Helical anchors have
found increasingly
widespread use in the
geotechnical market. These
foundation systems have the
advantages of rapid
installation, immediate
loading capabilities and cost
efficiency compared to
concrete piers and driven
piles. Over the years, helical
anchors have evolved from the
utility industry to the
foundation and earth retaining
construction market. Recent
developments and research
have granted the rapid
development of rational
geotechnical engineeringbased
design and analysis
procedures that can be used to
provide helical anchor design
solutions.
Introduction

Modern Usage

Modern helical anchors are
constructed of helical shaped
circular steel plates welded to
a steel shaft. The plates are
constructed as a helix with a
carefully controlled pitch.
The anchors can have more
than one helix located at
appropriate spacing on the
shaft. The central shaft is
used to transmit torque during
installation and to transfer
axial loads to the helical
plates. The central shaft also
provides a major component
of the resistance to lateral
loading.
These anchors are rotary
advanced into the
ground until the
appropriate bearing stratum is
reached or until the applied
torque value is obtained.
Extensions are added to the
central steel shaft as needed.
The applied loads may be
tensile (uplift), compressive
(bearing), shear (lateral), or
some combination.