Official website for Helical Piles: A Practical Guide to Design and Installation (Wiley Publishing, NY, 2009).
Written by Howard A. Perko, Ph.D., PE curriculum vitae.
Helical piles have risen from being merely an interesting alternative for special cases to a frequently requested, widely accepted deep foundation adopted into the 2009 International Building Code. The first and only 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 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. Chapters include:
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
Helical piles are a valuable component in the geotechnical tool belt. From an engineering/architecture standpoint, they can be adapted to support many different types of structures with a number of problematic subsurface conditions. From an owner/developer standpoint, their rapid installation often can result in overall cost savings. From a contractor perspective, they are safe and capacity can be verified to a high degree of certainty. From the public perspective, they are perhaps one of the most interesting, innovative, and environmentally friendly deep foundation solutions available today.
Definition
What is a helical pile? Helical piles are manufactured steel foundations that are rotated into the ground to support structures. The basic components of a helical pile include the lead, extensions, helical bearing plates, and pile cap.
Invention
When was a helical pile invented? The first recorded use of a helical pile was in 1836 by Alexander Mitchell, a civil engineer from Ireland, whom was, incidentally, blind from the age of 6. One of the problems that puzzled Mitchell was how to better found marine structures on weak soils such as sand reefs, mudflats, and river estuary banks. At the age of 52, Mitchell devised a solution to this problem, the helical pile.
Patents
Is the helical pile patented? There are more than 160 U.S. Patents for different devices and methods related to helical piles (see Appendix C and Chapter 15 of Helical Piles). A majority of early patents were for ship moorings, lighthouses, and marine structures. The period from 1875 to 1920, involve fencing and agriculture applications. From 1920 until about 1985, most patents regard guy anchors, tower legs, utility enclosures, pipelines, and other industrial applications. The modern era, beginning in about 1985, shows helical pile patents generally regarding underpinning and foundations for residential and commercial buildings.
Covering such issues of concern as environmental sustainability, Helical Piles provides contractors, architects, engineers, and students in civil engineering with a practical, real-world guide to the design and installation of helical piles.
About the Author:
Howard A. Perko, Ph.D., PE
Fort Collins, CO
Director of Engineering for Magnum Piering, Inc.
Past President of Structural Engineering, CTL|Thompson, Inc.
Board of Trusties, Deep Foundation Institute
Adjunct Professor, Colorado State University
Founder and Past President of The Secure Engineering Companies
Chairman, 2007 Deep Foundation Institute Annual Convention
NASA Jet Propulsion Laboratory Graduate Student Fellow
Academy of Civil Engineers, Michigan Technological University