Fell / MacGregor / Stapledon Geotechnical Engineering of Dams, 2nd Edition

2. Auflage 2014
ISBN: 978-0-203-38731-3
Verlag: CRC Press
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 1382 Seiten

This book provides a comprehensive text on the geotechnical and geological aspects of the investigations for and the design and construction of new dams and the review and assessment of existing dams. The emphasis is on embankment dams, but much of the text, particularly those parts related to geology, can be used for concrete gravity and arch dams. The book aims to provide practising dam engineers and geologists with a practical approach, as well as to give university students an insight into the subject of dam engineering. The theoretical basis upon which design methods have been developed is included so readers develop a proper understanding of the limitations of the methods. All phases of investigation, design and construction are covered, from the initial assessment of a damsite and the development and carrying out of a detailed site investigation program, through to the preliminary and detailed design phases and ultimately the construction phase. The assessment of existing dams, including the analysis of risks posed by those dams, is also discussed. This wholly revised and significantly expanded 2nd edition includes a lengthy new chapter on the assessment of the likelihood of failure of dams by internal erosion and piping.

Autoren/Hrsg.

Fell, Robin

MacGregor, Patrick

Stapledon, David

Bell, Graeme

Foster, Mark

Fachgebiete

• Technische Wissenschaften Bauingenieurwesen Bauingenieurwesen

Inhaltsverzeichnis

1 Introduction
1.1 Outline of the Book
1.2 Types of Embankment Dams and Their Main Features
1.3 Types of Concrete Dams and Their Main Features

2 Key Geological Issues
2.1 Basic Definitions
2.2 Types of Anisotropic Fabrics
2.3 Defects in Rock Masses
2.3.1 Joints
2.3.2 Sheared and Crushed Zones (Faults)
2.3.3 Soil Infill Seams (or Just Infill Seams)
2.3.4 Extremely Weathered (or Altered) Seams
2.3.5 the Importance of Using the Above Terms to Describe Defects in Rock
2.4 Defects in Soil Masses
2.5 Stresses in Rock Masses
2.5.1 Probable Source of High Horizontal Stresses
2.5.2 Stress Relief Effects in Natural Rock Exposures
2.5.3 Effects in Claystones and Shales
2.5.4 Special Effects in Valleys
2.5.5 Rock Movements in Excavations
2.6 Weathering of Rocks
2.6.1 Mechanical Weathering
2.6.2 Chemical Decomposition
2.6.3 Chemical Weathering
2.6.3.1 Susceptibility of Common Minerals to Chemical Weathering
2.6.3.2 Susceptibility of Rock Substances to Chemical Weathering
2.6.4 Weathered Rock Profiles and Their Development
2.6.4.1 Climate and Vegetation
2.6.4.2 Rock Substance Types and Defect Types and Pattern
2.6.4.3 Time and Erosion
2.6.4.4 Groundwater and Topography
2.6.4.5 Features of Weathered Profiles Near Valley Floors
2.6.5 Complications Due to Cementation
2.7 Chemical Alteration
2.8 Classification of Weathered Rock
2.8.1 Recommended System for Classification of Weathered Rock Substance
2.8.2 Limitations on Classification Systems for Weathered Rock
2.9 Rapid Weathering
2.9.1 Slaking of Mudrocks
2.9.2 Crystal Growth in Pores
2.9.3 Expansion of Secondary Minerals
2.9.4 Oxidation of Sulphide Minerals
2.9.4.1 Sulphide Oxidation Effects in Rockfill Dams – Some Examples
2.9.4.2 Possible Effects of Sulphide Oxidation in Rockfill Dams
2.9.4.3 Sulphide Oxidation – Implications for Site Studies
2.9.5 Rapid Solution
2.9.6 Surface Fretting Due to Electro-Static Moisture Absorption
2.10 Landsliding at Dam Sites
2.10.1 First-Time and "Reactivated" Slides
2.10.1.1 Reactivated Slides
2.10.1.2 First-Time Slides
2.10.2 Importance of Early Recognition of Evidence of Past Slope Instability at Dam Sites
2.10.3 Dams and Landslides: Some Experiences
2.10.3.1 Talbingo Dam
2.10.3.2 Tooma Dam
2.10.3.3 Wungong Dam
2.10.3.4 Sugarloaf Dam
2.10.3.5 Thomson Dam
2.11 Stability of Slopes Around Storages
2.11.1 Vital Slope Stability Questions for the Feasibility and Site Selection Stages
2.11.1.1 Most Vulnerable Existing Or Proposed Project Features, and Parts of Storage Area? – Question 1
2.11.1.2 Currently Active Or Old Dormant Landslides? – Questions 2 and 4 to 7
2.11.1.3 Areas Where First-Time Landsliding May Be Induced (Questions 3 to 7)
2.11.1.4 What Is the Likely Post Failure Velocity and Travel Distance?
2.11.1.5 What Is the Size of Impulse Waves Which May Be Created?
2.12 Watertightness of Storages
2.12.1 Models for Watertightness of Storages in Many Areas of Non-Soluble Rocks
2.12.2 Watertightness of Storage Areas Formed by Soluble Rocks
2.12.3 Features Which May Form Local Zones of High Leakage, From Any Storage Area
2.12.4 Watertightness of Storages Underlain by Soils
2.12.5 Assessment of Watertightness
2.12.5.1 Storages in Non-Soluble Rock Areas – Assessment of Watertightness
2.12.5.2 Storages in Soluble Rock Areas – Assessment of Watertightness
2.12.5.3 Storages Formed in Soils – Assessment of Watertightness
2.12.6 Methods Used to Prevent Or Limit Leakages From Storages

3 Geotechnical Questions Associated With Various Geological Environments
3.1 Granitic Rocks
3.1.1 Fresh Granitic Rocks, Properties and Uses
3.1.2 Weathered Granitic Rocks, Properties, Uses and Profiles
3.1.3 Stability of Slopes in Granitic Rocks
3.1.4 Granitic Rocks: Check List
3.2 Volcanic Rocks (Intrusive and Flow)
3.2.1 Intrusive Plugs, Dykes and Sills
3.2.2 Flows
3.2.2.1 Flows on Land
3.2.2.2 Undersea Flows
3.2.3 Alteration of Volcanic Rocks
3.2.4 Weathering of Volcanic Rocks
3.2.5 Landsliding on Slopes Underlain by Weathered Basalt
3.2.6 Alkali-Aggregate Reaction
3.2.7 Volcanic Rocks (Intrusive and Flow) Check List of Questions
3.3 Pyroclastics
3.3.1 Variability of Pyroclastic Materials and Masses
3.3.2 Particular Construction Issues in Pyroclastics
3.3.3 Pyroclastic Materials – Check List of Questions
3.4 Schistose Rocks
3.4.1 Properties of Fresh Schistose Rock Substances
3.4.2 Weathered Products and Profiles Developed in Schistose Rock
3.4.3 Suitability of Schistose Rocks for Use as Filter Materials, Concrete Aggregates and Pavement Materials
3.4.4 Suitability of Schistose Rocks for Use as Rockfill
3.4.5 Structural Defects of Particular Significance in Schistose Rocks
3.4.5.1 Minor Faults Developed Parallel and at Acute Angles to the Foliation
3.4.5.2 Kink Bands
3.4.5.3 Mica-Rich Layers
3.4.6 Stability of Slopes Formed by Schistose Rocks
3.4.7 Schistose Rocks – Check List of Questions
3.5 Mudrocks
3.5.1 Engineering Properties of Mudrocks
3.5.2 Bedding-Surface Faults in Mudrocks
3.5.3 Slickensided Joints Or Fissures
3.5.4 Weathered Products and Profiles in Mudrocks
3.5.5 Stability of Slopes Underlain by Mudrocks
3.5.6 Development of Unusually High Pore Pressures
3.5.7 Suitability of Mudrocks for Use as Construction Materials
3.5.8 Mudrocks – Check List of Questions
3.6 Sandstones and Related Sedimentary Rocks
3.6.1 Properties of the Rock Substances
3.6.2 Suitability for Use as Construction Materials
3.6.3 Weathering Products
3.6.4 Weathered Profile and Stability of Slopes
3.6.5 Sandstones and Similar Rocks – List of Questions
3.7 Carbonate Rocks
3.7.1 Effects of Solution
3.7.1.1 Rock Masses Composed of Dense, Fine Grained Rock Substances Comprising More Than 90% of Carbonate (Usually Category O)
3.7.1.2 Rock Masses Composed of Dense Fine Grained Rock Substance Containing 10% to 90% of Carbonate (Usually Category O)
3.7.1.3 Rock Masses Composed of Porous, Low Density Carbonate Rock Substance (Usually Category Y)
3.7.2 Watertightness of Dam Foundations
3.7.2.1 Dams Which Have Experienced Significant Leakage Problems
3.7.3 Potential for Sinkholes to Develop Beneath A Dam, Reservoir Or Associated Works
3.7.4 Potential for Continuing Dissolution of Jointed Carbonate Rock in Dam Foundations
3.7.5 Potential for Continuing Dissolution of Aggregates of Carbonate Rock Particles and of Permeable Carbonate Substances (Category O Carbonate, in Each Case)
3.7.6 Discussion – Potential for Continuing Dissolution of Carbonate Rocks in Foundations
3.7.6.1 Category O Carbonate Rocks
3.7.6.2 Category Y Carbonate Rocks
3.7.7 Potential Problems With Filters’ Composed of Carbonate Rocks
3.7.7.1 Category O Carbonate Rocks
3.7.7.2 Category Y Carbonate Materials
3.7.8 Suitability of Carbonate Rocks for Embankment Materials
3.7.9 Suitability of Carbonate Rocks for Concrete and Pavement Materials
3.7.10 Stability of Slopes Underlain by Carbonate Rocks
3.7.11 Dewatering of Excavations in Carbonate Rocks
3.7.12 Carbonate Rocks – Check List of Questions
3.8 Evaporites
3.8.1 Performance of Dams Built on Rocks Containing Evaporites
3.8.2 Guidelines for Dam Construction at Sites Which Contain Evaporites
3.8.3 Evaporites – Checklist of Questions
3.9 Alluvial Soils
3.9.1 River Channel Deposits
3.9.2 Open-Work Gravels
3.9.3 Oxbow Lake Deposits
3.9.4 Flood Plain, Lacustrine and Estuarine Deposits
3.9.5 Use of Alluvial Soils for Construction
3.9.6 Alluvial Soils, List of Questions
3.10 Colluvial Soils
3.10.1 Occurrence and Description
3.10.1.1 Scree and Talus
3.10.1.2 Slopewash Soils
3.10.1.3 Landslide Debris
3.10.2 Properties of Colluvial Soils
3.10.2.1 Scree and Talus
3.10.2.2 Slopewash
3.10.2.3 Landslide Debris
3.10.3 Use as Construction Materials
3.10.4 Colluvial Soil – List of Questions
3.11 Laterites and Lateritic Weathering Profiles
3.11.1 Composition, Thicknesses and Origin of Lateritic Weathering Profiles
3.11.2 Properties of Lateritic Soils
3.11.3 Use of Lateritic Soils for Construction
3.11.4 Karstic Features Developed in Laterite Terrain
3.11.5 Recognition and Interpretation of Silcrete Layer
3.11.6 Lateritic Soils and Profiles – List of Questions
3.12 Glacial Deposits and Landforms
3.12.1 Glaciated Valleys
3.12.2 Materials Deposited by Glaciers
3.12.2.1 Properties of Till Materials
3.12.2.2 Disrupted Bedrock Surface Beneath Glaciers
3.12.3 Glaciofluvial Deposits
3.12.4 Periglacial Features
3.12.5 Glacial Environment – List of Questions

4 Planning, Conducting and Reporting of Geotechnical Investigations
4.1 The Need to Ask the Right Questions
4.1.1 Geotechnical Engineering Questions
4.1.2 Geological Questions
4.1.2.1 Questions Relating to Rock and Soil Types, Climate and Topography
4.1.2.2 Questions Relating to Geological Processes, I.E. to the History of Development of the Site
4.1.3 Geotechnical Questions for Investigations of Existing Dams
4.2 Geotechnical Input at Various Stages of Development
4.3 An Iterative Approach to the Investigations
4.4 Progression From Regional to Local Studies
4.4.1 Broad Regional Studies
4.4.1.1 Objectives
4.4.1.2 Activities
4.4.2 Studies at Intermediate and Detailed Scales
4.4.2.1 Objectives
4.4.2.2 Activities
4.5 Reporting
4.6 Funding of Geotechnical Studies
4.7 The Site Investigation Team

5 Site Investigation Techniques
5.1 Topographic Mapping and Survey
5.2 Interpretation of Satellite Images Aerial Photographs and Photographs Taken During Construction
5.2.1 Interpretation of Satellite Images
5.2.2 Interpretation of Aerial Photographs
5.2.2.1 Coverage
5.2.2.2 Interpretation
5.2.3 Photographs Taken During Construction
5.3 Geomorphological Mapping
5.4 Geotechnical Mapping
5.4.1 Use of Existing Maps and Reports
5.4.2 Geotechnical Mapping for the Project
5.4.2.1 Regional Mapping
5.4.2.2 Geotechnical Mapping
5.5 Geophysical Methods, Surface and Downhole
5.5.1 Surface Geophysical Methods
5.5.1.1 Seismic
5.5.1.2 Self Potential
5.5.1.3 Electrical Resistivity
5.5.1.4 Electromagnetic Conductivity
5.5.1.5 Magnetic
5.5.1.6 Microgravity
5.5.1.7 Ground Penetrating Radar
5.5.2 Down-Hole Logging of Boreholes
5.5.3 Cross-Hole and Up-Hole Seismic
5.6 Test Pits and Trenches
5.6.1 Test Pits
5.6.2 Trenches
5.7 Sluicing
5.8 Adits and Shafts
5.9 Drill Holes
5.9.1 Drilling Objectives
5.9.2 Drilling Techniques and Their Application
5.9.3 Auger Drilling
5.9.4 Percussion Drilling
5.9.5 Rotary Drilling
5.9.6 Sonic Drilling
5.10 Sampling
5.10.1 Soil Samples
5.10.2 Rock Samples
5.11 In Situ Testing
5.11.1 In Situ Testing in Soils
5.11.2 In Situ Testing of Rock
5.11.2.1 Borehole Orientation
5.11.2.2 Borehole Impression Packer
5.11.2.3 Borehole Imaging
5.12 Groundwater
5.13 In Situ Permeability Tests on Soil
5.14 In Situ Permeability Tests in Rock
5.14.1 Lugeon Value and Equivalent Rock Mass Permeability
5.14.2 Test Methods
5.14.3 Selection of Test Section
5.14.4 Test Equipment
5.14.4.1 Packers
5.14.4.2 Water Supply System
5.14.4.3 Selection of Test Pressures
5.14.5 Test Procedure
5.14.5.1 Presentation and Interpretation of Results
5.15 Use of Surface Survey and Borehole Inclinometers
5.15.1 Surface Survey
5.15.2 Borehole Inclinometers
5.16 Common Errors and Deficiencies in Geotechnical Investigation

6 Shear Strength, Compressibility and Permeability of Embankment Materials and Soil Foundations
6.1 Shear Strength of Soils
6.1.1 Drained Strength – Definitions
6.1.2 Development of Drained Residual Strength F R 6.1.3 Undrained Strength Conditions
6.1.4 Laboratory Testing for Drained Strength Parameters, and Common Errors
6.1.4.1 Triaxial Test
6.1.4.2 Direct Shear Test
6.1.4.3 Ring Shear Test
6.1.4.4 Comparison of Field Residual With Laboratory Residual Strength Obtained From Direct Shear and Ring Shear 6.1.5 Laboratory Testing for Undrained Strength
6.1.6 Estimation of the Undrained Strength From the Over-Consolidation Ratio (OCR), at Rest Earth Pressure Coefficient Ko, and Effective Stress Strengths
6.1.6.1 Estimation of Undrained Strength From OCR
6.1.6.2 Estimation of Undrained Strength From Effective Stress Shear Parameters
6.1.7 Estimation of the Undrained Strength of Cohesive Soils From in Situ Tests
6.1.7.1 Cone Penetration and Piezocone Tests
6.1.7.2 Vane Shear
6.1.7.3 Self Boring Pressuremeter
6.1.8 Shear Strength of Fissured Soils
6.1.8.1 The Nature of Fissuring, and How to Assess the Shear Strength
6.1.8.2 Triaxial Testing of Fissured Soils
6.1.9 Estimation of the Effective Friction Angle of Granular Soils
6.1.9.1 Methods Usually Adopted
6.1.9.2 In Situ Tests
6.1.9.3 Laboratory Tests
6.1.9.4 Empirical Estimation
6.1.10 Shear Strength of Partially Saturated Soils
6.2 Shear Strength of Rockfill
6.3 Compressibility of Soils and Embankment Materials
6.3.1 General Principles
6.3.1.1 Within the Foundation
6.3.1.2 Within the Embankment
6.3.2 Methods of Estimating the Compressibility of Earth Fill, Filters and Rockfill
6.3.2.1 Using Data From the Performance of Other Dams – Earthfill
6.3.2.2 Using Data From the Performance of Other Dams – Rockfill
6.3.2.3 In Situ Testing
6.3.2.4 Laboratory Testing
6.3.2.5 Tensile Properties of Plastic Soils
6.4 Permeability of Soils
6.4.1 General Principles
6.4.2 Laboratory Test Methods
6.4.3 Indirect Test Methods
6.4.3.1 Oedometer and Triaxial Consolidation Test
6.4.3.2 Estimation of Permeability of Sands From Particle Size Distribution
6.4.4 Effects of Poor Sampling on Estimated Permeability in the Laboratory
6.4.5 In Situ Testing Methods

7 Clay Mineralogy, Soil Properties, and Dispersive Soils
7.1 Introduction
7.2 Clay Minerals and Their Structure
7.2.1 Clay Minerals
7.2.2 Bonding of Clay Minerals
7.2.2.1 Primary Bonds
7.2.2.2 Secondary Bonds
7.2.3 Bonding Between Layers of Clay Minerals
7.3 Interaction Between Water and Clay Minerals
7.3.1 Adsorbed Water
7.3.2 Cation Exchange
7.3.3 Formation of Diffuse Double Layer
7.3.4 Mechanism of Dispersion
7.4 Identification of Clay Minerals
7.4.1 X-Ray Diffraction
7.4.2 Differential Thermal Analysis (DTA)
7.4.3 Electron Microscopy
7.4.4 Atterberg Limits
7.4.5 The Activity of the Soil
7.5 Engineering Properties of Clay Soils Related to the Types of Clay Minerals
7.5.1 Dispersivity
7.5.2 Shrink and Swell Characteristics
7.5.3 Shear Strength
7.5.4 Erosion Properties
7.6 Identification of Dispersive Soils
7.6.1 Laboratory Tests
7.6.1.1 Emerson Class Number
7.6.1.2 Soil Conservation Service Test
7.6.1.3 Pinhole Dispersion Classification
7.6.1.4 Chemical Tests
7.6.1.5 Recommended Approach
7.6.2 Field Identification and Other Factors
7.7 Use of Dispersive Soils in Embankment Dams
7.7.1 Problems With Dispersive Soils
7.7.2 Construction With Dispersive Soils
7.7.2.1 Provide Properly Designed and Constructed Filters
7.7.2.2 Proper Compaction of the Soil
7.7.2.3 Careful Detailing of Pipes Or Conduits Through the Embankment
7.7.2.4 Lime Or Gypsum Modification of the Soil
7.7.2.5 Sealing of Cracks in the Abutment and Cutoff Trench
7.7.3 Turbidity of Reservoir Water

8 Internal Erosion and Piping of Embankment Dams and in Dam Foundations
8.1 The Importance of Internal Erosion and Piping to Dam Safety
8.2 Description of the Internal Erosion and Piping Process
8.2.1 The Overall Process Leading to Failure of A Dam
8.2.2 Initiation of Internal Erosion
8.2.3 Continuation of Erosion
8.2.4 Progression of Erosion
8.2.5 Detection and Intervention
8.2.6 Breach
8.3 Concentrated Leak Erosion
8.3.1 The Overall Process
8.3.2 Situations Where Cracking and Low Stress Zones May Be Present in an Embankment or the Foundation
8.3.2.1 Cracking and Hydraulic Fracture Due to Cross Valley Differential Settlement of the Core
8.3.2.2 Cracking and Hydraulic Fracture Due to Cross Valley Arching
8.3.2.3 Cracking and Hydraulic Fracture Due to Differential Settlement in the Foundation Under the Core
8.3.2.4 Cracking and

Über Autor(innen)

Robin Fell is Emeritus Professor of Civil Engineering at the University of New South Wales, Australia, and also works as a consultant. He has more than 40 years of experience in geotechnical engineering of dams, landslides and civil and mining projects in Australia and Asia. He has worked on over 100 dams worldwide and has been involved in all aspects of planning, site investigation, design and construction of embankment dams.

Patrick MacGregor is a Consulting Engineering Geologist with more than 40 years experience in the assessment of geological constraints for major civil engineering projects in a number of countries. He has been involved in dam investigation, design and construction, and particularly worked on hydroelectric developments at all stages from inception to operation.

David Stapledon spent many years investigating large dam construction sites in various countries. He was a Professor of Engineering Geology at the University of South Australia (1964 -1993) and worked as a Consultant in Engineering Geology, contributing to major dam projects in Australia, New Zealand and South East Asia. He has more than 50 years of experience and was awarded the John Jaeger Memorial Medal for Contributions to Geomechanics in 1995.

Graeme Bell has been a Consulting Dam Engineer since 1962. His role has varied from providing the full technical input, design management and construction advice for new dams to the preparation of complex structural analyses of existing dams. From 1979, he has acted as an independent reviewer on many dam projects, mainly in Australia, but also in several overseas locations.

Mark Foster has 20 years of experience in dam engineering and geotechnical engineering. This has involved a wide variety of projects including dam safety reviews, design of dam upgrade projects and dam safety risk assessments for embankment and concrete dams. He has a particular interest in the assessment of piping and internal erosion of embankment dams which was the topic of his doctoral research studies at the University of New South Wales.