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

Abstract

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.

Keywords:

• Helical piles
• sand
• installation torque
• power
• friction angle
• unit weight of soil
• wing ratio

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Giovanni Spagnoli is currently working as a global project and technology manager for the Underground Construction for BASF Construction Solutions GmbH (Germany) and he conceived and designed the study, analyzed the data, wrote the article in whole, revised the article.

Carlos Mauricio Mendez Solarte is currently MSc student at the Politecnico di Torino (Italy) and he performed the calculations.

Cristina de Hollanda Cavalcanti Tsuha is a professor at the Department of Geotechnics at the University of São Paulo (Brazil) and she supervised the technical and scientific robustness of the models and revised the article.

Pierpaolo Oreste is a professor at the Department Environmental, Land and Infrastructural Engineering at the Politecnico di Torino (Italy) and he revised the article and the results.

Acknowledgments

The authors would like to thank Dr. Jose A. Schiavon for the installation data of the helical anchor models tested in his thesis and Dr. Mohammed Sakr for the friendly support during our review of his model.