Pile-Soil Interaction Properties

Pile-soil interaction properties allows for a connection between pile and soil. The soil interacts with piles (modelled by beam elements) through nodes along the piles in 3 dimensions $(x, y, z)$. At the base of the pile, the $z$ interaction is through normal bearing contact. Along the piles, $z$ interaction is through shearing contact between piles and soil. The normal and shearing interaction stresses are given by

$$\frac{\sigma}{\sigma_{ult}}=C\left(\frac{\delta}{D}\right)$$

for vertical shear interaction along the piles and

$$\frac{\sigma}{\sigma_{ult}}=C\left(\frac{\delta}{B}\right)$$

for horizontal normal contact interaction along the piles

where:

• $σ$ is the interaction stress (shear or normal as relevant),
• $σ_{ult}$ is the maximum value of the stress defined on this table,
• $C(\hspace{0.5em})$ a coefficient obtained from Pile-soil interaction coefficients/curves explained in Pile-soil interaction coefficients table,
• $δ$ is the relative displacement explained below
• $D$, $B$ are geometry parameters explained below.

The values of $δ$ represent the relative displacement between the pile and the elastic ground soil near it. That is, $δ$ is the nonlinear deformation of the soil local to the pile, which is usually behaving in a nonlinear manner.

For circular piles $D = Bx = By =$ the diameter of the pile

For rectangular piles, $B_x$ and $B_y$ are the side width of the rectangular section, $p = 2B_x + 2B_y$ and $D = p/π$

For H & I sections, $B_x$ is the flange width, $B_y$ the web height + 2 × flange thickness, $p$ the complete perimeter (roughly 2 × web height + 4 × flange) and D $= (2B_x + 2B_y)/π$.

Definition

Name

name of pile-soil interaction property.

Pile-Soil Interaction Curve (coefficients) in X, Y & Z or the curve used for pile base

These define the interaction curves used for x, y and z interaction and for the pile base interaction

The maximum soil bearing/shear stress-in X, Y, Z & pile base at both top and bottom of each layers of the soil.

These define maximum bearing/shear stresses in direction directions and locations