Lateral Loading of a Pile in Layered Soil Using the Strain Wedge Model

Beam on elastic foundation theory provides an efficient solution for the problem of a laterally loaded pile. The accuracy of such a solution depends upon the characterization of the interaction between the pile and the surrounding soil. A particularly good representation of the soil-pile interaction yields a more realistic solution. While traditional nonlinear “p-y” characterization provides reasonable assessment for a wide range of loaded piles, it has been found that the p-y curve (or the modulus of subgrade reaction) depends on pile properties (width, shape, bending stiffness, and pile-head conditions) as well as soil properties. The strain wedge model allows the assessment of the nonlinear p-y curve response of a laterally loaded pile based on the envisioned relationship between the three-dimensional response of a flexible pile in the soil to its one-dimensional beam on elastic foundation parameters. In addition, the strain wedge model employs stress-strain-strength behavior of the soil as established from the triaxial test and the effective stress condition to evaluate the mobilized soil behavior.