9 – Pile Settlement

Publisher Summary When a pile is loaded, two things happen—the pile settles into the soil and the pile material compresses due to the load. Soil settles by a distance of s. This settlement occurs for two reasons: shortening of the pile due to the load and settlement of surrounding soil. The settlement of single piles can be broken down into three distinct parts—settlement due to axial deformation, settlement at pile point, and settlement due to skin friction. Under ‘‘Load Distribution of Piles,’’ it is not easy to accurately compute the load distribution along the length of the pile. Skin friction acting on the sidewalls of the pile absorbs a certain percentage of the load. In some cases, skin friction is so paramount that very little load develops at the tip of the pile. Axial compression of the pile is directly linked to the load distribution of the pile. Because of the load transmitted at the pile tip, soil just under the pile tip could settle. Skin friction acting along the shaft may stress the surrounding soil. Skin friction acts in an upward direction along the pile. Equal and opposite force acts on the surrounding soil. The force due to pile on surrounding soil would be in a downward direction.