Performance Study of Single Helix Embedded in Cohesionless Soil Under Pull-Out Load

Abstract

In this investigation, an endeavour is made to understand the pull-out behaviour of single helix anchor embedded in cohesion less deposit. Physical tests were conducted using a laboratory-scale model tests tank of size 800 mm × 800 mm × 800 mm. A total of 18 tests were conducted in laboratory in which helix anchor was installed in loose and medium dense dry sand. A single model helix anchor made of steel was subjected to vertical pull-out load in a test tank with dry sand. Various parameters like diameter of helix were varied as 75 mm, 100 mm and 125 mm, embedment ratio was varied as 2, 4, 6 and relative density of sand was varied as 30 and 60% to understand their influence on the pull-out behaviour. A series of load uplift curves were drawn to understand the pull-out behaviour. It was observed that the pull-out capacity significantly varied with embedment ratio as well as the diameter of helix. But the increase in uplift capacity of helix anchor is less affected by increase in relative density in comparison to diameter of helix as well as embedment ratio. The results of the experimental investigation were validated using a numerical study based on PLAXIS 2D software. When the uplift load was varied with displacement from the PLAXIS examinations demonstrated commonly great concurrence with the physical modelling acquired from the exploratory outcomes.KeywordsCohesionless depositDisplacement contoursEmbedment ratioHelix anchorPLAXIS 2DPull-out loadUplift