Table Of ContentCRC_52500_index.qxd 1/30/2007 4:41 PM Page 324
Geologic Hazards
A Field Guide for Geotechnical Engineers
CRC_52500_index.qxd 1/30/2007 4:41 PM Page 324
CRC_52500_index.qxd 1/30/2007 4:41 PM Page 324
Geologic Hazards
A Field Guide for Geotechnical Engineers
Roy E. Hunt, P.E., P.G.
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This material was previously published in Geotechnical Engineering Investigations Handbook, Second Edition © 2005 by
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Library of Congress Cataloging‑in‑Publication Data
Hunt, Roy E.
Geologic hazards : a field guide for geotechnical engineers / by Roy E. Hunt.
p. cm.
Includes bibliographical references and index.
ISBN 1‑4200‑5250‑0 (alk. paper)
1. Engineering geology‑‑Handbooks, manuals, etc. 2. Natural disasters. I. Title.
TA705.H844 2006
363.34’9‑‑dc22 2006052993
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Contents
Author ..............................................................................................................................................ix
Introduction ....................................................................................................................................1
Chapter 1 Landslides and Other Slope Failures................................................................3
1.1 Introduction............................................................................................................................3
1.1.1 General........................................................................................................................3
1.1.2 Hazard Recognition..................................................................................................4
1.1.3 Rating the Hazard and the Risk ............................................................................9
1.1.4 Elements of Slope Stability....................................................................................11
1.2 Slope Failure Form Characteristics ..................................................................................18
1.2.1 Creep ........................................................................................................................18
1.2.2 Falls ..........................................................................................................................19
1.2.3 Planar Slides in Rock Masses................................................................................20
1.2.4 Rotational Slides in Rock ......................................................................................27
1.2.5 Rotational Slides in Soils........................................................................................27
1.2.6 Lateral Spreading and Progressive Failure ........................................................29
1.2.7 Debris Slides............................................................................................................45
1.2.8 Debris Avalanches..................................................................................................47
1.2.9 Debris Flows............................................................................................................52
1.2.10 Rock-Fragment Flows............................................................................................52
1.2.11 Soil and Mud Flows................................................................................................53
1.2.12 Seafloor Instability..................................................................................................57
1.3 Assessment of Slopes..........................................................................................................59
1.3.1 General......................................................................................................................59
1.3.2 Stability Analysis: ABrief Review........................................................................59
1.3.3 Slope Characteristics..............................................................................................76
1.3.4 Weather Factors ......................................................................................................87
1.3.5 Hazard Maps and Risk Assessment....................................................................90
1.4 Treatment of Slopes ............................................................................................................92
1.4.1 General Concepts....................................................................................................92
1.4.2 Changing Slope Geometry....................................................................................97
1.4.3 Surface Water Control..........................................................................................101
1.4.4 Internal Seepage Control ....................................................................................102
1.4.5 Side-Hill Fills ........................................................................................................106
1.4.6 Retention................................................................................................................108
1.5 Investigation: AReview....................................................................................................117
1.5.1 General....................................................................................................................117
1.5.2 Regional and Total Slope Studies ......................................................................123
1.5.3 Detailed Study of Cut, Fill, or Failure Area......................................................126
1.5.4 Case Study ............................................................................................................127
1.5.5 Instrumentation and Monitoring........................................................................130
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References ....................................................................................................................................132
Further Reading ..........................................................................................................................135
Chapter 2 Ground Subsidence, Collapse, and Heave ..................................................137
2.1 Introduction........................................................................................................................137
2.1.1 General....................................................................................................................137
2.1.2 The Hazards ..........................................................................................................137
2.1.3 Scope and Objectives............................................................................................137
2.2 Groundwater and Oil Extraction....................................................................................138
2.2.1 Subsurface Effects ................................................................................................138
2.2.2 Surface Effects........................................................................................................139
2.2.3 Physiographic Occurrence ..................................................................................140
2.2.4 Significant Examples............................................................................................141
2.2.5 Subsidence Prevention and Control..................................................................144
2.3 Subsurface Mining ............................................................................................................148
2.3.1 Subsidence Occurrence........................................................................................148
2.3.2 Longwall Panel Extraction..................................................................................151
2.3.3 Room and Pillar Method (Also “Breast and Heading” Method)..................152
2.3.4 Strength Properties of Coal ................................................................................155
2.3.5 Investigation of Existing Mines..........................................................................156
2.3.6 Subsidence Prevention and Control and Foundation Support......................159
2.4 Solution of Rock ................................................................................................................160
2.4.1 General....................................................................................................................160
2.4.2 Solution Phenomenon and Development ........................................................160
2.4.3 Investigation..........................................................................................................165
2.4.4 Support of Surface Structures ............................................................................168
2.5 Soil Subsidence and Collapse..........................................................................................169
2.5.1 General....................................................................................................................169
2.5.2 Collapsible or Metastable Soils ..........................................................................169
2.5.3 Predicting Collapse Potential..............................................................................176
2.5.4 Treatment and Support of Structures................................................................178
2.5.5 Piping Soils and Dispersive Clays......................................................................180
2.6 Heave in Soil and Rock ....................................................................................................183
2.6.1 General....................................................................................................................183
2.6.2 Swelling in Soils....................................................................................................184
2.6.3 Swelling in Rock Masses......................................................................................187
2.6.4 Treatments to Prevent or Minimize Swelling and Heave..............................190
References ....................................................................................................................................191
Further Reading ..........................................................................................................................195
Chapter 3 Earthquakes........................................................................................................197
3.1 Introduction........................................................................................................................197
3.1.1 General....................................................................................................................197
3.1.2 Geographic Distribution......................................................................................198
3.1.3 Objectives and Scope............................................................................................203
3.2 Earthquake Elements........................................................................................................203
3.2.1 The Source..............................................................................................................203
3.2.2 Seismic Waves........................................................................................................206
3.2.3 Ground Motion......................................................................................................209
3.2.4 Intensity and Magnitude ....................................................................................214
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3.2.5 Attenuation............................................................................................................220
3.2.6 Amplification ........................................................................................................223
3.2.7 Duration ................................................................................................................227
3.2.8 Recurrence and Forecasting................................................................................228
3.3 Surface Effects on the Geologic Environment ..............................................................233
3.3.1 Faulting..................................................................................................................233
3.3.2 Soil Behavior..........................................................................................................245
3.3.3 Subsidence and Liquefaction..............................................................................248
3.3.4 Slope Failures........................................................................................................255
3.3.5 Tsunamis and Seiches: Response of Large Water Bodies................................260
3.3.6 The Volcano Hazard ............................................................................................262
3.4 Earthquake-Resistant Design: An Overview ................................................................263
3.4.1 Introduction ..........................................................................................................263
3.4.2 Structural Response..............................................................................................265
3.4.3 Site Ground-Response Factors............................................................................269
3.4.4 Response Spectra..................................................................................................271
3.4.5 Seismic Hazard Analysis ....................................................................................274
3.4.6 The Design Earthquake........................................................................................276
3.4.7 Soil-Structure Interaction (SSI) Analysis ..........................................................282
3.5 Investigation: Important Structures in High-Hazard Areas ......................................287
3.5.1 Introduction ..........................................................................................................287
3.5.2 Preliminary Phase ................................................................................................287
3.5.3 Detailed Study of Regional and Local Geologic Conditions..........................290
3.5.4 Evaluation and Analysis......................................................................................292
3.5.5 Limitations in the Present State of the Art........................................................293
References ....................................................................................................................................295
Further Reading ..........................................................................................................................299
Appendix The Earth and Geologic History ......................................................................301
A.1 Significance to the Engineer ............................................................................................301
A.2 The Earth ............................................................................................................................301
A.2.1 General....................................................................................................................301
A.2.2 Cross Section..........................................................................................................301
A.3 Global Tectonics ................................................................................................................302
A.3.1 General....................................................................................................................302
A.3.2 The Hypotheses ....................................................................................................302
A.4 Geologic History................................................................................................................303
A.4.1 North America: Provides a General Illustration..............................................303
A.4.2 Radiometric Dating..............................................................................................306
References ....................................................................................................................................307
Further Reading ..........................................................................................................................307
Index ............................................................................................................................................309
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Author
Now in private practice, Roy E. Hunt, P.E., P.G., has more than 50 years of experience in
geo-technical and geological engineering. Hunt has been an adjunct professor of engineer-
ing geology at the Graduate School of Civil Engineering, Drexel University, and currently
holds a similar position in the Geosciences Program at the University of Pennsylvania. He
has been the consultant on two new nuclear power plants in Brazil; a toll road program in
Indonesia and a new airbase in Israel; offshore mooring structures in the Philippines and
Brazil; and on landslide studies in Bolivia, Brazil, Ecuador, Indonesia, Puerto Rico, and the
continental United States. Assignments have also taken him to Barbados, England, France,
the U.S. Virgin Islands, and locations throughout the continental United States. His past
affiliations include Joseph S. Ward and Associates, where he was a partner, and Woodward-
Clyde Consultants, where he was director of engineering in the Pennsylvania office.
His education includes an M.A. in soil mechanics and foundation engineering, Columbia
University, New York (1956), and a B.S. in geology and physics, Upsala College, East
Orange, New Jersey (1952). He is a registered professional engineer in New Jersey, New
York, and Pennsylvania; a registered professional geologist in Delaware, Pennsylvania, and
Brazil; and a certified professional geologist. His professional affiliations include the
American Society of Civil Engineers (Life Member), Association of Engineering Geologists,
and the American Institute of Professional Geologists. He has received the E.B. Burwell Jr.
Memorial Award, Geologic Society of America, Engineering Geology Division, and the
Claire P. Holdredge Award, Association of Engineering Geologists, for his book Geotechnical
Engineering Investigation Manual (1984); and the Claire P. Holdredge Award, Association of
Engineering Geologists, for his book Geotechnical Engineering Techniques and Practices
(1986) —both books were published by McGraw-Hill, New York.
