amount that must be bought. At $500-$800 per kW for construction or $5-$15 per kW per month for purchase, they represent a significant cost. By the time these data are collected, planners should be aware of the importance of energy in the total cost of mine operation, and should have the most crucial time data for electrical peak demand. Flow Process Chart Reducing costs can be accomplished by a thorough look at mine systems and how altering one system causes changes in others. By developing and exercising models of production processes outward to the transportation of the final product, otherwise obscured weaknesses may become apparent. There are tools available for analyzing the mine and its associated systems; one of the most useful is the flow process chart. The flow process chart gives a system analysis of a production procedure by classifying all actions into one of five types: operations, inspections, transportation, delays without paperwork, and delays with paperwork. Operation: In an operation, the nature of something is changed. Examples are blasting, washing coal, and processing matter. Denoted by 0. Inspection: Examining an object for identification or to measure some attribute. Examples are determining whether a drill hole is deep enough, deciding how far to cut under an unsupported roof when operating a continuous miner, or checking the lubricant level on a truck. Denoted bye. Transportation: Moving an object from one place to another. Examples are transporting overburden, moving coal on a conveyor belt, and pumping water. Denoted by =>. Delay without paperwork: A delay that is an inherent part of the system. Examples include idle time of a continuous miner while waiting for shuttle cars or for roof bolting, crushed ore in a storage area waiting for grinding and flotation, and people from one craft waiting for another craft to finish. Denoted by D. Delay with paperwork: A delay that can be terminated only by some written authorization. Examples are coal that cannot be removed until authorized by a bill of sale and transportation orders, personnel records, maintenance, or spare parts. Denoted by V. In practice, the flow process chart is completed after data collection and a detailed examination of the process. Data collection is needed to answer questions on distance, quantity, and time for each of the operations. As the analysis is being performed, each step of the process is subjected to these questions: • Why is the step necessary? • What is being moved? • When does the step take place, and why?

Jan 11, 1983

By I. Nikolic

Twin-roll casting is an integrated casting and rolling process that involves the continuous solidification of a melt and the plastic deformation of the solidified metal between two rotating rolls. Computer modeling is a valuable tool to help engineers understand the metallurgical process during twin-roll casting. However, commercially available software can only model either the fluid flow/heat transfer of the melt or the plastic deformation of the solid, but not both. In this study, an object-oriented finite element program was developed to simulate the steady-state fluid flow, solidification and plastic deformation of an A7,31 magnesium alloy in a horizontal twin-roll caster. The melt, the mush zone and the solid were treated as a generalized Newtonian flow in an Eulerian reference frame and different constitutive equations were employed to describe the material behaviours. The effect of operational parameters on the solidification process was discussed based on the simulation results.

Jan 1, 2010

By Pooley F. D

The coal measures of the South Wales coalfield contain at least 50 horizons at which coal seams are known, to occur. More than 300 samples of coal were collected from these coal measures and this paper outlines thefindings of an investigation of the pattern and distribution of 12 trace elements in South Wales coals. A comparison of trace element contents of the South Wales coals is made with trace element values found elsewhereand an attempt was made to establish the organic affinity of the elements in different seams and in the coalfield 'as a whole. An important function of such an analysis is to determine the order of abundance of trace elements and this was performed for individual seams and for the whole coalfield.The interrelationship of certain elements in some seams is also examined with a view to understanding the effectiveness of such an approach to seam correlation.Ranges of values are quoted together with the mean values of the various elements. Variations of elemental values within a seam section and over the coalfield as a whole are discussed.

Jan 1, 1977