Parametric analysis for the estimation of the installation power for large helical piles in dry cohesionless soils

A parametric analysis was conducted to estimate the installation power for two helical piles with helix diameters of 0.6 and 0.45 m and a shaft of 0.3 m in dry cohesionless soils. After having compared three models with the installation power of eight helical piles in laboratory, 520 simulations have been performed with different friction angle values, unit weight of soils, different rounds per minute and constant helix thickness. The results show that the power increases with increasing unit weight of soil, friction angle and increasing RPM. Besides, by increasing the helix-to-shaft ratio from 1.5 to 2 the power increases of about 40%. Because the geometrical characteristics of the pile play alsoa role, by changing the helix-to-shaft ratio until 5, it was shown that if the helix diameter is kept constant, the installation power values decrease, whereas if the shaft diameter is kept constant, the installation power increases.