Numerical Design-Analysis for Piles in Sands

A number of field load tests for piles in cohesionless soils are analyzed using the finite element method. Satisfactory correlations are obtained between numerical predictions and observations for pile movements versus applied load, and division of total load into point and skin friction components. Computed bearing capacities using various failure criteria show good agreement with those evaluated from a formula based on limit equilibrium and from field data. Distributions of normal and shear stresses along the pile wall, and coefficient of lateral earth pressure, and significance of stress paths in the stress-strain law are examined. Effects of diameter and length of embedment on bearing capacity, particularly at higher lengths of embedments, are found to differ from those given by the limit equilibrium formula. A modification in the formula is suggested to account for the reduction in bearing capacity with length of embedment.