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By Sun Shao Xian

The Port of Shekou is situated at Shenzhen Bay on the east side of the Pearl River estuary. Geological condition of the site is quite complicated. On top of the sea bed, there is a layer of soft silt 8 - 14 m thick. Under the soft silt, there are intercalated layers of sand, silt and clay. Average surface elevation of the underlying undulatory weathered bed rock is about - 20 m, with a variation of about 10 m. In certain locations, the weathered bed rock is covered with a layer of silt 3 - 4 m thick. This paper gives brief account of three types of wharf structures which are of particular interest, constructed in the last few years: (A) Platform type wharf structure with frontal sheet piling and steel raking pile in the rear; (B) Relieving Platform type structure with steel sheet piling and inclined anchoring HP pile ; (C) Steel pipe pile row supported apron added to a marginal quay. Average construction time of a deepwater berth is about six months.

Jan 1, 1991

By Jacob Carr, Chenming Zhou, Nicholas Damiano, James Noll, Jingcheng Li

Machine-related injuries are one of the major safety concerns in underground coal mines. Severe injuries and fatalities occur when a miner is struck, crushed, or pinned by mining equipment such as a continuous mining machine (CMM), shuttle car, or a scoop. Proximity detection systems (PDSs) have been applied in mining to reduce these types of injuries and fatalities. All of the PDSs that are currently approved by the Mine Safety and Health Administration (MSHA) for use in underground coal mines are magnetic-field based and could be affected by metallic objects such as trailing cables. Researchers from the National Institute for Occupational Safety and Health (NIOSH) investigated the influence of trailing cables on the performance of PDSs. In particular, the magnetic field coupled from proximity system generators to a de-energized trailing cable was characterized. The results show that significant energy can be coupled from the proximity system generators to a trailing cable when there is a closed loop in the cable. The effect on PDS performance from the magnetic field radiated around an energized trailing cable was also quantified for different current amplitudes in the cable. It is shown that the magnetic field caused by the electric current in the trailing cable mainly consists of a 60-Hz signal and its harmonics which causes little interference to the PDS. The results presented in this paper can help PDS manufacturers to design better systems that are more immune to these effects.

By Almer E. C. van der Stoel

"Abstract This paper deals with assessing the bearing capacity of existing wood pile foundations. With a wide range of restoration projects being performed in the Netherlands, on many locations deep excavations need to be constructed next to existing, many times listed buildings. The building are founded on piles that are often centuries old, so a close evaluation of the remaining bearing capacity, combined with and assessment of the influence of the excavation is in place.After giving an introduction on Dutch pile foundations, a methodology is described to assess the bearing capacity. Aspects as physical foundation investigation, determination of the current bearing capacity and a calculation of the bearing capacity in the new situation are discussed. The results of both analytical and Plaxis calculations are outlined, focussing on how to practically use this approach in renovation projects. Finally, cases studies of the successful application of this approach in major renovation projects in Amsterdam, such as the Conservatorium Hotel and the New Rijksmuseum are used to illustrate the successful application of this approach.A Short Dutch Pile Foundation History (based on Van der Stoel, 2001)The first houses built in Amsterdam, in the 12th century, were very light constructions of timber without foundations. Because of the soft peat layers found in Amsterdam, the houses there suffered from damage due to settlement. In the 13th century, castles and churches were increasingly built of bricks, which made it necessary to provide support for bigger loads. Under the wall of the construction a trench was dug, and this was filled on either side by alder fascines. Between the fascines small wood piles were driven (by hand) on which another series of fascines was put. On top of this construction, were placed oak slabs on which the bricks were then laid. From that moment on, a problem was caused by the decay of wood foundation elements in the humid soil. In 1503 a law was introduced forbidding building foundations on public streets without permission of the Building Inspection (to keep the fronts of the buildings in a straight line). In 1528 a law requiring permission from the local authorities for all building activities replaced this law. In this period developments started which led to the use of the type of foundation that can be considered the mother of the current “typical” Dutch pile foundation. The piles used in this period were shaft- bearing piles about 5 to 7 meters long. The mostly pine piles were driven between oak beams, which were placed on either sides of a trench, after which other oak beams were laid across at regular spaces: the so called “pile bent” pile foundation (Figure 1)."

Jan 1, 2014

By Claude Bazin, Jalna Lamontagne

"The operators of mineral processing plants collect daily samples from strategic process streams with a view to prepare production balances to assess plant performances. The rules to minimize the risk of systematic sampling errors are known and applied in many mineral processing plants. The mass of the sample to be collected is calculated to yield a target measurement reproducibility considering the fundamental error associated to the sampling of heterogeneous material. This paper demonstrates that this practice is partly valid if one does not account for the time variation of the ore composition during the day. The concept is demonstrated using samples collected on a 30 minute basis from different streams of a gold ore concentrator. Results show that depending of the natural variability of the stream characteristics the mass of the daily samples may not be the critical variable to obtain reproducible measurements. On the other hand the number of cuts taken during the day could impact on the variance of the measurements obtained from daily samples.IntroductionMineral processing plants may treat several thousand tons of ore every day to produce concentrate or impure gold ingots. The operation and performances of these plants are monitored on a daily basis through the collection of ore samples from various streams of the processing circuit. The samples are prepared and assayed to obtain the concentrations of target elements that are subsequently used to calculate the mass flowrates in the streams of the circuit and ultimately the distribution of the target metals for the estimation of the plant performances (Morrison, 2009; Lachance and Leroux, 2016).The acquisition of representative and reproducible samples is therefore the first step in the characterization of plant performances. The term representative sample is used here to indicate an unbiased sample, i.e. a sampling procedure that does not introduce a systematic error. Rules for the collection of unbiased samples are reviewed in the literature by different authors (e.g. Morrison, 2009) and are not discussed in this paper. The term reproducible indicates the dispersion of the measurements around the average value of a characteristic of a stream meets an acceptable level of variance. The reproducibility of a measurement process (sampling and analysis) is assessed by the relative standard deviation or coefficient of variation of the measurement that is a function of the sampling and assaying errors (Morrison. 2009; Gy, 1979). Usually the focus is put on the fundamental error of sampling whose variance can be controlled by the choice of the primary sample mass or adequate particle size reduction during the preparation of secondary or tertiary samples extracted for the chemical analysis. When a sample is taken from a stream that exhibits a time varying characteristic, the obtained measurement exhibits a variability that is not only a function of the sample mass but also of the natural variability of the ore in the sampled stream. This paper examines this aspect of the sampling of a time varying process on the reproducibility of composite samples for a day of production."

Jan 1, 2017

The information in this document has been prepared as at February 16, 2011. Certain statements contained in this document constitute ?forward-looking statements? within the meaning of the United States Private Securities Litigation Reform Act of 1995 and forward looking information under the provisions of Canadian provincial securities laws. When used in this document, the words ?anticipate?, ?expect?, ?estimate?, ?forecast?, ?will?, ?planned?, and similar expressions are intended to identify forward-looking statements or information. Such statements include without limitation: statements regarding timing and amounts of capital expenditures and other assumptions; estimates of future reserves, resources, mineral production, optimization efforts and sales; estimates of mine life; estimates of future internal rates of return, mining costs, cash costs, minesite costs and other expenses; estimates of future capital expenditures and other cash needs, and expectations as to the funding thereof; statements and information as to the projected development of certain ore deposits, including estimates of exploration, development and production and other capital costs, and estimates of the timing of such exploration, development and production or decisions with respect to such exploration, development and production; estimates of reserves and resources, and statements and information regarding anticipated future exploration; the anticipated timing of events with respect to the Company's minesites and statements and information regarding the sufficiency of the Company's cash resources. Such statements and information reflect the Company's views as at the date of this document and are subject to certain risks, uncertainties and assumptions, and undue reliance should not be placed on such statements and information. Many factors, known and unknown could cause the actual results to be materially different from those expressed or implied by such forward looking statements and information. Such risks include, but are not limited to: the volatility of prices of gold and other metals; uncertainty of mineral reserves, mineral resources, mineral grades and mineral recovery estimates; uncertainty of future production, capital expenditures, and other costs; currency fluctuations; financing of additional capital requirements; cost of exploration and development programs; mining risks; community protests; risks associated with foreign operations; governmental and environmental regulation; the volatility of the Company's stock price; and risks associated with the Company's byproduct metal derivative strategies. For a more detailed discussion of such risks and other factors that may affect the Company?s ability to achieve the expectations set forth in the forwardlooking statements contained in this document, see the Company's Annual Report on Form 20-F for the year ended December 31, 2009, as well as the Company's other filings with the Canadian Securities Administrators and the U.S. Securities and Exchange Commission. The Company does not intend, and does not assume any obligation, to update these forward-looking statements and information. Marc Legault, a Qualified Person and the Company?s Vice-President, Project Development, reviewed the technical information disclosed herein. For a detailed breakdown of the Company?s reserve and resource position see the February 16, 2011 press release on the Company?s website. That press release also lists the Qualified Persons for each project.

May 1, 2011

By J. A. Elliot

Deep Mix-in-Place soil stabilisation is achieved by forming columns of soil/cement arranged to overlap by secant intersection. Alternate columns are constructed initially and infilled. The cementitious material injected is designed to retard the strength of the resulting mix thereby allowing satisfactory overlapping. Columns are constructed using a designed large diameter mixing auger mounted on a smaller diameter auger stem. This is firstly screwed to the design depth removing only such spoil as to enable penetration of the auger, and subsequently counter rotated and extracted in a predetermined mixing pattern and grout injection rate to ensure continuous and homogeneous treatment through each successive level. The process is performed whilst monitoring auger depth, grout flow and pressure. Cementation Piling and Foundations Limited used this technique to stabilise allu­vium and to facilitate the construction, by conventional techniques, of a circular pumping station pit of 10M diameter to 10M below ground level. The work was carried out within 3M of adjacent domestic properties, and on a very restricted site in Elland, West Yorkshire. Ground conditions consist of 2M of cohesive alluvium becoming water bearing and increasingly sandy and gravelly with cobbles which overlies the mudstones at 10.0m depth. Sandstones beneath formed an aquiclude to artesian ground water with the underside of the open excavation approxi­mately 1.0M from the top of this material. Peripheral treatment into the mudstone, coupled with pressure relief wells, proved successful and final excavation depth was achieved in "the dry".

Jan 1, 1989

By J. Reed

The RockWorks EarthApps represent a free collection of 74 geology-related programs that read data from a built-in datasheet and create diagrams within Google Earth. EarthApps also includes programs that extract data from Google Earth. The programs that create diagrams include: point mapping (e.g. borehole locations), proportionally scaled icons (e.g. geochemistry), and strike & dip symbols. Line mapping utilities include; polylines, parabolas and pipelines. Polygon mapping programs include; thematic mapping (e.g. geology), mining claims, and public land survey sections. Image overlay capabilities include; draping (e.g. geologic maps) and time-based animations. Vertical image display capabilities are centered on either midpoints (e.g. drill-hole logs) or stretched between endpoints (e.g. cross-sections). The Flyover programs create virtual tours for site presentations. The cell-mapping includes a variety of algorithms (e.g. geochemical and geophysical contouring). Survey programs convert and export survey data to Google Earth as points and polygons. Programs that extract data from Google Earth include; points, lineations, polylines, and polygons. The RockWorks/EarthApps collection is developed by RockWare Incorporated based in Golden, Colorado.

Feb 27, 2013

In spite of a global economy that continues to seesaw and a U.S. Congress that is at odds with the president and themselves, cities around the world are still spending billions on their infrastructure. And that bodes well for the underground construction and tunneling industry and the professionals who work in it. In June, 1,405 of those professionals gathered in San Francisco, CA for the Rapid Excavation and Tunneling Conference (RETC). In addition to the first rate technical programming, attendees were able to see first-hand the latest in tunneling technology from 127 exhibitors who occupied 152 booths. Two short courses preceded the conference and two field trips were offered following the conference.

Jan 1, 2011

By Robert M. Valentine, Randall L. Lentell

Interpretive geotechnical investigations were performed for the construction of approximately 15,250 m (50,000 ft) of wastewater interceptor tunnels in Austin, Texas. Subsurface materials consist of claystone (or clay shale), siltstone, altered volcanic tuffs, chalk and limestone. Special conditions include multiple crossings of Onion Creek with cover ranging from about 1/2 to 3 m (2 to 10 ft.), and the potential for mixed-face conditions consisting of water-bearing gravels overlying clay shale or siltstone. The methods and results of the geotechnical investigations are discussed and the inferred construction conditions are compared to those encountered during tunneling. A suggested format is presented for interpretive geotechnical reports for underground construction projects.

Jan 1, 1985

By F. A. Seward

A1though the expanding Eltran1 configuration has been used in induced polarization exploration for several years, there has been little application of this method to straight resistivity problems. A comparison of results of resistivity exploration by this technique versus those obtained from Wenner configuration surveys reveals a number of advantages in interpretative resolution as well as in field operation. The application of electrical resistivity to ground-water exploration is well known.= In the past a major portion of this work has been accomplished by use of one or more variations of a technique employing the Wenner3 electrode configuration. With the introduction of the frequency domain technique of induced polarization measurements, used primarily in the exploration for disseminated sulfide deposits, there arose the need for an electrode configuration by which potentials could be measured externally to the current electrode spread in order to minimize coupling between current sending and potential receiving circuits. It was also deemed desirable that the configuration would provide information laterally along profile as well as with depth. To reach these objectives the expanding dipole-dipole configuration (which probably first was used in the electrical transient method of exploration and from which the name 'Eltran' was derived) has been adapted to induced polarization exploration. The author has successfully applied the same techniques

Jan 1, 1963

By Bruce Cavender

Historically, the processing function has been regarded as efficiently managed as long as production costs were kept low, recovery was adequate and sufficient plant capacity was avail-able. In this paradigm, processing is viewed as capable of making only a limited contribution to a company?s competitive advantage. However, the processing function can provide a primary vehicle for building critical competitive capabilities. Processing organizations should be encouraged to become so accomplished they generate new opportunities for other functional groups and thereby influence a company?s overall strategy. This requires a deep shift in processing?s role, in its self-image and in the expectations of it held by managers in other functions. Specific plant improvement techniques ? total productive maintenance (TPM), loss control, etc. ? should be viewed primarily as means for building strategically valuable processing capabilities. Different improvement strategies create different kinds of capabilities and present new strategic options. Broadly speaking, a mineral-producing company seeks competitive advantage through two principal activities: the development of new mineral production and reserves and the optimization of existing operations. These lead to increases in ore reserves, production levels and cash flows that are manifested in increased profitability and, hopefully, increases in the price of the firm?s stock. The profitability of a minerals company is a function of the overall profitability of the industry sector in which the company participates and the firm?s competitive position within that sector relative to those of its competitors. Competitive advantage within the industry comes from two sources: the ability to maintain lower prices than competitors for the same product (cost leadership), or from the sale of products with unique properties that justify higher prices (product differentiation; Porter, 1980). Most mineral companies produce fungible commodities that are sold to anonymous customers, and sustainable cost advantage is the only long-run strategy available to these companies to enhance profitability.

Jan 1, 2008

By J. A. Hayes

For over a decade the Osterberg Load Cell has been successfully used to determine the shear capacities of drilled shafts. Since the test method measures side shear directly, analytical complications due to the influence of end bearing resistance are removed. The data suggest that the side shear component of a drilled shaft's capacity is often more significant than end bearing. Given the interest in the use of side shear in drilled shaft design in compressible materials, it is important to examine factors that can influence capacity. We have found that some factors widely believed to influence capacity, such as slurry type, are not as important as commonly thought in most materials. Factors that are not usually considered as important, such as casing use, hoop spacing, concrete slump, concrete additives, spacers and rebar clear cover, seem to be more influential with respect to side shear capacity. For example, substantially lower than predicted shear resistance can occur when the rebar clear cover is small with respect to the cage diameter. We observe this most often in fine-grained cohesive soils. This effect can be exaggerated if the rebar cage has tight hoop spacing, if the concrete has low slump and if the hole is not straight. We have also noted that improper use of temporary casing can have a dramatic effect on side shear resistance. In some cases we have observed tested shear capacities reduced to less than 5% of either predicted or available shear values.

Jan 1, 2003

By Miller F. S

The famous Golden Mile of Kalgoorlie in Western Australia was, between 1888 and 19ft, one of the richest and most important gold camps in the world. Annual production, which reached a peak of nearly 1,300,000 oz. in 1903, however dropped to below 400,000 oz. after 1920.Depression seized the camp, and many mines closed down. The output from this old field is now steadily mounting under the stimulus. of a higher price for gold. In 1935 300,000 oz. of precious metal were recovered and the future is bright. Total production from the field is 21,400,000 oz., whereas something like £23,600,000 have been paid in dividends.The Golden Mile has been studied by many geologists. Their somewhat diverse findings were published for the most part in the Australian technical press which, unfortunately, is not sufficiently represented in foreign libraries.The following article is based on an eighteen months' study in the district for Gold Mines of Kalgoorlie Ltd., preceded by four years' experience with almost identical rock types in the, Porcupine district of Ontario. The excellent record of observed fact left by previous invesigators, augmented by talks with observant mining men...

Jan 1, 1937

By Z. T. Bieniawski, José Miguel Galera, Benjamín Celada

TBM case histories from over 400 tunnel sections are analyzed presenting a comprehensive application of the Rock Mass Excavability (RME) index (Bieniawski et al.2006). The paper introduces two new adjustment factors, called the Factor of Tunnel Length and the Factor of Crew Effectiveness, which were established to represent more realistically the interaction of the rock mass characteristics, the TBM parameters and the performance of the crew operating the machine. A new correlation is provided for predicting the average rate of advance of double-shield TBMs working specifically in the double-shield mode.

Jan 1, 2007

By Dean Brox

The Galore Creek Mine project is one of the newest major mining projects under development in Canada. The project is located in a very remote area of northwestern British Columbia and is being developed by NovaGold Resources and Teck-Cominco of Vancouver. The mine project comprises one of the largest and highest grade undeveloped porphyry-related gold-silver-copper deposits in North America. In order to access the mine site a new 120 km road is required including a 4.4 km mine access road tunnel. Glaciers with heavy snow pack cover approximately two-thirds of the tunnel alignment with a maximum cover of 1200 m. The size of the access road tunnel is about 50 m2 and has been designed as a large single lane road tunnel to accommodate the transport of large size mining equipment for mine start up and ongoing operations. The rock conditions along the tunnel alignment comprise very strong volcanic rocks. Key services for mining operations will be incorporated into the tunnel comprising diesel and power as well as the concentrate pipe-line. Structural portal canopies and portal houses have been incorporated into the tunnel design due to the risk of rockfalls and avalanches in the portal areas. The mine access road tunnel is a significant and critical-path component to the overall project to provide vehicular access to allow construction of the mine site. In order to meet the expected mine start up date the construction of the tunnel works have commenced prior to any other works at the mine site and will be constructed entirely by helicopter support. The tunnel works commenced in the summer of 2006 with the advanced excavation of the overburden materials at the portals. Tunnel construction from the North portal commenced in the spring of 2007. When completed, the mine access tunnel will be the longest private road tunnel in North America. The key design and constructability issues for the mine access road tunnel project are presented and discussed along with a construction status update as of late 2007.

Jan 1, 2008

By Brian Fulcher

In April 1997, Kiewit/Parsons Brinckerhoff (K/PB) completed the 7,600-m (25,000-ft) primary access tunnel for the Yucca Mountain, NV proposed high-level nuclear waste site. K/PB then began boring an exploratory east-west cross drift tunnel at the site. The 2,681-m (8,796-linear ft)East-West Cross Drift Tunnel was excavated through volcanic tuffs having zones of incompetent rock using a rebuilt Robbins 5-m (16.4-ft)hard-rock tunnel boring machine(TBM) with a special arrangement of supporting equipment. This portion of the Yucca Mountain project was completed in eight months.

Jan 1, 2000

By Andy Schroeder

Located in Hamilton, Ontario Canada, Berminghammer Foundation Equipment, is a manufacturer of advanced foundation equipment with 30 years of experience. The company is represented in more than 20 countries world wide, maintains an extensive Research and Development team, and has earned a reputation for finding the most practical solutions to the most challenging projects. The vertical travel lead, referred to as "VTL" system, was first developed and patented by C.W. Bermingham in the 1970's. This lead system was developed in response to the fundamental limitations of either a fixed lead or hanging lead system. The fixed lead system is well suited to level job sites with few obstructions and has the advantage of faster positioning of the lead, the hanging lead is very adaptable to different elevations and batter piles but takes much longer to position. Therefore the Vertical Travel Lead was developed to combine the advantages of fixed leads, fast and accurate positioning, with the ability to adjust the height of the lead base up or down. The VTL lead is connected to the boom by a sliding connection which allows the lead to be elevated or lowered below grade. The advantages of the VTL system were recognized by many foundation specialists and they have become the Industry standard in Canada , US Railway Construction , and many parts of the USA.

Jan 1, 1997

By R. G. Burn

"A brief outline will be given of the concept of risk and its implications with regard to investment in exploration. The relationship between risk and decisions under uncertainty will be examined as a prelude to identifying those factors which contribute to exploration risks:consideration of the effects of corporate objectives (e.g. survival, expansion, diversification) on exploration strategy and ultimately on success or failure, exploration and mining as an investment (the relationship between risk and reward) and the desired return on investment; exploration odds, funding levels, staying power, financial exposure and the concept of gambler's ruin;origins of uncertainty in exploration decision-making-man-made risks and natural hazards; the nature of introduced constraints at each exploration decision stage and their effect on the rate of success;improving the chances of success and the invest reduction of risk through sound exploration strategy, effective project generation and efficient target detection capabilities."

Jan 1, 1984

By S. Rivard

"This paper demonstrates the selection of grinding circuit technology for a number of recent projects including discussion of the key drivers and the role of energy efficiency. Decreasing head grades combined with a strong and sustained increase in operating costs has forced miners to examine increased project size, increased equipment capacity and efficiency improvements in order to reduce their unit operating costs and improve overall project economics. Comminution energy consumption, safety and capital cost considerations play a critical role in the success of projects. This paper presents some key guidelines for a successful and cost effective comminution circuit design and includes a case study on three projects, outlining the issues and the drivers which led to the ultimate circuit selection and the critical role that energy efficiency played.IntroductionComminution circuits for minerals processing are selected based on their suitability and efficiency in reducing run-of-mine ore to the desired feed size for the downstream process. The input material (ore) properties and downstream process requirements are the key determinants and there are standard approaches for each circumstance.The minerals processing industry has been a fast adaptor of efficiency improvements based on increasing capacity of equipment (e.g. trucks, crushers, mills, pumps) but less successful in adapting radically new technologies that disrupt incumbent flowsheets or processes.The installed power of grinding mills has increased linearly over the past 25 years (Meka & Lane, 2010) and pumps and classification equipment have kept pace. The autogenous grinding (AG) and semi- autogenous grinding (SAG) mills displaced stage crushing as a dominant method of coarse rock breakage in many applications causing crusher manufactures to increase the capacity of cone crushers to meet the competitive demand.Examples of new comminution technology in the 20th and 21st centuries are the development and adoption of cyclone classification in the 1940s (Newtech, 2016), AG milling in the late 1950s, vertical grinding mills in the 1980s, high pressure grinding rolls (HPGRs) also in the 1980s and ultrafine milling technology in the 1990s (Meka & Lane, 2010)."

Jan 1, 2017

By J. H. East, D. Harrington

"INTRODUCTION Considerable interest has been shown in the prospective use of Diesel-powered haulage equipment in both coal and non-coal mines. Foreign technical magazines have devoted considerable space to discussions of the use of Diesel locomotives in European mines and some mention of it has been made in technical papers in the United States. The Bureau of Mines has extensively tested the gases produced in the exhaust of the Diesel engine under various atmospheres and conditions of use; it has established a schedule of tests for permissibility of Diesel engines for use in underground coal mines, including, gassy or dusty mines.This publication provides information as to the successful use of Diesel-powered equipment underground workings in the United States and Europe, briefly discusses the characteristics of some of the toxic gases found in the exhaust of Diesel engines, and points out that Diesel-powered equipment can be used with reasonable safety in underground minus if necessary and entirely feasible precautions are taken."

Apr 1, 1947