Guidelines for mine waste dump and stockpile design

385 Pages·029.602 MB·English

by  Mark Hawley, John Cunning (eds.)

G U I D E L I N E S F O R
Mine Waste Dump and Stockpile Design
EDITORS: MARK HAWLEY AND JOHN CUNNING
G U I D E L I N E S F O R
Mine Waste Dump and Stockpile Design
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G U I D E L I N E S F O R
Mine Waste Dump and Stockpile Design
EDITORS: MARK HAWLEY AND JOHN CUNNING
© CSIRO 2017
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National Library of Australia Cataloguing-in-Publication entry
Hawley, Mark, author.
Guidelines for mine waste dump and stockpile design / Mark Hawley and John Cunning.
9781486303502 (hardback)
9781486303519 (ePDF)
9781486303526 (epub)
Includes bibliographical references and index.
Waste products – Storage – Handbooks, manuals, etc.
Mines and mineral resources – Waste disposal – Handbooks, manuals, etc.
Mineral industries – By-products – Waste disposal – Handbooks, manuals, etc.
Mineral industries – Waste disposal – Environmental aspects – Handbooks, manuals, etc.
Australian.
Cunning, John, author.
622
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Front cover: Main waste dump at the Pierina gold mine, Huaraz, Peru. Photographed by R. Sharon. Courtesy Minera Barrick Misquichilca S.A.
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Contents
Preface and acknowledgements xiii
1 Introduction 1
Mark Hawley and John Cunning
1.1 General 1
1.2 Historical context 2
1.3 The Large Open Pit Project 5
1.4 Waste rock dump surveys and databases 5
1.4.1 1991 British Columbia waste dump survey 5
1.4.2 Database of mine waste dump failures 6
1.4.3 British Columbia Ministry of Energy, Mines and Natural Gas database
of waste dump incidents 6
1.4.4 2013 Large Open Pit waste dump, dragline spoil and stockpile survey 6
1.5 Terminology 6
1.6 Waste dump and stockpile types 7
2 Basic design considerations 13
Mark Hawley
2.1 General 13
2.2 Site selection factors 13
2.2.1 Regulatory and social factors 15
2.2.2 Mining factors 17
2.2.3 Terrain and geology factors 18
2.2.4 Environmental factors 18
2.2.5 Geotechnical factors 19
2.2.6 Fill material quality factors 20
2.2.7 Closure factors 20
2.3 Initial site identification 21
2.3.1 Preliminary ranking of potential sites 21
2.4 Conceptual design 21
2.5 Pre-feasibility design 23
2.6 Feasibility design 23
2.7 Detailed design and construction 24
2.8 Operation 24
2.9 Closure 24
2.10 Study requirements 24
3 Waste dump and stockpile stability rating and hazard
classification system 29
Mark Hawley
3.1 Introduction 29
vi Guidelines for Mine Waste Dump and Stockpile Design
3.2 Waste dump and stockpile stability rating and hazard classification system 31
3.2.1 Regional setting 33
3.2.2 Foundation conditions 34
3.2.3 Material quality 41
3.2.4 Geometry and mass 44
3.2.5 Stability analysis 45
3.2.6 Construction 47
3.2.7 Performance 49
3.2.8 Waste dump and stockpile stability rating 49
3.2.9 Waste dump and stockpile hazard class 50
4 Site characterisation 55
Michael Etezad, John Cunning, James Hogarth and Geoff Beale
4.1 Introduction 55
4.1.1 Conceptual studies 55
4.1.2 Planning of field investigations 56
4.2 Site characterisation methods 56
4.3 Study areas 56
4.3.1 Physiography and geomorphology 56
4.3.2 Geology 63
4.3.3 Natural hazards 64
4.3.4 Climate 68
4.4 Field investigations for geotechnical conditions 69
4.4.1 Planning of geotechnical field investigations 69
4.4.2 Foundation investigations 70
4.4.3 Errors and deficiencies in geotechnical site investigations 77
5 Material characterisation 79
Leonardo Dorador, John Cunning, Fernando Junqueira and Mark Hawley
5.1 Introduction 79
5.1.1 Definitions 79
5.2 Foundation materials 80
5.3 Foundation soils 80
5.3.1 Soil description versus classification 80
5.3.2 Soil description 80
5.3.3 Soil index properties 81
5.3.4 Soil classification 84
5.3.5 Shear strength 85
5.3.6 Hydraulic conductivity 86
5.3.7 Consolidation and creep 87
5.3.8 Permafrost and frozen ground 87
5.4 Foundation bedrock 87
5.4.1 Rock characterisation standards and methods 87
5.4.2 Bedrock geology and rock types 88
5.4.3 Intact rock strength 88
5.4.4 Alteration and weathering 88
5.4.5 Discontinuities and fabric 88
5.4.6 Rock mass classification 89
5.4.7 Rock mass strength 89
Contents vii
5.4.8 Mineralogy and petrography 90
5.4.9 Durability 91
5.4.10 Hydraulic conductivity 91
5.5 Waste dump and stockpile fill materials 91
5.5.1 Rockfill 91
5.5.2 Overburden and mixed fills 97
6 Surface water and groundwater characterisation 99
Geoff Beale
6.1 Introduction 99
6.2 Investigation of surface water and groundwater 99
6.2.1 Components of the investigation program 99
6.2.2 Planning considerations 100
6.2.3 Investigation of conditions upgradient and beneath the footprint
of the facility 100
6.2.4 Investigation of conditions within and downgradient of the facility 104
6.3 Conceptual hydrogeological model 105
6.3.1 Hydrogeological characterisation of waste dump and stockpile materials 106
6.3.2 The initial water content of the placed materials 107
6.3.3 Recharge entering the waste dump 108
6.3.4 Flow pathways through the dump materials 108
6.3.5 Discharge of water from the facility 110
6.3.6 Changes with time 111
6.3.7 Approach for characterisation studies 111
6.3.8 Chemical characterisation 112
6.4 Surface water characterisation 113
6.4.1 Introduction 113
6.4.2 Estimating the magnitude of runoff events from small
upgradient catchments 113
6.4.3 Estimating the magnitude of runoff from the waste dump or stockpile 115
6.5 Infiltration and recharge 115
6.5.1 Near-surface water balance 115
6.5.2 Spatial variations 116
6.5.3 Effective rainfall 118
6.5.4 Modelling of infiltration and recharge 118
6.6 Hydrogeological modelling of the waste dump/stockpile facility 120
6.6.1 Objectives 120
6.6.2 Consideration of transient conditions 120
6.6.3 The influence of loading on hydraulic properties 120
6.6.4 Modelling approach 121
6.6.5 Rules of thumb 121
6.6.6 Analytical approach 122
6.6.7 Numerical analysis 122
6.6.8 Prediction of seepage chemistry 125
6.7 Modelling of the foundation materials 126
6.7.1 Characterisation 126
6.7.2 Pore pressure modelling 127
viii Guidelines for Mine Waste Dump and Stockpile Design
7 Diversions and rock drains 129
James Hogarth, Andy Haynes and John Cunning
7.1 Introduction 129
7.2 Diversion channels 129
7.3 Rock drains 129
7.3.1 CANMET rock drain research program (1992–97) 130
7.3.2 Alignments 132
7.3.3 Design flows 132
7.3.4 Inlet capacity 133
7.3.5 Outlet flow 134
7.3.6 Overflow channel 135
7.3.7 Gradation 135
7.3.8 Geometry 135
7.3.9 Long-term performance 136
7.3.10 Precipitates 137
7.3.11 Instrumentation 137
7.4 Other drainage elements 138
7.4.1 Drainage blankets 138
7.4.2 French drains 138
7.4.3 Chimney drains 139
7.4.4 Toe drains 139
8 Stability analysis 141
Mark Hawley, James Hogarth, John Cunning and Andy Haynes
8.1 Introduction 141
8.2 Factors affecting stability 141
8.2.1 Foundation geometry 141
8.2.2 Foundation conditions 141
8.2.3 Waste dump and stockpile geometry and construction sequence 141
8.2.4 Waste rock and stockpile material characteristics 141
8.2.5 Surface and groundwater conditions 142
8.2.6 Seismicity 142
8.3 Acceptance criteria 142
8.3.1 Historical evolution of stability acceptance criteria 142
8.3.2 Suggested stability acceptance criteria 143
8.3.3 Application of stability acceptance criteria 146
8.4 Failure modes 148
8.4.1 Waste dump or stockpile material failure modes 148
8.4.2 Foundation failures 150
8.4.3 Liquefaction 151
8.5 Static limit equilibrium analysis 152
8.5.1 Infinite slope analysis 153
8.5.2 Plane failure analysis 153
8.5.3 Wedge failure analysis 153
8.5.4 Bi-planar failure analysis 155
8.5.5 Methods of slices 155
8.5.6 Compound or complex failures 156
8.5.7 Probability of failure 157
Contents ix
8.6 Seismic stability analysis 157
8.6.1 Pseudo-static analysis 158
8.6.2 Dynamic analysis 159
8.7 Numerical methods 159
8.7.1 Finite element codes 160
8.7.2 Finite difference codes 160
9 Runout analysis 161
Oldrich Hungr
9.1 Introduction 161
9.2 Materials 161
9.2.1 Mine waste 161
9.2.2 Foundation materials 164
9.3 Landslides resulting from failures of waste dumps 164
9.3.1 Initial failure mechanisms 164
9.3.2 Source volume and failure character 166
9.3.3 Flowslides 167
9.4 Mechanisms of failure propagation 167
9.4.1 Sliding 167
9.4.2 Granular flow 167
9.4.3 Sliding surface liquefaction 168
9.4.4 Earthquake and spontaneous liquefaction 168
9.4.5 Rapid undrained loading 170
9.5 Empirical methods of runout analysis and prediction 170
9.5.1 Travel angle 170
9.5.2 Other empirical correlations 172
9.6 Dynamic runout analysis 174
9.6.1 Framework of dynamic analysis 174
9.6.2 Two- and three-dimensional differential stress-strain analyses 175
9.6.3 Depth-integrated unsteady flow models 175
9.6.4 Boundary conditions for flow analysis 176
9.6.5 Rheological relationships for basal flow resistance 178
9.6.6 Material entrainment 180
9.6.7 Calibration and forecasting 181
9.7 Hazard and risk mapping 183
9.8 Protective measures 183
9.9 An example runout analysis 185
10 Risk assessment 187
Brian Griffin
10.1 Introduction 187
10.2 Definition of risk 187
10.3 Types of risk receptors 188
10.4 Types of risk assessment 189
10.4.1 Qualitative to quantitative 189
10.4.2 Failure modes and effects analysis 189
10.4.3 Logic trees – fault and event trees 191
10.5 Risk mitigation and management 194