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By Jozef F. Zurawski

Increasingly new interceptors or new Combined Sewer Overflow (CSO) projects require connections to existing tunnels. More often than not, the existing facilities are old, in poor or questionable conditions, without proper construction records or as-built drawings. Many cannot be easily inspected unless major construction effort provides flow by-pass for safe access. This paper provides general guidelines on how to approach the problem of assessing the condition of old tunnels, how to plan and design the connection with limited physical assessment, how to develop the scope of work for the bid documents and how to provide geotechnical guidelines and designs for the bid documents.

Jan 1, 2008

By Oliver Zach

To know as much as possible about the condition of the refractory material (lining thickness, slag layer, build ups, ...) in an high temperature furnace is very important due to the safety and economic impacts. The new CONSCAN system offers the possibility to measure the inner surface of an furnace, and based on this results to calculate the thickness of the refractory lining, slag layer, build ups,.... The CONSCAN System provides this results as figures and graphics. This system is also working under hot conditions so it is not necessary to cool down the furnace. Based on these results the process control and the refractory lining concept could be optimized for maximum campaign life of the furnace.

Jan 1, 2006

A tectonic interpretation of the Coromandel Peninsula which suggests that the basement underwent tensional collapse at its northern and southern ends would permit more ready penetration of late stage magmatic fluids. This hypothesis is consistent with regional trends of the chloride content of low grade geothermal waters and of the yield of gold and silver per unit weight of quartz worked. The consequences of such a model are that mercury should not only be a good pathfinder for Coromandel gold, but that it should be correlative with ratios of base metals high in the zoning or paragenetic sequences to those lower in the sequences. This is demonstrated successfully in an area of mineralisation in the southern Coromandel.

Jan 1, 1987

By R. M. Corn

The Non-Time Critical Forest service CERCLA Action at Mansfield Canyon, Santa Cruz County, Arizona designated previous locators of unpatented mining claims as owners/operators of the Hazardous Waste Facility, retroactively liable for all reclamation costs including reclamation of mines acquired by the Forest Service. The CERCLA Action is based on non-existent tailings, a non-existent permanent resident, inaccurate and unreliable data and did not review or consider prior USGS and USBM data. The consequences of the Forest Service action include(1) reduced exploration, (2) loss of credibility, (3)public disillusionment and distrust.

Jan 1, 2000

By Erika Calmell del Solar, Germán Chávez

Desde el 2012, en el área de influencia de la Unidad Minera Constancia ubicada en Chumbivilcas, Cusco, Hudbay Perú S.A.C. (Hudbay) junto con el Centro de Ornitología y Biodiversidad (CORBIDI) han desarrollado el Programa de Rescate y Reubicación de dos especies consideradas sensibles a las actividades del Proyecto Constancia: Una rana en estado vulnerable (Telmatobius marmoratus) y una lagartija endémica (Liolaemus annectens). El programa para ambas especies consistió en 5 fases: Búsqueda y rescate, Crianza en cautiverio, Marcaje, Liberación, Monitoreo y recapturas de las poblaciones liberadas.

Sep 1, 2017

By George R. Elliott

Introduction The pages that follow present a brief chronological survey of views which have been held, and of legislation enacted, for the regulation of the natural gas and oil industry in the Turner Valley field, especially as regards conservation of the natural gas. To provide a necessary background for an adequate understanding of the progress of events in western Canada, there is included also a compilation, from technical and legal authorities, of some of the more important measures which have been adopted for the regulation of the oil and gas fields of the United States, where these measures have had, or are likely to have, a bearing on the course of our domestic industry. Owing to exigencies of space, it has been possible to refer only to the most outstanding proposals and legislation, and to these in the briefest possible form. Although, so far as Canada is concerned, the data presented are restricted almost entirely to the Turner Valley field, it is the hope of the writer that the paper may prove of value for purposes of reference: for any similar gas and oil fields discovered in western Canada will certainly revive and intensify the problem of the proper steps to be taken for the conservation of the gas. Definition of 'Conservation The term conservation has been so misunderstood and misrepresented that, to many persons in Alberta, it means little more than closing-in wells. In the light of the definition of Charles E. Hughes, that 'True conservation of a raw material is its economical use', the subject of natural gas conservation is inseparably involved with the study of the function of the -gas and with the development of the principles of unit operation.

Jan 1, 1934

By James Douglas

IN discussing the waste upon which hinges, or is supposed to hinge, so largely the preservation of our national resources, the conclusions reached would be more reliable if actual ex¬perience were consulted, and fewer deductions were drawn from general statements, which are often the product of the imagination. It cannot be questioned that the value of by-products has not been sufficiently appreciated by us, and that our, tardiness in recovering the useful ingredients of the escaping gas of our coke-ovens is one of the most glaring instances of shortcoming in that direction. And yet even for that sin there is some palliation in the immature condition of affiliated industries. I presume that it is admitted, without argument, that, except under very exceptional conditions, all the elements cannot be recovered from most of the ores or natural products. which we treat. While it is a shame that the by-products from our coke-ovens should be dissipated, Edward W. Parker's report to the U. S. Geological Survey for 1906' supplies a fairly good excuse in justification of this appalling waste. He says (pp. 773 to 774.)

May 1, 1909

Many persons hold the opinion that the metal indus- ries are fortuitous and that the occupation is one of sordid toil, and altogether a kind of business requir- ing not so much skill as labour. But as for myself, when I reflect carefully upon its special points one by one, it appears to be far otherwise. So wrote Georgius Agricola in 1556. He could have been espousing the sentiments of an indus- trial archaeologist investigating mining sites in 1986. South Australia has a very rich legacy from its industrial past-especially in the area of its mining history. Industrial archaeology, which is part of the broad field of archaeology, is concerned with the material and documentary remains of this industrial past. This includes the products and processes of manufacturing, industrial, technolog- ical and engineering activity and their relation- ships to people and the environment. `Archaeology' immediately conjures up the image of excavations in Greece or Eygpt. Excavation however is only a part of archaeological methodology. Industrial archaeology utilizes documentary historical rec- ords combined with field survey techniques (both above and below ground) to create a composite picture of the past. Interest in our recent past has burgeoned in Australia in the last few years. This interest manifests itself in many ways-the unprecedented popularity of Australiana and col- lecting, the plethora of Australian historic films, the growth of the National Trust, local historical societies and genealogical research. Fortunately these trends have been reflected in academic and legislative circles. Various univers- ities, institutes of technology and colleges of advanced education run courses in aspects of cul- tural resource management and conservation of the historic environment. These courses are com- prised of archaeology, architecture, geography, his- tory, materials conservation, museum studies, and national parks management and planning.

Jan 1, 1987

By César Alvarado Olivares

El presente trabajo describe la solución planteada al problema de renovar el equipo de celdas de flotación que por el tiempo de uso (19 años) y por su tipo de diseño, ya no ofrecfa el rendimiento que hoy en día se puede conseguir en esta clase de tratamiento. La solución consiste en

Jan 1, 1963

"El presente trabajo expone las pautas para la realización de un proyecto de fábrica de cemento, como los factores que influyen en su ubicación respecto al centro de distribución y el tipo de combustible que se emplea para la combustión. El impulso a la creación de una fábrica de cemento, se basa en la existencia de depósitos calcáreos, los cuales estratégicamente ubicados, permiten un mayor progreso económico del país y eliminan la limitación del suministro. Para tal fin, es necesario realizar un estudio económico del consumo considerando el período donde el abastecimiento y costo fueron normales. Otro estudio posible estriba en la comparación de la zona prevista de lde la fábrica con otras áreas de características económicas similares, basándose en la población, movimiento económico y otros elementos de comparación. Una vez determinada la zona, se fija el precio de la venta al público a través de tres elementos: precio de venta en fábrica, costo del transporte y la utilidad del distribuidor. Otros estudios a considerar son los basados en los yacimientos, los cuales complementan mejor la información de la instalación. Entre estos, tenemos a los estudios geológicos, levantamiento topográfico, muestreo sistemático, estudio químico de los minerales y pruebas térmicas y físicas de los productos. La ubicación de la fábrica dependerá si se decide instalar en el sitio de la cantera o en el mismo centro de distribución. Como estudio final, se prevee que la materia prima esté constituída por elementos que químicamente y mineralógicamente sean los más idóneos para así recurrir a materiales de complemento cuya dificultad o facilidad para mezclarlos íntimamente, determine el proceso a utilizarse. En consecuencia, la instalación de dicha manufactura, es el resultado del estudio global de las condiciones provistas en un zona, para así constituirse dentro de un mercado económicamente lucrativo. "

Jul 20, 1957

By Jorge Ganoza

Algunos concentrados de plomo contienen contaminantes que afectan la comercialización del concentrado de cobre debido a aspectos ambientales, así como la calidad del producto final. En ese sentido, el presente texto busca la forma de minimizar la presencia del plomo y de bismuto en el concentrado de cobre, a través de la flotaciónpor chalcopirita. De otro lado, dado que el plomo y bismuto son elementos que tienen similar comportamiento durante la flotación, es factible aislar los minerales de plomo y bismuto.

Nov 1, 2012

By N. Nikolaev

La cantidad de métodos experimentales y analíticos no consideran los factores que influyen sobre el proceso de acción recíproca entre los elementos de sostenimiento y el macizo rocoso. En ese sentido, estamos en condiciones de separar dichos factores en grupos, reuniendo en uno los independientes, y en otros los relacionados entre sí. Por ello, el presente texto señala los métodos adecuados para determinar la influencia de un factor determinado o de un grupo de factores sobre el desarrollo del proceso a través de la determinación del tipo de cabeza de anclaje y de la pérdida de tensión final del anclaje con el transcurso del tiempo.

Jan 1, 1973

By Gonzalo Monge Sancho

"El siguiente estudio presenta una serie de observaciones sobre la Organización de Higiene Industrial y su aplicación directa a la medicina del trabajo. La investigación comprende cinco apartados: el primero, es el diagnóstico en la medicina del trabajo, la cual señala la enfermedad, el ambiente y las condiciones vitales como factores claves para de una futura exploración clínica; la segunda, refiere la higiene como la función que mide los medios y los conocimientos para preservar la salud del individuo, en tanto, verifique su trabajo(condiciones ambientales y factores alterables de la misma; el tercero punto contempla los accidentes como la pugna entre un hombre y el objeto, donde el factor médico, las causas (objetivas y subjetivas),el tipo y las condiciones son determinantes para encontrar el problema; el cuarto elemento describe la medicina preventiva como el conjunto de medidas que realizan un diagnóstico precoz de la enfermedad y el tratamiento de la misma, y por último, está el departamento médico donde reduce la posibilidad de enfermedad del trabajador, los gastos de indemnización y aumenta la confianza y seguridad del trabajador, regulando la función del trabajador de acuerdo a sus condiciones fisiológicas para un mejor rendimiento dentro de la mina. "

Jul 20, 1955

By Y. Y. Jiao, J. G. Cai

To investigate the dimensional effect on shock wave propagation in jointed rock masses, a 2-D and a 3-D calculation of a site test are performed respectively by using Discrete Element Method, the simulated results are compared with test data. It shows that, in modelling shock wave propagation and attenuation in jointed rock masses, when the explosive along explosion chamber is long enough and the joints are dense enough or uniformly distributed, the model can be considered as plane-strain problem, 2-D results are good enough to fit with test data. 2-D modelling, with much more details of rock masses taken into account, can be applied to make critical engineering judgements instead of 3-D modelling in some cases.

Jan 1, 2003

By Sathit Tandanand

Geological differences among various coalfields restrain the applicability of subsidence prediction using existing European methods. To modify these methods for domestic conditions, the Bureau of Mines, U.S. Department of the Interior, developed a method of assessment to evaluate the lithological effects on subsidence in the Northern Appalachian basin by examining data collected from 16 longwall panels in the coalfield. The assessment is partially completed, and the results to date show that the ratio of maximum subsidence to the extraction thickness, known as the subsidence factor, can be expressed in terms of the width-to-depth ratio by a simple exponential equation which has a coefficient tentatively considered as the subsidence index. This index varies with the lithology of a particular site and can be expressed in terms of the percent distribution of weak and strong rocks in the overburden.

Jan 1, 1982

By Omkar N. S. Beruar

Extraction of sill pillars has always been problematic because of high risk of seismicity and rockburst. Depending on a number of factors, a sill pillar can undergo different failure modes and cause problems in the mine. Of these, sudden and uncontrolled failure of part(s) of the pillar leading to highenergy seismic events and rockbursts is a main concern because it is not possible to predict the location and time of a rockburst apart from its potential to cause extensive damage to the mine structures. To date, a comprehensive technique for sill pillar design and recovery does not exist. Conventional methods of pillar design, such as the pillar stability graph method, are utilized to design stiff sill pillars. In these design approaches, the post-peak response of the pillar-rock system is not considered. This is in part due to a lack of clear and comprehensive understanding of the post-peak behaviour and failure mechanism of sill pillars. In general, the strength of a rockmass is described using a failure criterion. When stresses reach the strength of the rockmass, the rockmass does not necessarily become unstable and knowledge of the loads alone is not enough to assess the instability conditions accurately. In fact, it is not possible to predict instability of rockmass based on the strength/stress ratio alone because instability depends not only on this ratio but also on the loading condition and loading system characteristics. The loading system can dictate whether the sill pillar will go through a stable or unstable failure process. This paper examines the influence of various parameters such as the pillar width to height ratio, the extraction rate, and placement of backfill on the Loading System Stiffness (LSS) and the Pillar Stiffness (PSS). The ultimate goal is to design yielding sill pillars that would yield in a stable manner and will reduce the risk of pillar rockburst. Plane strain finite element analysis is conducted using the generalized Hoek-Brown failure criterion with elastic-brittle-plastic parameters. Examples are given to demonstrate how to calculate these stiffness values and assess the stability condition of sill pillars. It is found that increasing the rate of extraction increases the likelihood of unstable yielding of the pillar as has been found in other studies. Placement of backfill in a timely fashion in the stopes above and below the sill pillars increases the stiffness of the loading system. This indicates that backfilling of stopes while creating the sill pillar increases the likelihood of stable yielding of the sill pillar.

Aug 1, 2013

By Getu F. Biftu

There is general agreement among scientists that global surface temperatures have been increasing during the past decades. The increase in temperature is postulated to be the result of either an increase in greenhouse gases emission or climate variability (i.e., due to variations in sun or volcanic activity or El Nino and La Nina events) during past decades and may continue to increase. The effects of a predicted rise in the Earth?s surface temperature include an increase in average global evaporation and increase or decrease in precipitation (Bloomfield, 1992; Mann et al., 1991; Vinnikov et al., 1990; Gan 1995; Zhang et al., 2000a). The general circulation models (GCMs) project a global warming due to greenhouse effects of 1.5-4.5°C by the mid 2050s, with the most pronounced changes taking place in northern latitudes (Nicholls et al., 1996). However, similar predictions at a watershed scale or even a regional scale using GCMs are mot possible yet (Arnell et. al., 1996; Georgievskii et. al., 1996; Zhang et al., 2000a). Detection of historic trends, changes and variability in climatic variables is another indirect means of understanding potential future changes or variability at regional and local scales. The main objective of this paper is to review studies related to climatic change or variability and associated hydrologic changes at a regional scale and local scale, particularly those studies applicable to the Oil Sands Region (OSR) of Alberta. This paper identifies gaps in our current understanding of the hydrologic processes that may be affected by climate change; it discusses potential implications to developments in the OSR; and it explores mitigation opportunities including several that have already been implemented.

May 1, 2004

By Kazunori Matsushita, Masaru Sakakibara, Kenji Harada, Naotoshi Shinkawa, Mitsuo Nozu

The Sand Compaction Pile (SCP) method has been widely used as a typical countermeasure against liquefaction in Japan, and its effectiveness has been confirmed in many case histories of damages caused by the past large-scale earthquakes. A series of studies were conducted to evaluate the effectiveness of the compaction method and other factors, if any, in sustaining a seismic force that is greater than the assumed one and caused no damage. Based on the results of these studies, the Architectural Institute of Japan (AIJ) has indicated in its “Recommendations for Design of Ground Improvement for Building Foundations” published in 2006 that the liquefaction resistance ratio (tl/sz) of the composite ground, which consists of sand piles and surrounding compacted ground, is higher than the RL calculated by using the SPT N-values of the ground in-between the sand piles. In this paper, statistical analysis of safety factor against liquefaction, FL, was performed by using the SPT N-values of ground in Port Island and Rokko Island which were both fully reclaimed islands in Kobe city during the 1995 Hyogo-ken Nambu Earthquake (classified as intense shaking) and, together with the consideration of relative settlement, resulted in tl/sz of the composite ground being 1.5~2.5 times of tl/sz of the soil in-between piles after improvement. Furthermore, the liquefaction resistance curve of SCP-improved sites obtained from the relationship between SPT N-values and cyclic shear stress ratio during the 2011 off the Pacific Coast of Tohoku Earthquake, which was regarded as long-duration earthquake, was plotted to the left side of the curve originally proposed by Japan Road Association. Thus, the liquefaction resistance of the improved ground was found to be higher than that of the natural ground, even for the same SPT N-values, verifying the validity of the AIJ recommendation.

Jan 1, 2017

By A G. Noble

Tunnelling for hydro-electric power projects can be a very challenging component of the overall development. In contrast to urban transportation tunnelling where the logistics for access and supply of power, water and other essentials are readily available, hydropower projects are usually in very remote locations and all necessary plant, equipment, spares and materials need to be brought in and the site must function as a self sufficient unit.For a large scheme the river diversion tunnel(s) are usually on the initial phase critical path in order to meet the non-negotiable deadline of river diversion before the onset of the wet season. A newly formed tunnelling crew, once mobilised to the site for the project, will face the first major learning curve of the project’s systems and logistics during this critical tunnelling activity.Power tunnels convey the water to the turbines in the powerhouse and are usually on the critical path for the main works, especially if the scheme comprises a powerhouse located within an underground cavern. A modern cavern arrangement requires a complex warren of various openings: access adits, ventilation/cable tunnels, shafts, surge tunnels, etc.Hydropower tunnel construction tends to be dominated by tunnel boring machine (TBMs) or drill-and-blast excavation techniques and each has its challenges in very remote locations. TBMs still have long lead times as for any type of project, but additionally require a thorough roads and bridges infrastructure assessment of the country from the port of entry to the site to ensure a problem-free delivery. In some cases the project also requires the establishment of a complete precast concrete segment production facility and the space for creation of laydown areas; there is no ‘just-in-time’ delivery mechanism applicable to typical remote hydropower sites.This paper highlights the technical and risk management considerations in the planning, design and construction of tunnels for hydropower projects. It contrasts the typical factors that govern the design of urban transportation tunnels with those for remote hydropower tunnels. The perspectives of stakeholders are provided including those of international lenders. With examples from large and small scale projects across the globe it provides an insight to all parties and in particular, those tunnellers that are working in the hydropower field for the first time.

Mar 8, 2011

By Steven W. Hunt, Isabelle Lamb, Steven B. Fradkin

Groundwater control is generally an important consideration and significant source of risk during most tunneling projects. Proper baselining of groundwater conditions requires: 1) a thorough understanding of the geological environment; 2) a focused site investigation; 3) identification of construction and adjacent property damage risks associated with inflows and short and long term piezometric level changes; and 4) consideration of contractual issues including restrictions on means and methods and pay items for associated work. This paper provides an overview of groundwater baselining issues and risks based on selected design studies and construction case histories.

Jan 1, 2005