Foundation-Base Resistance of Pile in Non-Uniform Undrained Soil

When the undrained soil is non-uniform and its cohesion varies with depth, the rate of change of cohesion with depth needs to be determined.

Factor Fz is introduced to the equation for this scenario. It can be determined from a chart developed after Davis and Booker (1973).

The shape factor is taken as 1.2 for square and circular pile section.