Analysis of Vertical Piles Embedded in Organic Soil under Oblique Pull-Out Load

Abstract

Experiments regarding single model piles embedded in organic soil were conducted to determine the effect of pile type and soil density on ultimate pile oblique pull-out loads. Wood, steel, and smooth as well as rough concrete piles with diameters of 20 mm and embedment lengths of 200, 400, and 600 mm (length-to-diameter ratio L/D of 10, 20, and 30) were examined. The pull load was applied at an inclination of 0°, 30°, 60°, and 90° to the vertical axis of the pile. For each inclination angle, ultimate pull-out capacity was determined from load-displacement curves. Test results indicate that ultimate pull-out capacity increased with an increase in L/D ratio. While there was an increase in the pull-out load resistance of wood, steel, and smooth concrete piles when the angle of load inclination increased, there was a decrease in the pull-out load resistance of rough concrete piles when the load inclination angle exceeded 30°. Moreover, ultimate load capacity decreased when soil density decreased. Lateral pull-out capacity exceeded the axial uplift capacity of the steel, wood, and smooth concrete piles, and there was a slight increase in the ultimate load capacity of the rough concrete pile. The ultimate resistance of the piles was calculated theoretically via a semiempirical method and compared with test results. A comparison of the measured and predicted values indicated reasonable agreement pertaining to rough concrete piles and a disconnect regarding the other piles.