1st Edition

Geotechnical Design for Sublevel Open Stoping

By Ernesto Villaescusa Copyright 2014
    542 Pages 431 Color Illustrations
    by CRC Press

    The first comprehensive work on one of the most important underground mining methods worldwide, Geotechnical Design for Sublevel Open Stoping presents topics according to the conventional sublevel stoping process used by most mining houses, in which a sublevel stoping geometry is chosen for a particular mining method, equipment availability, and work force experience. Summarizing state-of-the-art practices encountered during his 25+ years of experience at industry-leading underground mines, the author:

    • Covers the design and operation of sublevel open stoping, including variants such as bench stoping
    • Discusses increases in sublevel spacing due to advances in the drilling of longer and accurate production holes, as well as advances in explosive types, charges, and initiation systems
    • Considers improvements in slot rising through vertical crater retreat, inverse drop rise, and raise boring
    • Devotes a chapter to rock mass characterization, since increases in sublevel spacing have meant that larger, unsupported stope walls must stand without collapsing
    • Describes methodologies to design optimum open spans and pillars, rock reinforcement of development access and stope walls, and fill masses to support the resulting stope voids
    • Reviews the sequencing of stoping blocks to minimize in situ stress concentrations
    • Examines dilution control action plans and techniques to back-analyze and optimize stope wall performance

    Featuring numerous case studies from the world-renowned Mount Isa Mines and examples from underground mines in Western Australia, Geotechnical Design for Sublevel Open Stoping is both a practical reference for industry and a specialized textbook for advanced undergraduate and postgraduate mining studies.

    Introduction
    Mining Method Selection
    Self-Supported Mining Methods
    Sublevel Open Stoping
    Factors Controlling Stope Wall Behaviour
    Scope and Contents of This Book
    Sublevel Stoping Geometry
    Introduction
    Stoping Geometries
    Multiple Lift Open Stoping
    Single Lift Stoping
    Shallow Dipping Tabular Orebodies
    Bench Stoping
    Planning and Design
    Introduction
    Geological and Geotechnical Characterisation
    Stress Analysis in Stope Design
    Design of Stoping Blocks
    Detailed Stope Design
    Rock Mass Characterisation
    Introduction
    Characterisation from Exploration Core
    Analysis of Logging Data
    Geotechnical Mapping of Underground Exposures
    Analysis of Mapping Data
    Intact Rock Strength
    The Mechanical Properties of Rock Masses
    Rock Stress
    Span and Pillar Design
    Background
    Empirical Span Determination Using Rock Mass Classification Methods
    The Stability Graph Method
    Numerical Modelling of Stope Wall Stability
    Pillar Stability Analysis
    Drilling and Blasting
    Introduction
    Longhole Drilling
    Blast Design Parameters
    Ring Design
    Explosive Selection
    Explosive Placement
    Initiation Systems
    Raise and Cut-Off Slot Blasting
    Trough Undercut Blasting
    Rock Diaphragm Blasting
    Rock Reinforcement and Support
    Introduction
    Terminology
    Ground Support Design
    Rock Bolting of Open Stope Development Drives
    Cable Bolting of Open Stope Walls
    Cable Bolt Corrosion
    Cement Grouting of Cable Bolts
    Support Systems
    Mine Fill
    Introduction
    Unconsolidated Rock Fill
    Cemented Rock Fill
    Hydraulic Fill
    Cemented Paste Fill
    Open Stope Fill Operations Systems
    Fill Monitoring and Quality Control
    Dilution Control
    Introduction
    Types of Dilution
    Economic Impact of Dilution
    Parameters Influencing Dilution
    Cavity Monitoring System (CMS)
    Dilution Control Plan
    Scale-Independent Measures of Stope Performance

    Biography

    Ernesto Villaescusa possesses over 25 years of applied research experience. He has worked with mining houses such as MIM Holdings, Noranda, WMC Resources, Peñoles, Minera Autlan, CODELCO, BHP Billiton, Placer Dome Asia Pacific, and Normandy to develop guidelines for effective underground mining leading to the safe, economical extraction of ore. For the past 16 years, he has served as professor of mining geomechanics at the Western Australian School of Mines, where he has secured over $21 million of industry-funded mining research income, supervised over 30 masters and 10 Ph.D student theses, and been appointed to an industry chair in mining rock mechanics.

    "Because of its continuing importance in most of the world’s major metalliferous mining countries including, but not only, Australia, Canada, and the Scandinavian and South American countries, it is entirely appropriate that a book should now appear synthesizing 40 years’ accumulated international experience with modern sublevel open stoping methods. … The author…is supremely well qualified to undertake this important task…because of his directly relevant industry, applied research, teaching and consulting experience, and his extensive list of publications in the area. …Although, as the title suggests, the book has a geotechnical engineering orientation, it also contains considerable practical detail on open stoping layouts, design, and operations, and includes chapters on drilling and blasting, rock support and reinforcement, mine fill technology, and dilution control. …I believe that this book will serve multiple purposes. It will serve as a specialist textbook for mining courses at the advanced undergraduate and postgraduate levels. It will also provide an authoritative, practically oriented reference work for those involved in the industry, both in mining operations and as consulting engineers, particularly for those in the early stages of their careers and those seeking to develop new understandings and skills."
    —From the Foreword by Edwin T. Brown, AC, Senior Consultant, Golder Associates Pty Ltd, Brisbane, Australia and Emeritus Professor, University of Queensland, Australia