http://fundaoinvestigation.com/

Access RAS in 03Oct2016.

BARRAGENS SAMARCO, VALE & BHP BILLITON

CLEARY GOTTLIEB & PANEL REPORT Aug.25.2016

Revisão_02 Acesso RAS em 03nov2016

Relatório sobre as causas imediatas da ruptura da Barragem de Fundão, em 05nov2016, no Município de Mariana, MG.

http://fundaoinvestigation.com/wp-content/uploads/general/PR/en/FinalReport.pdf

[91] 29/08/2016: NOTA OFICIAL DA VALE/SAMARCO

Veja o resultado da investigação independente sobre o acidente com a barragem da Samarco

http://www.vale.com/samarco/PT/Paginas/resultado-investigacao-independente-acidente-barragem-fundao-samarco.aspx

Foi realizada nesta segunda-feira, 29ago2016, em Belo Horizonte (MG), a coletiva de imprensa sobre o resultado da investigação independente contratada pela Samarco, e suas acionistas Vale e BHP Billiton a respeito do acidente com a barragem de Fundão, ocorrido em 5 de novembro de 2015. Participaram da coletiva o diretor-presidente da Vale, MURILO FERREIRA, o presidente da Samarco, ROBERTO CARVALHO, o diretor comercial da BHP Billiton, DEAN DALLA VALLE e o líder do painel de investigação, NORBERT MORGENSTERN.

A investigação foi conduzida pela empresa de advocacia Clearly Gottlieb, que formou um painel com quatro dos maiores especialistas em geotecnia do mundo.

Norbert Morgenstern, líder do painel, já trabalhou em mais de 140 projetos de barragens e tem mais de 330 publicações acadêmicas sobre o assunto. Atua como membro, vice-presidente e presidente de uma extensa lista de comitês técnicos em todo o mundo, além de contribuir na transferência de tecnologia aos países em desenvolvimento através das Nações Unidas e outras agências.

Também compõe o painel o chairman do Conselho e ex-CEO da Klohn Crippen Berger Ltd., Bryan Watts, com mais de 35 anos de experiência em projetos de barragem.

Steven Vick, terceiro membro do painel, é autor e consultor independente de engenharia geotécnica, com mais de 40 anos de experiência atuando em avaliações técnicas e de segurança de aterros e barragens de rejeitos.

Completando o time de especialistas, Cassio Viotti é consultor independente de engenharia de barragens, com mais de 45 anos de experiência, especializado em todas as fases de concepção e engenharia de barragens e estruturas hídricas.

Eles analisaram os aspectos técnicos que provocaram a falha na barragem e conduziram testes apropriados. Na investigação, a empresa teve acesso total aos documentos da Samarco, de seus empregados e instalações.

A análise técnica incluiu, dentre outros aspectos, a construção de um modelo 3D em computador da instalação de rejeitos ao longo do tempo; análise aprofundada dos rejeitos depositados na barragem de Fundão para entender suas propriedades e comportamentos; análises dos níveis de saturação da barragem e a passagem de água por ela ao longo do tempo; e testes para entender o papel que os abalos sísmicos poderiam ter desempenhado no colapso da estrutura.

O painel impôs testes de hipóteses para responder às seguintes perguntas:

Por que aconteceu um fluxo fluido de rejeitos?
Por que o fluxo fluido de rejeitos ocorreu no local onde ocorreu?
Por que o fluxo fluido de rejeitos ocorreu no momento em que ocorreu?

A investigação concluiu que o rompimento da barragem foi consequência de uma cadeia de eventos e condições.

Assista ao replay da coletiva de imprensa (a transmissão começa aos 5m10s)

*A versão do site em português só estará disponível a partir de amanhã

Processo para credenciamento de acesso ao Panel Report [em 03nov2016]

1) Acessar site oficial do Panel: http://fundaoinvestigation.com/

2) Após receber e-mail de contra-prova, clicar no link de resposta;

3) Acessar no site do Panel Report o link do pdf do Relatório [disponível somente em inglês?]

The Fundão Tailings Dam Review Panel (the “Panel”).

http://fundaoinvestigation.com/

Access RAS in 03Oct2016.

[I] HOME [PRESENTATION]

This website was created to share the report of the Fundão Tailings Dam Review Panel (the “Panel”). The Panel was constituted by Cleary Gottlieb Steen & Hamilton LLP (“Cleary Gottlieb”) which was retained jointly by Samarco Mineração S.A. (“Samarco”) and its shareholders, BHP Billiton Brasil Ltda. (“BHP Billiton”) and Vale S.A. (“Vale”), to conduct an investigation to determine the immediate cause of the November 5, 2015 Fundão tailings dam (“Fundão Dam”) failure.

The Panel members are Norbert Morgenstern, Steven G. Vick, Bryan D. Watts and Cássio Viotti, who have decades of geotechnical expertise, which they brought to bear in the months since this highly complex investigation began.

The Panel produced the report to Cleary Gottlieb in accordance with its terms of reference exclusively for and at the request of Cleary Gottlieb. Under the terms of reference, the Panel was required to provide its independent and unbiased professional judgment and expertise in connection with the technical analysis undertaken.

The report does not necessarily represent the views of any of Samarco, BHP Billiton, or Vale or any individual or entity other than the Panel. It has not been prepared in response to any third party investigation, inquiry or litigation.

Cleary Gottlieb and the Panel were given full access to Samarco’s documents, employees and facilities, and the Panel had the documents and information necessary to determine the immediate cause of the failure of the Fundão Dam.

Documents and information were obtained from the following parties:

Samarco: Samarco is the Brazilian mining company that owns and operated and managed the Fundão Dam.
Joaquim Pimenta of Pimenta De Avila Consultoria Ltda.: Mr. Pimenta served as the designer and engineer of record from the initiation of the Dam until 2012, and consultant thereafter.
Members of the Independent Tailings Review Board (“ITRB”): The ITRB was a panel of external experienced technical advisors engaged by Samarco from 2009 onward to review and provide advice on its tailings structures, including the Fundão Dam.
VogBR Recursos Hídricos e Geotecnia Ltda.: VogBR was involved in the design of drainage structures and conducted seepage and stability analyses of the Dam.
Integral Engenharia: Integral was involved in the construction of certain drainage structures on the Dam.
GeoFast Centro de Treinamento: GeoFast was involved in the creation of risk assessment parameters for the saturation conditions on the Dam.
Geoestável Consultoria e Projetos: Geoestável conducted hydrogeological studies on the Dam in connection with the project to raise the Dam to an elevation of 940 meters.
DAM Engenharia: DAM conducted seepage and stability analyses in connection with the project to raise the Dam to 940 meters.
NouH Engenharia: NouH designed the process for repairs to certain drainage structures on the Dam.

The Panel’s technical analysis included, among other things,

(i) building of a 3D computer model of the entire tailings facility over time,

(ii) in-depth analyses of the tailings deposited in the Fundão Dam in order to understand their properties and behaviors,

(iii) analyses of levels of saturation in the Fundão Dam and the flow of water through it over time and (iv) testing to understand the role that earthquakes may have played in the collapse of the Fundão Dam.

The Panel did not evaluate documents and information against legal standards, including but not limited to standards regarding liability, intent and the admissibility of evidence in court or other proceedings.

The Panel did not seek documents and information related to fault or responsibility nor did they endeavor to assign fault or responsibility to any person or party, to evaluate whether or not the failure could have been foreseen or prevented, or to gauge environmental or other downstream effects or damages of the Fundão Dam failure.

The Panel assessed and interpreted historical documents and information with the benefit of knowledge learned from intervening events. Thus, the Panel’s findings and conclusions do not imply, and it should not be inferred, that the same findings and conclusions could have been drawn at the time of the events in question. The Panel did not address that question.

At times, the information available to the Panel was inconsistent, unclear or uncorroborated. The Panel did not seek to make credibility determinations in such cases. In evaluating the information available to it, the Panel used its best professional judgment, but recognizes that others could reach different conclusions or ascribe different weight to particular information.

The report should be read as a whole, and individual passages should be viewed in the context of the entire report, including the appendices, which are an integral part of the report. Discussion or analysis that is based, to any extent, on work carried out by third parties – for example, on field or laboratory work commissioned by the Panel – is subject to the same qualifications or limitations to which that work was subject.

In the report, graphics are used to depict information, locations and events. These graphics may be simplified or not to scale and are intended only as an aid to the reader in the context of the discussion that they support.

THE FIRM: Cleary Gottlieb Steen & Hamilton LLP (“Cleary Gottlieb”)

www.clearygottlieb.com

Where We Work

Cleary Gottlieb is positioned to serve clients anywhere in the world. With offices strategically spread across four continents, we regularly assist clients on major matters, and we are fluent in a range of regional and local languages. All Cleary clients enjoy access to the full resources of our offices and lawyers worldwide.

Our 16 offices are located in [global metropolises]

ESTABLISHED 1946

New York [USA]

One Liberty Plaza ; New York, NY 10006

T: +1 212 225 2000

WHO WE ARE

https://www.clearygottlieb.com/about-us/who-we-are

Cleary Gottlieb is a pioneer in globalizing the legal profession. Since 1946 our lawyers and staff have worked across practices, industries, jurisdictions and continents to provide clients with simple, actionable approaches to their most complex legal and business challenges, whether domestic or international. We support every client relationship with intellectual agility, commercial acumen and a human touch.

We have a proven track record for serving with innovation. We are fluent in the many languages of local and global business. And we have achieved consistent success in multiple jurisdictions.

Clients know Cleary for our signature approach to serving their needs:

Ø Skilled resolution of high-profile, complex legal and business challenges

Ø A sharp focus on the issues that matter most

Ø A commitment to addressing our clients’ immediate needs and advancing their longer-term strategic goals

One World, One Firm

We have 16 offices in major financial centers around the world, but we operate as a single, integrated global partnership and not a U.S. firm with a network of overseas locations.

Ø All Cleary clients enjoy access to the full resources provided by our offices and lawyers worldwide.

Ø The firm employs approximately 1,200 lawyers from more than 50 countries.

Ø Cleary received Chambers and Partners’ inaugural International Law Firm of the Year award, recognizing our global practice and our pioneering tradition of developing homegrown talent in the different countries where we operate.

Clients

We serve:

· International and national business organizations

Ø Financial institutions

Ø Sovereign governments and their agencies

Ø Nonprofits and community organizations

Ø Civil rights and human rights groups

Partnership and Firm Culture

Our firm’s organization and governance emphasize democratic and participatory ideals. To promote the full application of Cleary’s resources in the best service of our clients’ needs, we operate on a seniority-based compensation system for all of our lawyers and we expect each partner to contribute equally to the firm’s success.

We strive to admit to our partnership lawyers with demonstrated qualities of character, leadership and intelligence, who have the proven legal skills that will enable them to contribute significantly to our practice over the long term.

Ø Over 40 percent of our partners are based outside of the United States.

Ø More than one-third of our partners have served in two or more Cleary offices.

Ø Approximately 90 percent of our current partners joined the firm as associates.

Ø Our partnership as a whole decides all important firm matters, including considering candidates for partnership, while committees of partners and counsel under the guidance of the managing partner conduct the day-to-day management of the firm.

Our associates also actively participate in a number of important committees in various offices on a range of issues, including diversity, professional development and recruiting.

Consistent with the vision of our founders, Cleary remains committed to building a community focused on openness, diversity, individuality and collegiality. Learn more about our firm’s diversity initiatives here.

The essence of the firm’s culture is represented by our lawyers: talented and intellectually accomplished people of all nationalities, races and interests, who believe that the practice of law is a privilege that carries responsibility. Together we apply our legal knowledge for the benefit of those in need, dedicating a substantial amount of time and resources to pro bono legal work and other community activities. Learn more about Cleary’s pro bono program here.

[II] THE EXPERT PANEL

Norbert Morgenstern, Chair
Curriculum Vitae

Norbert Morgenstern is an internationally recognized authority in the field of geotechnical engineering. He has extensive experience in dam engineering and has worked on over 140 dam projects and served on numerous technical committees throughout the world, including chairing the panel conducting the review into the cause of the failure of the Mount Polley tailings dam in 2014. He is Professor Emeritus of Civil Engineering at the University of Alberta, and has authored over 330 publications in the field of engineering and received a plethora of honors and awards throughout his career.

Steven G. Vick

Mr. Vick is an internationally recognized geotechnical engineer and review consultant with over 40 years of experience, including both technical reviews and forensic investigations. He chaired the investigation of the Omai tailings dam failure for the government of Guyana in 1995 and served as a member of the Mount Polley Independent Investigation and Review Panel in 2014. He has authored two books, including a comprehensive textbook on tailings dams, and published several articles related to dam safety and risk analyses.

Bryan D. Watts
Curriculum Vitae

Mr. Watts is the Chairman of Klohn Crippen Berger Ltd., a leading engineering firm. He has over 40 years of experience in geotechnical engineering in tailings dam design and post-failure investigations. He has provided engineering support for investigations into the Mount Polley tailings dam failure in 2014, the Omai tailings dam failure in 1995, and the Los Frailes tailings dam failure in 1998, and has participated on review boards for a vast array of tailings dam projects around the world. He is an expert in construction monitoring, field investigations, and design engineering, and the recipient of a number of awards for work in the geotechnical engineering field.

Cássio Viotti
Curriculum Vitae

Mr. Viotti is an independent dam engineering consultant with over 45 years of experience. He has extensive engineering experience with dams in Brazil, including serving as President of the International Commission on Large Dams and the Brazilian Committee on Dams. He has also served as the head of the Geotechnical Division and head of Civil Engineering Department for Cemig, a leading Brazilian power company. He has performed rigorous safety inspections for over 70 dams as an independent consultant. He was a visiting professor at the University of Ouro Preto in Minas Gerais, Brazil, where he instructed graduate students in dam engineering, safety and construction for over 20 years.

The expert panel’s work was guided by the terms of reference dated December 26, 2015.

The Seismologists

The aspects of the investigation related to seismicity were conducted by two world-respected seismology experts:

Gail Atkinson
Curriculum Vitae

Dr. Atkinson is Professor of Seismology at the University of Western Ontario and a leading expert in the field of intraplate seismicity, or seismic activity that occurs away from tectonic plate boundaries in places such as Brazil. Dr. Atkinson has been a university professor for over 20 years and authored more than 200 publications.

Ivan Wong
Curriculum Vitae

Mr. Wong is an internationally recognized expert in seismic hazard and seismic risk evaluations with a specialty in seismicity and earthquake ground motions studies. He has more than 40 years of experience and has directed and participated in seismological and geological studies and research in connection with more than 600 facilities, including numerous tailings dams located throughout the world.

[III] THE PANEL REPORT

3.1. THE REPORT [88 pages]

[page 1]: 1.2 The Investigation: This Investigation of the Fundão Tailings Dam failure was commissioned by BHP Billiton Brasil Ltda., Vale S.A. and Samarco Mineração S.A. The firm of Cleary Gottlieb Steen & Hamilton LLP (CGSH) was engaged to conduct the Investigation with the assistance of a panel of experts. The Fundão Tailings Dam Review Panel (Panel) includes four members, all specialist geotechnical engineers in water and tailings dams: Norbert R. Morgenstern (Chair), Steven G. Vick, Cássio B. Viotti, and Bryan D. Watts.

Fundão Tailings Dam Review Panel [report cover]:

Report on the Immediate Causes of the Failure of the Fundão Dam

Panel [Members]

Ø Norbert R. Morgenstern (Chair)

Ø Steven G. Vick

Ø Cássio B. Viotti

Ø Bryan D. Watts

Date: August, 25, 2016.

3.2. APPENDICES [A to K = 11 documents]

3.3. SEISMOLOGIST’S REPORT

[IV] PRIVACY POLICY

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Copyright

[V] GLOSSARY OF TECHNICAL TERMS

http://fundaoinvestigation.com/glossary-of-technical-terms/

Artesian Pressure: a condition that exists when the water table (piezometric surface) lies above the ground surface. This condition occurs when a pervious, saturated soil is confined by an impervious soil.

Beach: subaerial tailings slope between the dam’s crest and the pond.

Berm: an engineered flat cut or earthfill.

Buttress: a berm constructed at the bottom of a slope to increase its stability.

Chimney Drain: a vertical or near vertical zone of filter sand in a dam meant to reduce the water pressure in the downstream zone of the dam.

Compacted Tailings Fill: tailings that are mechanically compacted to increase their density.

Cone Penetration Test or CPT: a penetration test in which a steel cone that has a 60º point is pushed into the ground at a continuous rate of 2cm/s. The resistance to penetration is measured electronically at the cone tip and cone sleeve.

Consolidation Modeling: estimation of the reduction of air void in cohesive soils with time using a variant of Terzaghi’s consolidation equation.

Contractive Tailings: When shearing a loose particle arrangement of tailings, the particles move together and the soil mass compresses.

Conveyor: a mechanical device used to transport bulk materials from one location to another.

Crest: the top of a dam or slope.

Critical State Line (CSL): the boundary between the contractant and dilatant behavior of tailings where soils shear at constant volume. The CSL is usually determined by performing carefully controlled triaxial tests at a variety of void ratios, both drained and undrained.

Cyclic Liquefaction: a temporary condition of zero effective stress and shear resistance under level ground caused by earthquake shaking of loose, saturated granular soils.

Cyclone Sand Placement: placement of the underflow from a cyclone.

Cycloning: the process of separating tailings into coarser, sandy tailings underflow and finer overflow tailings.

Deformation: the displacement or strain of a soil mass in response to loading.

Deformation Analysis: in the case of the Fundão dam, a computer model of the tailings which yields the deformation of the tailings in response to its self-weight.

Deviator Stress: the difference between the major and minor principal stress in soils. Also called the shear stress.

Dilatant Tailings: if tailings particles are in a tightly-packed arrangement, the tailings particles must first move apart in order to move past each other during shearing. This produces an increase in volume of the tailings mass.

Down-Drop Block or ‘Graben’: a depressed block of soil or rock that is part of a landslide feature and often bordered by parallel cracks.

Downstream Slope: the slope of a dam or dike farthest away from the tailings pond. Downstream means the direction away from the tailings pond while upstream means the direction towards the pond.

Drainage Blanket: a layer of pervious material placed over foundation material to facilitate drainage of the foundation and/or embankment.

Drained Triaxial Compression Tests: standard soil shear test wherein a cylindrical sample of soil encased in a membrane is subjected to an increasing vertical load while confined by cell pressure. “Drained” means the drainage valves are open so the pore pressure in the sample does not increase. “Undrained” means the drainage valves are closed so the pore pressure can change.

Dynamic Loading: repetitive inertial loading imposed by vibrating machinery, earthquake shaking, and other sources. Cyclic loading is usually considered a case of dynamic loading imposed by an earthquake.

Dynamic Response: the response of a structure to a dynamic load such as an earthquake shaking. That response can vary from small permanent displacements to catastrophic flow liquefaction events.

Earthfill: compacted soil fill from a local natural source used to construct dams, including starter dams for tailings dams.

Effective Stress: the difference between the total stress and the pore water pressure in an element of soil.

Effective Stress Analysis (ESA): stability analysis that uses drained effective soil strengths and steady state pore water pressures.

Embankment: Equivalent term for dam or dike. The main element of a dam (earthfill).

Engineer Of Record: the qualified engineer responsible for assuring that a tailings dam is designed, constructed, operated, and decommissioned with appropriate concern for health and safety and the environment, and is in alignment with and meets applicable regulations, statutes, guidelines, codes, and standards.

Extrusion: lateral movement of a soft layer in the foundation of a dam.

Extrusion Collapse Tests: triaxial test that follows a stress path in which the confining stresses reduce.

Factor of Safety (FS or FOS): the ratio of the available strength to the shear stress imposed by self-weight and loadings around the soil slope.

Failure Initiation Sequence: sequence of events occurring immediately prior to the failure of the dam by flowslide.

Failure Modes: potential causes of the dam failure evaluated by the Panel.

Fault Tree: schematic demonstrating the process by which the panel considered the possible failure modes for the dam.

FEFLOW: computer software used to model seepage flow in the dam in 3D.

Fines: soil particles finer than 0.074 mm or finer than the No. 200 sieve.

Flowslide: flowsliding or flow liquefaction occurs when the shear stresses required for static equilibrium of a soil mass exceed the shear strength of soil in its liquefied state.

Freeboard: vertical distance between the lowest point on the crest of a dam and the pond level.

Geographic Information System (GIS): computer modeling system used to capture and manipulate spatial and geographical data.

Hydraulically-Discharged Tailings: Tailings that have been discharged from a slurry transport pipeline.

Impoundment: Entire tailings deposit.

Internal Erosion: Internal movement of fine soil particles by seepage due to filter incompatibilities in the ground.

Kananets: flexible high-density polyethylene (HDPE) pipes used to enhance drainage of the El. 826 m blanket drain.

Kilopascal (kPa): unit of pressure measurement equivalent to 1000 newtons per square meter.

Liquefaction: process whereby loose susceptible materials such as sands lose strength due to pore pressure increase and behave like a liquid rather than a solid.

Loading: the imposition of weight.

Mass Balance: a calculation in which the mass or weight of tailings delivered to a tailings dam by a slurry pipeline is used to calculate the density of the deposited tailings whose volume is known through successive topographic surveys.

Mean Effective Stress: the average of principle effective stresses.

Mobilized Instability Ratio (MIR): the ratio of the deviator stress and mean effective stress to the ratio at the onset of collapse.

Mohr-Coulomb Relationship: the loci of the available resistance of a frictional material as shown on a plot of shear stress versus confining stress. This is the common way of illustrating shear strength at different confining stresses, but one starting density.

Moment Magnitude (Mw): magnitude is a number that characterizes the relative size of an earthquake. Magnitude is based on measurement of the maximum motion recorded by a seismograph. Several scales have been defined. The moment magnitude (Mw) scale, based on the concept of the seismic moment, is uniformly applicable to all sizes of earthquakes.

Newmark-Type Analysis: an analytical technique used to calculate the permanent displacement of soil slopes due to earthquake shaking in the absence of liquefaction.

Norsand Model: a constitutive relationship for sands developed by Jefferies and Been (2016) based on critical state soil mechanics.

One Dimensional-Consolidation Test: a compression test conducted by adding vertical weights to a soil sample in a ring called an oedometer. The vertical deformation of the sample is measured with time after each loading increment is added.

Overflow Channel: the channel constructed between the Dike 2 and Dike 1 reservoirs to decant water to the Secondary Gallery while the Main Gallery was being repaired/decommissioned.

Overtopping: a freeboard of zero whereby the pond water flows over the crest of dam. If the dam is erodible, overtopping usually fails the dam.

Peak Shear Strength: the maximum shear strength that a soil can perform at a given density, confining stress, stress path, and loading rate.

Pellet: the product of iron ore powder, water, and clay, which is baked to form a hard shell used in the production of steel.

Pellet Plant: the facility where iron ore is transformed into pellets used in the production of steel.

Phreatic Surface: water table defined as zero pore pressure.

Piezometer: a device for measuring groundwater pressure.

Piping: internal erosion that develops into an open “pipe” through the soil

Pore Pressure: the water pressure within the voids of a soil mass.

Reinforcement (Equilibrium) Berm: a berm of earthfill or tailings, either compacted or not, put at the toe of a dam or slope to increase the factor of safety by loading the toe.

Reservoir: water pond retained by a dam.

Residual Strength: minimum shear strength of a cohesive soil after displacement along a shear plane or plane of weakness. Also used to describe the minimum undrained strength of a cohesionless soil during a flowslide.

Sand Tailings: defined as the coarser fraction of tailings at Fundão but still contains particles passing the No. 200 sieve.

Saprolite: a soil that retains the fabric or rock from which it has been weathered but has the engineering properties of a soil. In the weathering profile, saprolite is above the transition zone from rock to soil.

Saturated: a condition in which all drainable voids between soil particles are filled with water.

Seepage Flow: groundwater flow after a change in water table.

Seismic Deformation: permanent displacement of sloping ground caused by earthquake shaking. Usually calculated using a variant of the Newmark analysis but only if liquefaction is not involved.

Setback: the upstream relocation of the dam crest alignment on the left abutment of Fundão.

Slimes Tailings: finer fraction of tailings at Fundão which originated at the concentrator.

Slurry: mixture of fine particles of a solid material and liquid which behaves like a relatively uniform liquid when pumped through a pipeline.

Solution Feature: cavities in rock formed as a result of dissolution of the rock by groundwater with time.

Spigot: a pipe connected to a tailings header (or delivery line) used to discharge sand tailings at specific locations to build up the beach. Spigot points at Fundão were routinely moved to raise the crest of the dam uniformly.

Stability Analysis: an analytical or numerical method that compares the available resistance of a soil slope to the imposed shear stresses of that same slope.

Starter Dam: the initial dam in a tailings dam usually built of earthfill to create tailings storage before the mill starts producing tailings.

Static Liquefaction: A type of liquefaction that occurs when the effective stress of soil is reduced essentially to zero, corresponding to complete loss of shear strength, resulting from a single sudden occurrence of change in stress (“monotonic loading”), rather than a cyclic event (such as an earthquake or vibration). A soil in a loose state, and one which may generate significant pore water pressure on a change in load, are most likely to liquefy. This is because loose soil has the tendency to compress when sheared, generating large excess pore water pressure as load is transferred from the soil skeleton to adjacent pore water during undrained loading. As pore water pressure rises, a progressive loss of strength of the soil occurs as effective stress is reduced. It is more likely to occur in sandy or non-plastic silty soils, but may in rare cases occur in gravels and clays.

Static Load: a constant load calculated according to Newton’s Second Law.

Stratigraphy: the layering of soil and rock.

Tailings: finely ground rock particles remaining after the iron ore extraction process.

Tailings Beach: see “Beach”.

Toe: the intersection of dam slope with the natural ground.

Undrained Strength: the strength of a soil when loaded sufficiently fast that pore pressures cannot dissipate. For a given soil, undrained strength is a function of density, stress path, and rate of loading, among many other factors.

Undrained Strength Ratio: the ratio of undrained strength to effective stress.

Unsaturated: a condition in which all drainable voids between soil particles are filled only with air.

Void Ratio (e): the ratio between the volume of the voids and the volume of the solids in a soil.

Water Balance: an accounting of the water inputs and losses to determine the pond level in a tailings dam.

[VI] VIDEO PRESENTATION

http://fundaoinvestigation.com/video-presentation/

[VII] DEMONSTRATIVE ANIMATION

http://fundaoinvestigation.com/demonstrative-animation/

[VIII] APPENDICES

http://fundaoinvestigation.com/appendices/