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By Charles Dumaresq

The management of mine tailings poses a complex range of potential risks, including physical risks, such as the risk of catastrophic failure of a tailings facility and chemical risks such as the risk of long-term leaching of contaminants into the downstream environment. If these risks materialize, they can lead to a wide range of impacts on people and the environment, including human fatalities and severe impacts on downstream ecosystems, and the costs of recovery borne by industry, communities, governments, and society as a whole can be immense. Tailings facility failures in Canada (2014), Brazil (2015 and 2019), South Africa (2022), and in other locations around the world underscore how high the stakes are when mines produce and manage tailings (WISE Uranium Project 2019). Understandably, many people do not trust the mining industry to manage tailings responsibly. As an industry, it is our responsibility to manage tailings in a manner that is responsible and strives to minimize harm associated with tailings management, including effectively managing both the physical and chemical risks associated with tailings. Standards have an important role to play in responsible tailings management by setting expectations for standards of care and providing a means to measure and report on performance. In jurisdictions with strong legal requirements for tailings management, standards play a complementary role, pushing performance improvements in areas that may be difficult or impossible to address in legal requirements. In jurisdictions where legal requirements are lagging, standards may represent the de facto leading practice and may be the primary tool to help ensure responsible tailings management. Implementation of standards can help companies demonstrate that tailings are being responsibly managed and help build trust and credibility. Most importantly though, standards are important tools to help ensure that the risks associated with tailings are reduced, and that remaining risks are effectively managed. However, we must recognize that conformance with standards can have a down-side – the proverbial two-edged sword. Having standards is vital but there is a risk that implementing standards becomes a “box checking” exercise, with ongoing conformance leading to complacency. We must not allow ourselves to fall into the trap of believing that, just because we are complying with applicable standards and laws, we are therefore doing our best, and that “it can’t happen to us.” In addition, if conformance becomes the goal and the standard does not have mechanisms to drive continual improvement, then once the standard is met, there may be no incentive to improve. The point of complying with standards is not to pass the test. The point is to manage tailings responsibly, prevent catastrophic failures, and minimize harm. The point is to do better, because we must do better. To do that, we need to strive not for conformance, but for excellence in tailings management, driven by continual improvement and a quest to do better.

Feb 1, 2025

By M. C. Bétournay

Strainbursts are common in overstressed brittle rock around deep mine openings. Such failures are characterized by a biaxial state of stress in the plane of the opening boundary. A zone of compressive stresses imposes initial failures near or at the surface of the opening that results in spalling of thin slabs of rock roughly parallel to the free face. While the failure of rock under biaxial loading conditions is increasingly common in deep underground mines, only a few representative laboratory studies have been reported in the literature, without emphasis on rockbursting aspects, and none in the last decade. This paper presents the results of a testing program on a granite rock type. Biaxial testing, conducted on 100 mm cubic samples, was carried out to examine the influence of lateral confinement and loading rate on the rock’s ultimate strength. The paper reports the test results in terms of normalized biaxial failure envelope s1/sc-s2/sc. A discussion of the failure mechanisms observed is presented. Les coups de toits de déformations sont choses communes dans le rock cassant surcontraint en place autour des ouvertures minières profondes. De telles ruptures sont caractérisées par un état de contraintes biaxiales dans le plan de la périphérie de l’ouverture. Une zone de contraintes compressives impose des ruptures initiales à ou près de la surface de l’ouverture, qui produit des relâchements de minces plaques de roc plus ou moins parallel à la surface. Bien que les ruptures de roc sous des conditions biaxiales sont de plus en plus communes dans les mines à grandes profondeurs, il n’y a eu que quelques études représentatives en laboratoire de publiées, sans emphase sur des aspects de coups de terrains, et aucunes publiées depuis la dernière décennie. L’article présente les résultats d’une campagne d’essais appliquée à un type de granit. La campagne d’essais biaxiaux, sur des échantillons cubiques de 100 mm, avait pour objectif d’examiner l’influence du confinement latéral et le taux de chargement sur la résistance ultime du roc. Cet article fait part des résultats en terme de l’enveloppe de rupture biaxiale normalisée s1/sc-s2/sc. Une discussion sur les mécanismes de ruptures observés est présentée. Dehnungsbrüche findet man häufig in übergespannten spröden Felsen um die Öffnung von tiefen Minen. Solche Brüche sind von einer zweiachsigen Spannung in der Ebene der Grenze der Öffnung charakterisiert. Eine Zone von Druckspannungen verursacht initiale Brüche, entweder an der Öberflache der Öffnung oder in der Nähe. Davon scheiden sich dünne Felsplatten mehr oder weniger parallele mit der freien Wand. Obwohl Felsbrüche unter zweiachsiger Beanspruchung immer mehr häufig in tiefen Minen beobachtet sind, hat man über nur einige repräsentative Laborversuche in der Literatur berichtet. Diese Studien diskutieren das Thema ohne Betonung auf Felsbrüchen, und keine sind in den letzten zehn Jahren erschienen. Die vorliegene Arbeit gibt die Ergebnisse eines Testprogramms auf einem Typ von Granitfels. Durch zweiachsige Prüfungen von kubischen Proben mit Seitenlangen von 100 mm sollte man den Einfluss von seitlicher Ermittlung und der Beanspruchungsrate auf die Bruchfestigkeit des Felsen studieren. Man findet auch die Prüfergebnisse in bezug auf das normalisierte, zweiachsige Bruchkriterium s1/sc-s2/sc. Die beobachteten Bruchmechanismen sind auch diskutiert.

Jan 1, 2003

By Andrew J. Petruska, Austin F. Oltmanns

The paper proposes a capacitive load cell for detecting changes in material and tool wear conditions for conical picks used in underground mining. The current process is dangerous and subjective, relying on human operators near the cutting interface. The new sensor aims to improve worker safety by allowing operators to perform their functions from a greater distance.

Aug 1, 2023

By Carl Heinrich

I HAVE read with particular interest that portion of the discussion by Anton Eilers referring to the high-lime (and also high-alumina) slags made by August Raht in 1881, while smelting the Horn Silver ores at Franklin, Utah. The two analyses of such slags, furnished by Mr. Raht to Mr. Eilers are: Horn Silver Slags Oxygen(b) Oxygen(b) Average of I and. II Slag I percentage Slag II percentage Oxygen Si02 33.9 18.1 .35.0 18.7 34.50 18.40 FeO 26.8 6.0 25.4 5.7 26.10 5.80 CaO 26.1 7.5 24.9 7.1 25.50 7.30 BaO 3.2 (a) 0.3 3.2 0.3 3.20 0.30 A1203 10.8 5.1 9.3 4.4. 10.05 4.75 100.8 37.0 97.8 36.2

Jan 10, 1916

By A. N. Baldwin

This report documents work performed under Bureau of Mines Contract J0265029 to study and develop two innovative mining systems: ? An underground auger capable of augering into the right and left ribs without repositioning the machine ? A conventional mining system employing recently developed innovative machinery. The report is separated into two volumes to document the two studies separately. Volume I describes work performed and the recommended concept for a bidirectional auger. Volume II describes the studies of mining equipment performance and mining plane developed to determine a conventional mining plan offering improved productivity.

Jan 1, 1977

By Mohsen Mohammadi, Edward Cyr

"To date, several studies have been performed on the static mechanical properties of SLM-AlSi10Mg alloy. There have also been more recent studies on the relation between scan strategy, texture, and mechanical properties of SLM metals and composites. However, there is a huge knowledge gap in the available literature regarding texture and mechanical behavior of SLM-AlSi10Mg alloy under high strain rates. Therefore, in this study, dynamic mechanical behavior of AlSi10Mg_200C alloy manufactured by DMLS technique was investigated at high strain rates ranging from 900/s to 1700/s using Split Hopkinson Pressure Bar. Texture using X-ray diffraction technique of the initial samples were measured. The yield strength, peak flow stress, and ductility increased in all samples with increase of strain rate. TEM studies have also revealed evidence of continuous dynamic recrystallization in grains after 900/s–1700/s strain-rate tests. A Taylor polycrystal crystal plasticity constitutive model was then developed to capture and predict the texture evolution and mechanical response under dynamic loading, using plastic work as a critical parameter for the onset of recrystallization.INTRODUCTION Additive manufacturing (AM) powder techniques are among the fastest advancing breakthroughs in manufacturing in recent years, defined by a bottom-up layer by layer process of joining with energy input from lasers or electron beam (Herzog et al., 2016; Gibson et al., 2015). Among alloys fabricated by SLM, AlSi10Mg is of high interest to industry and academia due to its low density, high specific strength and excellent corrosion resistance, making this alloy a viable contender for aerospace, automotive, and marine applications. Circumstances such as car crash or bird aircraft strike hazards subject potential additively manufactured AlSi10Mg parts to impact loadings. This drives an interest in understanding and predicting dynamic behaviour of these alloys. AlSi10Mg is the AM counterpart of A360 die-cast aluminum, which possess hypoeutectic microstructure (Li et al., 2015). Up to the present time, many studies have presented the mechanical properties of SLM-AlSi10Mg alloy. The mechanical properties and microstructure of AlSi10Mg produced by selective laser melting (SLM) or DMLS techniques can be controlled using different parameters, such as feedstock powder (Asgari et al., 2017), and process parameters (Olakanmi et al., 2015). The microstructure and mechanical properties of AlSi10Mg can also be controlled using post heat treatment after SLM process Li et al., 2016). The mechanical properties of SLM-AlSi10Mg are sensitive to strain rate and can both change under quasi-static (Rosenthal et al., 2017) and high strain rates (Asgari et al., 2018). However, a significant knowledge gap in available literature regarding modeling these behaviours, and especially micromechanical modeling of dynamic behaviour."

Jan 1, 2018

By Bruce Bryant

Silver ore was discovered at Aspen in 1879, but the district did not reach full production until 1888 after lawsuits were settled and railroads furnished less expensive transportation to the outside world. The boom years were 1888-92; production declined thereafter. From the middle 1920's until 1950, the Midnight mine in the Richmond Hill district furnished most of the output in the Aspen quadrangle. Since 1950, little mining has been done at Aspen. The metals produced were silver, lead and zinc. Native silver dissolved from the sulfide ores was redeposited by waters circulating as deep as 300 m below the land surface, resulting in great secondary enrichment of many of the deposits. Over 100 million ounces of silver were produced in the Aspen quadrangle. Low-grade lead-zinc deposits remain between the old workings locally, and data available suggest that primary ore below levels mined is also of low grade. The ore occurs in the Mississippian Leadville Limestone and the lower part of the Pennsylvanian Belden Formation in sites that were made favorable for deposition by a number of stratigraphic and structural factors.

Jan 1, 1982

By F. B. Samani, B. Stabel

The 1,000 MW Hydro Power Station Masjed-e-Soleiman (formerly called Godar-e-Landar) in Iran is under construction since 1992. The rock engineering aspects of the major underground structure, i.e. the powerhouse cavern shall be reported on in detail. The geotechnical investigations are described and results given. The results of several geotechnical analyses are presented. The designed and executed rock support is given. A description of the monitoring systems and typical measurement results obtained during and after excavation are presented. The lessons learnt during construction of the Stage-I powerhouse cavern were applied on the extension of the powerhouse cavern, which is to house an additional 1000 MW. Details regarding the unexpected behaviour of the Mudstones are given. Die 1000 MW Wasserkraftanlage Masjed-e-Soleiman (vormals Godar-e-Landar genannt) befindet sich seit 1992 in Bau. Dieser Artikel berichtet im Detail über die felsbaulichen Aspekte der Untertagebauwerke, insb. der Maschinenkaverne. Die geotechnischen Untersuchungen werden beschrieben und deren Ergebnisse wie die Ergebnisse verschiedener Berechnungen werden präsentiert. Die geplante und die ausgeführte Felssicherung wird angegeben. Die eingebauten Überwachungseinrichtungen werden beschrieben und typische Ergebnisse während des Aushubs und danach werden dargestellt. Die Erfahrungen beim Aushub der Kaverne der Stufe I wurden beim Entwurf der Kaverne der Erweiterungsstufe II, die weitere 1000 MW beherbergen wird, berücksichtigt. Details zum unerwarteten Verhalten des Schluff-/Tonsteins werden angegeben. La centrale hydroélectrique de Masjed-e-Soleiman (dénommée anciennement Godar-e-Landar), d’une puissance de 1.000 MW, est en construction depuis 1992. Un rapport détaillé sera présenté sur les aspects relatifs à la construction en enrochements de l’aménagement souterrain principal, à savoir la caverne abritant la salle des machines. Une description des investigations géotechniques réalisées y est fournie ainsi que les résultats correspondants. En outre sont présentés les résultats de plusieurs analyses géotechniques. L’ancrage dans la roche tel que projeté et réalisé est présenté. Une description des systèmes de contrôle ainsi que les résultats de mesures typiques obtenus au cours des travaux d’excavation sont donnés. Les leçons tirées lors de la construction de la Phase 1 de la caverne de la salle des machines furent appliquées à l’extension de la caverne de la salle des machines, qui doit abriter une unité supplémentaire d’une puissance de 1.000 MW. Par ailleurs, des détails sont donnés sur le comportement inattendu des argilites.

Jan 1, 2003

By Hernán Parra

Las pruebas cerradas de flotación (ICFT) son necesarias para el diseño de plantas a niveles de prefactibilidad y factibilidad, ya sea en proyectos greenfield o brownfield. Estas pruebas se realizan después de haber hecho un estudio previo de flotación batch y se usan para simular un circuito continuo. En este trabajo se reseñan los estudios sobre el tema, se busca establecer la manera adecuada de ejecutar la práctica de laboratorio y de evaluar los resultados experimentales, con el propósito de introducir mejoras en el diseño de plantas.

Aug 30, 2017

By Raymond E. Davis

LET'S imagine we are at the Grand L Coulee Dam, where daily 15,000 barrels of low-heat Portland cement and 27,000 tons of processed aggregate in various sizes are mixed to produce 30,000 tons of concrete. Inspect the autographic records which show for each 4-cu-yd. mixer batch of concrete the weights of its constituent materials including its several sizes of aggregate, cement, and water, and which also show the period of mixing and the consistency of the mix. Watch the inspectors sample and test the aggregate for gradation and moisture content of sand, and sample the concrete for homogeneity. Watch the huge buckets deposit the concrete in the forms. It looks too dry to handle, but the concrete vibrators make it melt away. Just enough vibration fully to com- pact the mass, but not enough to produce segregation of the materials; the inspector says when. See the sprinkler system covering all hardening concrete with a spray so that it may not thirst for water. Watch the cleaning of the top of an old lift preparatory to placing a new lift; the sand blasting; the blow-down; the mop-up; the minute inspection.

Jan 1, 1939

By Manuel Gutierrez, Roberto Gomez, Juan Aravena, Johan Gjoevad

The use of explosives in mining operations is a process that involves the search for an ideal explosive for the type of geological condition of the mineral to be extracted. For the explosives present on the market the majority are based on Ammonium Nitrate. This as it is an ideal balance of high energy efficiency achieved with low development of gas emission. The manufacturing and loading operation of the explosive requires multiple process stages and different raw materials, which, if is not correctly supervised and controlled may cause the development of harmful gases or, in the worst case, even toxic gases. The majority of mining operations are located at remote locations without the presence of communities, and hence individuals, which could be affected by emission of the harmful or even toxic gases. In these operations the protection is mainly to protect the employees of the operation. However, if the operation is located near communities, the effect of these gases becomes a serious problem. The communities' perception of post-blasting gases, according to interviews carried out in this project, describes these as smells of black gunpowder, damp soil with a volatile permanence and medium intensity, sometimes a stinking tone is added. The legislation in Chile that controls the exposure of “workers” to different gases is Supreme Decree 594, 2019 (Decreto Supremo 594). Currently the Chilean Ministry of Environment and Sernageomin (Servicio Nacional de Geología y Minería) are taking actions to reform and strengthen oversight, seeking through a short law to provide more tools to the government to decentralize decisions in case of non-compliance with the decree. This paper describes the development and implementation of a permanent and remote gas monitoring system, considering the reasons for choosing the gases to be included in the equipment, the types of sensors and their capabilities, the way to verify in the field the correct functioning of the technology throughout the project, and finally how the data collected in the field is meeting the government's expectations in terms of permanent and online reportability. Additionally, it addresses the continuity of gas monitoring in the community that will disappear in the short term due to the expansion of mining operations, thereby ensuring the protection of both workers and affected communities.

Jan 21, 2025

By H. Akbari

Ordinary portland cement (OPC) is the key pozzalonic component of the concrete mix widely used as a construction material worldwide. B illions of tons of OPC are used in the construction industry each year. However, calcinations of limestone and silica that produce OPC also produce almost an equal amount of C O2 during the cement manufacturing process. Thus, OPC production accounts for nearly 7% of all anthropogenic C O2 emissions each year. The main objective of this study was to develop a geopolymer-based composite to be used as a substitute for OPC in concrete application to significantly lower the carbon footprint of the construction industry. A waste material produced during the coal combustion process was used as the main raw material for the geopolymer-based composite. It was mostly the nonmetallic content of the F-type fly ash produced from the combustion of bituminous coal. The authors envisioned extracting some of the valuable metal oxides from fly ash prior to using the major nonmetallic portion of the fly ash for geopolymer concrete application. The results obtained from this study showed that the compressive strength of geopolymer concrete compares favorably with that of conventional concrete prepared using OPC.

Dec 1, 2013

By J. P. McGee

As part of a joint U.S. Atomic Energy Commission-Federal Bureau of Mines program for using nuclear energy to supply process heat, a simulated nuclear loop has been constructed to test components. This loop has been operated for more than 1,800 hours at 100 p.s.i.g. Of this period, 23 hours were at 2,500° F. and higher; 540 at 2,000° to 2,500° F.; 840 at 1,500° to 2,000° F.; 200 at 1,000° to 1,500° F.; and 260 below 1,000° F. Leakage at flanges and welds was not a serious problem. A helium-recycle system with gas temperatures of 2,300° to 2,500° F. and a static pressure of 250 p.s.i.g. appears feasible. Difficulties were encountered with the recycle compressor due to thermal distortion of the impeller and shaft. The use of sealed bearings limits compressor operation to the life of the bearings.

Jan 1, 1960

By S Mundell, A Atkins, S van de Water

Geoscientific information management enables the capture, management and delivery of the original geoscientific observations and measurements of the earth’s natural resources. However, original observations and measurements are worth nothing if the quality and integrity of the data can’t be guaranteed. Geoscientific information is one of the fundamental assets enabling miners to make confident and accurate business decisions, whether that is defining a resource model, performing reconciliation, delivering ore reserve reports or meeting environmental compliance requirements. Without access to reliable, validated or verified data it increases the risk of miners using incorrect information for reporting and compliance. Industry codes, such as JORC, or government regulations, such as environmental compliance requirements, must be adhered to and companies should be able to confidently report to these standards. Without having a robust information management framework in place, it becomes a challenge to make trustworthy decisions, report confidently and reduce the risk of non-compliance. As a key initiative, good data governance should form one part of a miner’s information management strategy. Within the mining industry it is common for companies to only consider technology tools as the key focus for compliance whereas a mature information management focus will additionally consider people and process. All three pillars are critical for a miner to have confidence in their data driven decisions. This paper discusses an industry framework for best-practice geoscientific information management based on the observations gathered from analysing data management practices within the mining industry. It focuses on how the three pillars of people, process and technology are crucial elements to improve operational decisions and ensure companies are compliant.

Nov 8, 2021

As students progress further into a degree, the decision of vocation selection, and even more importantly û securing employment in a particular industry sector, can become quite daunting. However, with a little initiative, students can overcome these issues by not only researching what employment opportunities exist, but by applying for summer vacation employment. Undergraduate vacation employment, especially with a world-leading hydrometallurgy research organisation such as the Parker Centre, can dramatically alter a studentÆs perspective of particular industries and possibly even alter their selection of vocation pursuits upon graduating. Students can also use vacation employment to enhance their networking capabilities, technical skills and knowledge by dealing with challenging new topics such as sulfur dioxide leaching, which is also discussed in this article.

Jan 1, 2005

By Corinne Boone

CO2e.com, LLC - launched in November 2000 - aims to be ?the global hub for carbon commerce.? CO2e.com is a subsidiary of the Cantor Fitzgerald Group, one of the world?s leading brokerage firms Recent Investor in CO2e ? Mitsui & Co. Alliance with Cantor Fitzgerald Environmental Brokerage Services Group (CFEBS) Offices in London, Toronto, Tokyo, New York, San Francisco, Los Angeles, Connecticut, Houston Primary Goals/Benefits of ET § Goals of Emissions Trading: ? Permit Industrial Growth/Expansion ? Promote Economic Efficiency and Flexibility in Meeting Air Pollution Standards § Benefits of Emissions Trading: ? Enhance Air Quality w/o Economic Stagnation ? Encourage Development of New Technology ? Foster Most Efficient Use of a Limited Resource -- Clean Air § Contributes to Sustainable Development and objectives of UNFCCC, Kyoto Protocol?.

Nov 1, 2002

By Martín Antonio Encinas‐Romero, Patricia Guerrero‐Germán, Jesús Leobardo Valenzuela‐García, José R. Parga‐Torres, María A. Bracamontes‐Landavazo, Agustín Gómez‐Alvarez

A study was carried out to process a sulfide mineral concentrate from Norwest of Mexico containing 97 g/t Au, 0.15% Cu, and 15% Fe. An oxidative acid pretreatment was investigated using ferric sulfate as oxidant, followed by leaching of gold with sodium cyanide. Scanning electron microscopy, SEM-EDS, and X-ray diffraction, XRD, the analysis confirms the presence of quartz and pyrite species. First, a leaching was carried out without pretreatment, at ambient conditions, T = 25 °C and P = 1 atm, obtaining only a 45.2% gold extraction. Once the presence of Fe and Cu sulfides had been confirmed, the Eh-pH diagrams were constructed for the Fe-S-H2O and Cu-S-H2O systems, where it is appreciated that pyrite and chalcocite can dissolve with high oxidation potentials and forming sulfur, oxidizing to sulfate at highly acidic conditions. The oxidized concentrate was neutralized and adjusted to pH > 10.5; it was leached at ambient conditions, at different particle sizes, 44, 37, and 26.5μm, achieving an Au extraction of 75% using a concentration of 0.5% NaCN, 26.5μm particle size, 20% solids, and P = 1atm. Then the oxidized material was subjected to different temperatures, 25, 50, and 70 °C, under the same conditions and obtaining Au extractions up to 92% at 70°C. Additionally, the leaching process was compared using an autoclave reactor at moderate pressures, obtaining an increase in the extraction of Au up to 98% in 2 h, at T = 70 °C and P = 0.62 MPa.

Jan 23, 2022

By Georgios Bartzas, Vasiliki Karmali, Konstantinos Komnitsas, Anna Kritikaki, Dimitra Vathi, Stylianos Tampouris, Arne Peys

Large volumes of slags, with varying mineralogical and geochemical characteristics, are produced annually by the ferrous and nonferrous metallurgical industry. Most of them are considered as potential secondary resources and may be valorized, following the principles of circular economy, for the recovery of critical elements, including energy transition metals. Apart from the economic benefits, valorization of slags may contribute to the competitiveness of the metal industry and the conservation of natural resources. Valorization also results in minimization of environmental impacts on soils and waters in slag disposal areas, due to the prevention of solubilization and subsequent migration of potentially hazardous elements. The present study utilizes ferronickel (FeNi) slag for the production of alkali-activated materials. The effects of the main experimental parameters, including sodium hydroxide (NaOH) molarity, silica/sodium oxide (SiO2 /Na2O) molar ratio in the activating solution, precuring and curing time, curing temperature and aging period on several properties of the final products, are assessed.

Apr 1, 2025

By Don Deardorff, Ke Yang, Yingcai Han, Ken Sorensen, Robert Kruger, Mark Petersen, Diane Fiorelli, Larry Goldfarb, Kathryn Petek, Kwabena Ofori-Awuah

Design of deep foundations for lateral loads requires an understanding of soil-foundation-structure response during loading. Lateral loads on a deep foundation (piles) could be due to earthquakes, winds, waves, and/or machine vibrations. Over the years, analysis of response of piles due to lateral loads evolved from closed-form solutions to p-y methods to strain wedge to finite element/finite difference modeling. Although analysis of lateral response of piles and shafts is routinely performed, there is no single guidance document and/or standard for design and testing. Several different analytical methods are available for the analysis, and the resulting design can result in significantly different responses which can create confusion. This is especially true for analyzing and designing piles in potentially liquefiable soils with lateral spread issues under seismic conditions.This guidance document is intended to assist geotechnical engineers, pile designers, and contractors in analysis, design, and testing of piles and drilled shafts for lateral loads. This document discusses the background of different analytical and testing procedures and presents the recommended methods for analysis, design and testing of piles for lateral loads.Chapter 1 defines the different kinds of lateral loads to which a single pile or pile group may be subjected. This first chapter also presents different types of piles used to resist lateral loads.Chapter 2 discusses geotechnical issues related to lateral pile design such as liquefaction and lateral spreading and other non-seismic issues. Also addressed in Chapter 2 is geotechnical site characterization (as related to lateral loads) in terms of site investigation, in-situ testing, geophysical testing, laboratory testing, and estimation of soil/rock properties.Chapter 3 discusses the background and available analytical methods and tools for the analysis and design of single piles and drilled shafts. Several methods of analyses from closed-form elastic solutions to the finite element/finite difference solutions and their applicability are discussed. Available commercial computer software packages for analyzing single piles and drilled shafts are also presented.Chapter 4 expands the discussion of single piles and drilled shafts into the analysis and design of pile groups. In addition, group effects, resistance of pile caps, results of previous experimental and analytical studies, and available analysis tools and software for pile groups are discussed.Chapter 5 presents the issue of lateral resistance of piles and drilled shafts as discussed in different national and international building and non-building codes. A summary of extensive research on several codes are presented to facilitate the compliance with different codes.Chapter 6 discusses structural design issues of individual piles and drilled shafts such as depth of fixity.Chapter 7 discusses soil structure interaction issues related to kinematic and inertial effects due to seismic loading and available methods of analyses.Chapter 8 discusses and presents the typical procedures for the lateral load testing of piles. This guideline was developed as an aid to the practicing engineer in providing information, direction and commentary on the lateral design of deep foundations. Although all reasonable effort has been made to accurately compile the material and information contained herein, no warranty is made with regard to any such material or information and the Deep Foundation Institute assumes no responsibility for any possible errors or any direct or indirect result of the use of any such material or information. It is not intended that this document address every factor affecting lateral design for every situation. Therefore it is the responsibility of the person utilizing information from this document to confirm that it is appropriate and correct for their situation as well as to understand and properly apply

Jan 1, 2012

By Amado Yataco

El presente texto describe un cuadro comparativo sobre la producción minera comprendida entre el período de enero-febrero 2017 y 2016. En este se observa un déficit reiterativo en oro, plata, plomo y estaño y un menor avance en el cobre y zinc, dada la caída de producción metálica en Antamina. Así también se describe la caída de variación del PBI de oro, plata y plomo en febrero del presente año y la participación de cada metal en la generación del PBI minero. Finalmente se describen las exportaciones e importaciones y la evolución de los metales principales de la minería en los últimos siete meses.

May 1, 2017