Predicted and Measured Compressive Capacity and Torque of Large Helix Diameter Screw Piles in Stiff to Very Stiff Cohesive Soils

Gustavo Padros, Bien Dinh, Baocheng Li, Richard Schmidt

In the proceedings of: GeoManitoba 2012: 65th Canadian Geotechnical Conference

Session: M1B - Foundations I

ABSTRACT: Based on the results of 11 pile load tests, a comparison is carried out between the predicted and the measured compressive capacity of screw piles installed in stiff to very stiff cohesive soils. The predicted compressive capacity of screw piles was determined based on equations included in the Canadian Foundation Engineering Manual, applying a reduction to the undrained shear strength of the soil to take into consideration soil disturbance due to pile installation. The screw pile compressive capacity interpreted from the pile load tests was defined as the compressive loading that produced a pile displacement equal to 5% of the helix diameter. The comparison of the predicted and interpreted compressive capacities indicated satisfactory agreement for design purposes. Situations that may have influenced the pile load tests are described and the ratio between the torque applied during installation and the pile compressive capacity is discussed in terms of an empirical correlation.

RÉSUMÉ: Tenant compte les résultats des essais en charge de 11 pieus à vis, une comparaison s'est éfectuée parmis la prédiction et la médition de la capacité de compression des pieus à vis installées dans des sols cohésifs rigides à très rigides. La capacité de compression des pieus à vis prédite fut determinée en base aux équations inclues dan le Manuel Canadien d'Ingénierie de Fondations, ayant apliqué une réduction à la force de cissaillement non drainée du sol pour prendre en considération le dérangement du sol causé par l'installation des pieus. La capacité de compression des pieus à vis interpretée à partir des essais de charge du pieu, fût définie comme le charge de compression qui cause le déplacement du pieu égale à un 5% du diamètre de l'hélice. La comparaison des capacités de compression prédites et interprétées ont rendu un accord satisfactoire pour des propos de dessin. De situations qui peuvent avoir influencée les essais de charge de pieu sont décrits, ainsi que le ratio parmis le vissage apliqué au cours de l'installation et la capacité de compression de pieu est discutée tant qu'une co-relation empirique.

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Cite this article:
Gustavo Padros; Bien Dinh; Baocheng Li; Richard Schmidt (2012) Predicted and Measured Compressive Capacity and Torque of Large Helix Diameter Screw Piles in Stiff to Very Stiff Cohesive Soils in GEO2012. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Paper124,author = Gustavo Padros; Bien Dinh; Baocheng Li; Richard Schmidt,title = Predicted and Measured Compressive Capacity and Torque of Large Helix Diameter Screw Piles in Stiff to Very Stiff Cohesive Soils,year = 2012}