Foundation-Interface Shear Strength of Pile in Drained Soil

In drained soil, the interface shear strength of pile is a function of pile roughness, soil properties and installation method.

The calculation method is often known as Beta-method. The coefficient Beta is the product of lateral earth pressure coefficient and the tangent of pile-soil interface friction angle.

The pile roughness is expressed in terms of asperities on its surface, and it is also influenced by the type of material. Studies from Uesugi & Kishida (1986), Uesugi et al. (1990), Subba Rao et al. (1998) and Frost et al. (2002) serve as a good reference in determining the parameter.

For undrained fine-grained soil, Beta can also be expressed as a function of yield stress ratio.