68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

ESTIMATION OF UPLIFT SHAFT FRICTION FOR A SINGLE PILE IN EXPANSIVE SOIL USING THE MECHANICS OF UNSATURATED SOILS

Session: Foundations III / Fondations III

Yunlong Liu, University of Ottawa (Canada)
Sai Vanapalli, University of Ottawa (Canada)

Pile foundations that are installed in unsaturated expansive soils are subjected to uplift forces along the pile shaft due to the swelling of the expansive soils upon infiltration. This leads to the redistribution of the pile axial force and possible upward movement of the pile body. For this reason, it is necessary to take into account of uplift shaft friction by determining or estimating the uplift shaft friction along the shaft in the rational design of piles in expansive soils considering the influence of lateral swelling pressure. In this paper, the conventional ß method for calculating pile lateral friction is modified to estimate the uplift shaft friction for a single pile in expansive soils upon infiltration considering the influence of lateral swelling pressure and matric suction. The proposed method is successfully validated using the experimental data by Fan (2007).