This book describes the geotechnical design, installation and application of helical anchors and piles in soils to civil engineering practice. A number of design examples and parametric analyses are presented illustrating the procedures for determining the ultimate axial tension and compression capacity of single-helix and multi-helix anchors and piles in clay and sand, illustrating basic design methods. Methods of installation are described and recommendations for installation monitoring are given. The behavior of groups of helical anchor and piles is also described. Examples of the use of helical anchors and piles for a wide range of applications in civil engineering construction are presented. Methods of load testing and interpretation of load test results are described. Examples are also given for calculating side resistance of steel and grouted central shafts.