Skip to main content

Helical Piles: A Practical Guide to Design and Installation




Helical Piles: A Practical Guide to Design and Installation

Howard A. Perko

ISBN: 978-0-470-40479-9 October 2009 528 Pages


An unbiased, comprehensive review of helical pile technology and applications

Helical piles have risen from being merely an interesting alternative for special cases to a frequently requested, more widely accepted deep foundation adopted into the 2009 International Building Code. The first alternative to manufacturer-produced manuals, Howard Perko's Helical Piles: A Practical Guide to Design and Installation answers the industry's need for an unbiased and universally applicable text dedicated to the design and installation of helical piles, helical piers, screw piles, and torque anchors.

Fully compliant with ICC-Evaluation Services, Inc., Acceptance Criteria for Helical Foundation Systems and Devices (AC358), this comprehensive reference guides construction professionals to manufactured helical pile systems and technology, providing objective insights into the benefits of helical pile foundations over driven or cast foundation systems, and recommending applications where appropriate. After introducing the reader to the basic features, terminology, history, and modern applications of helical pile technology, chapters discuss:

  • Installation and basic geotechnics

  • Bearing and pullout capacity

  • Capacity verification through torque

  • Axial load testing, reliability, and sizing

  • Expansive soil and lateral load resistance

  • Corrosion and life expectancy

  • Foundation, earth retention, and underpinning systems

  • Foundation economics

  • Select proprietary systems

  • IBC and NYC Building codes

Covering such issues of concern as environmental sustainability, Helical Piles provides contractors and engineers as well as students in civil engineering with a practical, real-world guide to the design and installation of helical piles.




Chapter 1 Introduction.

1.1 Basic Features.

1.2 Terminology.

1.3 Invention.

1.4 Early U.S. Patents.

1.5 Periods of Use.

1.6 Modern Applications.

1.7 Environmental Sustainability.

Chapter 2 Installation.

2.1 Equipment.

2.2 General Procedures.

2.3 Special Procedures.

2.4 Installation Safety.

2.5 Torque Measurement.

2.6 Torque Calibrations.

2.7 Field Inspection.

Chapter 3 Basic Geotechnics.

3.1 Subsurface Exploration.

3.2 Field Penetration Resistance.

3.3 Soil Classification.

3.4 Bedrock.

3.5 Site Suitability.

3.6 Shear Strength.

Chapter 4 Bearing Capacity.

4.1 Helix Spacing.

4.2 Individual Bearing Method.

4.3 Cylindrical Shear Method.

4.4 Limit State Analysis.

4.5 Shaft Adhesion.

4.6 LCPC Method.

4.7 Pile Deflection.

4.8 Simple Buckling.

4.9 Advanced Buckling.

4.10 Down Drag.

Chapter 5 Pullout Capacity.

5.1 Theoretical Capacity.

5.2 Minimum Embedment.

5.3 Effect of Groundwater.

5.4 Group Efficiency.

5.5 Structural Capacity.

5.6 Cyclic Loading.

Chapter 6 Capacity-to-Torque Ratio.

6.1 Early Empirical Work.

6.2 New Emperical Justification.

6.3 Energy Model.

6.4 Simple Shaft Friction Model.

6.5 Other Theoretical Methods.

6.6 Precautions.

6.7 Exploration with Helical Pile.

Chapter 7 Axial Load Testing.

7.1 Compression.

7.2 Tension.

7.3 Loading Procedures.

7.4 Interpretation of Results.

7.5 Other Interpretations.

Chapter 8 Reliability and Sizing.

8.1 Factor of Safety.

8.2 Helix Sizing.

8.3 Computer-Aided Sizing.

8.4 Statistics.

8.5 Field Adjustments.

8.6 Reliability.

Chapter 9 Expansive Soil Resistance.

9.1 Expansive Soils.

9.2 Foundations on Expansive Soils.

9.3 Active Zone.

9.4 Pile Design.

9.5 Early Refusal Condition.

Chapter 10 Lateral Load Resistance.

10.1 Rigid Pile Analysis.

10.2 Flexible Pile Analysis.

10.3 Pile Groups.

10.4 Effect of Helical Bearing Plates.

10.5 Effect of Couplings.

10.6 Lateral Load Tests.

10.7 Emperical Results.

10.8 Lateral Restraining Systems.

10.9 Seismic Resistance.

Chapter 11 Corrosion and Life Expectancy.

11.1 Corrosion Basics.

11.2 Galvanic Corrosion.

11.3 Zinc Coatings.

11.4 Passivity.

11.5 Powder Coating.

11.6 Design Life.

11.7 Sacrificial Anodes.

11.8 Special Topics.

Chapter 12 Foundation Systems.

12.1 Basic Foundation Plan.

12.2 Foundation Loads.

12.3 Pile Cap Design.

12.4 Manufactured Pile Caps.

12.5 Bridges and Boardwalks.

12.6 Concreteless Design.

12.7 Lateral Bracing.

Chapter 13 Earth Retention Systems.

13.1 Lateral Earth Pressure.

13.2 Retaining Walls.

13.3 Excavation Shoring.

13.4 Timber Lagging.

13.5 Helical Soil Nails.

13.6 Grading and Drainage.

13.7 Post-Tensioning.

13.8 Wall Repair.

Chapter 14 Underpinning Systems.

14.1 Foundation Repair.

14.2 Underpinning Brackets.

14.3 Rotational Bracing.

14.4 Floor Slab Support.

14.5 Braced Excavations.

Chapter 15 Economics.

15.1 Cost and Availability.

15.2 Foundation Economics.

15.3 Measurement and Payment.

Chapter 16 Proprietary Systems.

16.1 Grouting Systems.

16.2 Ground Anchors.

16.3 Special Helix Shapes.

16.4 Underpinning Systems.

16.5 Enhanced Lateral Resistance.

16.6 Composite Piles.

16.7 Special Couplings.

16.8 Future Development.

Chapter 17 Building Codes.

17.1 IBC 2006.

17.2 IBC 2009.

17.3 Product Evaluation Reports.

17.4 AC358 Criteria Development.

17.5 New Evaluation Criteria.

17.6 Forthcoming Codes.

Appendix A. Common Symbols and Abbreviations.

Appendix B. Summary of Prior Art.

Appendix C. Load Tests Results.

Appendix D. Nomenclature.

Glossary of Terms.