About this book
Geotechnical Engineering for Mine Waste Storage Facilities is a comprehensive treatment of the application of geotechnical engineering to site selection, site exploration, design, operation and closure of mine waste storage facilities. The level and content are suitable as a technical source and reference for practising engineers engaged both in the design and operational management of mine waste storage facilities and for senior undergraduate and postgraduate students.
The thirteen chapters follow the sequence of the life cycle of a waste storage facility (characterization, site selection, geotechnical exploration, environmental aspects, testing and compaction) and also consider the use of mine waste as a construction material. Geotechnical Engineering for Mine Waste Storage Facilities is liberally illustrated by both line drawings and photographs, and the theoretical passages are supported by typical test results, worked examples and carefully analysed case histories.
Contents
Chapter 1: Waste Engineering, Characteristics of Mine Wastes and Types of Waste Storage
The nature and magnitude of the mine waste storage activity
Origins and quantities of mine waste
The effects of climate
Waste characteristics
Principles of mine waste management
Types of mine waste storage
Philosophy and arrangement of this book
Chapter 2: Selection of a Site for Storage of Mine Waste
Procedure for site selection
Preliminary assessment of required size of site
Possible fatal flaws in candidate sites
Seeking and obtaining public acceptance
Preliminary ranking of candidate sites
Site feasibility study
Risk analysis
Environmental impact report
Preliminary geotechnical characterization of waste
Preliminary site investigation
Final site selection
Examples of disastrous selection of sites
Chapter 3: Geotechnical Exploration of Sites for Development of Mine Waste Storages
Soil engineering survey
Soil engineering data
Detailed information for design of slopes & seepage control
Profile description
Simple in situ tests and soil sampling
Taking undisturbed soil samples for laboratory testing
Chapter 4: Environmental and Engineering Characteristics of Mine Waste, Including Stress and Strain Analysis and Laboratory Shear Testing
Characteristics having environmental impact
Engineering characteristics
Changes of waste characteristics with time, and other considerations
Analysis of stresses and strains and the principle of effective stress
The behaviour of mine waste materials subjected to shear
The process of consolidation and pore pressure re-distribution in laboratory shear tests
The strength and viscosity of tailings at large water contents
The shear strengths of interfaces
The shear strength of waste rock
Strain softening of "dry’’ coarse mine wastes
The mechanics of unsaturated waste materials
Chapter 5: In Situ Shear Strength Testing of Tailings and Other Waste Materials and Test Interpretation
The shear vane test
The pressuremeter test
The cone penetrometer test
Estimation of potential for liquefaction from cone penetration tests
Chapter 6: Measuring the Coefficient of Permeability in the Laboratory and In Situ, Seepage Flow Nets, Drains and Linings, Geosynthetics, Geomembranes and GCL’s
Measuring permeability
Observed differences between small scale and large scale permeability measurements
Laboratory tests for permeability
Methods for measuring permeability in situ
Estimation of permeability from field tests
Large-scale permeability tests using test pads
The permeability of tailings
Seepage and flow nets
The design of filter drains
Calculation of seepage rates through tailings storages
The processes of consolidation and pore pressure re-distribution
Basal impervious liners and surface cover layers
Blockage of filter drains and geotextiles
Geosynthetic materials
Chapter 7: The Mechanics of Compaction
The compaction process
Uses of compaction in mine waste engineering
The mechanisms of compaction
Relationships between saturated permeability to water flow and water content
Laboratory compaction
Precautions to be taken with laboratory compaction
Compaction in the field
Designing a compacted clay layer for permeability
Seepage through field-compacted layers
Control of compaction in the field
Special considerations for work in climates with large rates of evaporation
Additional points for consideration
Chapter 8: Methods for Constructing Impounding Dykes for Storing Hydraulically Transported Tailings and Other Fine-Grained Wastes
Deposition methods and sequences
Beach formation in hydraulic deposition of fine-grained wastes
Predicting beach profiles
Details of particle size sorting during hydraulic deposition
Effects of particle size sorting on permeability, water content and strength variation down a beach
A comparison of tailings beaches formed in air and in water
Methods for depositing slurries of tailings and other fine-grained waste materials
Operational systems for tailings storages
An example of building an embankment by underwater deposition
Pool control and decanting
Chapter 9: Water Control and Functional and Safety Monitoring for Hydraulic Fill Tailings Storages and Dry Dumps Safety Appraisal Special Considerations for Carbonaceous and Radioactive Wastes
Basis of a water control system
Penstocks or decant towers and spillways
Monitoring systems for waste storages
Appraisal of safety for waste storages
Special considerations for carbonaceous wastes
A note on characteristics of radioactive wastes
Chapter 10: Water Balances for Tailings Storage Facilities and Dry Waste Dumps
Water balances in general
Required data
Components of the water balance for an operational tailings storage
Examples of water balances for operating hydraulic fill tailings storage impoundments
The possibilities for saving water
Seepage from the tailings storage into the foundation strata and the recession of the phreatic surface following cessation of operations
Drainage of interstitial water as the phreatic surface recedes
The water balance for a "dry’’ dump or a closed and rehabilitated tailings storage
Measuring potential infiltration and runoff
Estimating evaporation or evapotranspiration
Measuring evaporation by solar energy balance
Depth to which evaporation extends
The effects of slope angle and orientation on solar radiation received by slopes of waste storages
Water balances for "Infiltrate, Store, Evapotranspire’’ (ISE) covers and for impervious cover layers on mine waste storages
The water balance for a dry ash dump
Disposal of industrial waste liquids by evaporation and capillary storage in waste
The role of soil heat G in evaporation of water from a soil
Further points to consider
Principles of the measuring weir
Chapter 11: Failures of Mine Waste Storages
Failures: causes, consequences, characteristics
Failures of hydraulic fill tailings storages caused by seismic events
Flow failures caused by overtopping
Failure caused by increasing pore pressure
Failures caused by excessive rate of rise
Failure caused by poor control of slurry relative density
Post-failure profiles of hydraulic fill tailings storages
Analysis of the motion of flow failures
The effects of failure geometry on insurance rates
Failures of dumps of coarse wastes
Failures caused by collapse of tailings storages into subterranean caverns or underground workings
Failures of impervious linings installed on steep slopes
Methods for analysis of the stability of slopes
Further points regarding the failure of slopes
Chapter 12: Surface Stability of Tailings Storages Slopes – Erosion Rates, Slope Geometry and Engineered Erosion Protection
Past practice for slope angles of tailings storages
Acceptable erosion rates for slopes
Wind erosion compared with water erosion
Acceptable slope geometry for tailings storages
Protection of slopes against erosion by geotechnical means
Special considerations applying to badly eroded abandoned or neglected tailings storages
The effect of eroded tailings on the surroundings of a storage of sulphidic tailings
Wind speed profiles, amplification factors and wind erosion
Wind speed profiles over natural and constructed slopes
Wind tunnel tests on model waste storages
Erosion and deposition by wind on full size waste storages
Analysis of particle movement in the wind
Summary of points to be considered
Chapter 13: The Use of Mine Waste for Backfilling of Mining Voids and as a Construction Material
Applications of backfilling
Backfilling of shallow underground mine workings to stabilize the surface
The properties of mine waste as a structural underground support in narrow stopes
Measurements in situ of stresses and strains in fills at great depth
Supporting narrow stopes with steel-reinforced granular tailings backfill
The behaviour of steel mesh-reinforced square columns of cemented cyclone tailings underflow (grout packs)
The use of geotextiles for temporary retention of backfill in narrow stopes during hydraulic placing
The use of mine and industrial wastes in surface construction
Customer Reviews
Biography
Geoffrey Blight completed his Bachelor's and Master's degrees in Civil Engineering at the University of the Witwatersrand, Johannesburg and his PhD at the Imperial College of Science and Technology in London. The early years of his career were spent at the South African National Building Research Institute, Pretoria, where he was engaged in research on design, operation and safety of mine waste storage facilities, including waste rock dumps and hydraulic fill tailings storage facilities. After the disastrous failure of a coal waste dump at Aberfan, U.K. in 1966, he was sent on a country-wide inspection tour of South African mines to make sure that no similarly threatening stability situations existed locally. Eleven years later, after the disastrous failure of a hydraulic fill tailings dam at Bafokeng, north of Johannesburg, he was asked by the mining industry to write a comprehensive guide to the design, operation and closure of mine waste storage facilities. This appeared in 1979 and has been revised and updated several times since. Geoff Blight re-joined the Department of Civil Engineering at Witwatersrand University in 1969 and the results of his continuing research and consulting work on mine waste have been widely published since. The present book has been developed from the updated mining industry guide as well as a series of post graduate courses in mine waste management that have been presented for many years. In addition to numerous technical papers published in refereed journals and conference proceedings, he is the editor and co-author of the book Mechanics of Residual Soil (Balkema, 1997) and author of Assessing Loads on Silos and Other Bulk storage Structures (Taylor and Francis 2006).
