Stiffness of Subsoil Below the Pile Heel
The soil stiffness below the pile heel follows from the value of stiffness of the Winkler model C1. The value of C1 is determined for soil parameters Edef and ν at the location of pile heel. The value of C1 further depends on the depth of influence zone beneath the heel.
The spring stiffness introduced at the pile base is then provided by:
cross-sectional area at the pile heel