API Clay

The American Petroleum Institute (2002) defines the strength for a driven pile in clay as follows:

• Undrained Shear Strength - The shear strength of a material where pore pressures do not or do not significantly dissipate during the analysis period.
• Remolded Shear Strength - The shear strength of a material within a hollow pile that has been altered from its in-situ condition. Typically, this material is significantly weaker than the surrounding in-situ material.
• Maximum Unit Skin Friction - The maximum allowable unit skin friction that can be computed in the soil layer. The restriction is to prevent an overestimate of skin friction, especially for thick soil layers.
• Maximum Unit End Bearing Resistance - The maximum allowable unit end bearing resistance that can be computed in the soil layer. The restriction is to prevent an overestimate of the end bearing resistance, especially for thick soil layers.

API Clay Skin Friction (t-z) Load Transfer Curve

API Sand and Clay End Bearing (Q-z) Load Transfer Curve

For more information, see the Axial Analysis Theory Manual.