Cohesive

The following parameters are available for Cohesive soil layers:

• Undrained Shear Strength
• Modified Bearing Capacity Factor, N
• Adhesion Factor for Shaft
• Unit Cylindrical Shear Limit

Nc’ is Meyerhof’s (1951) modified bearing capacity factor.

The Adhesion Factor for Shaft is applied to unit skin calculations on shaft segments. To enable it for capacity calculations, ensure that Include Shaft Adhesion/Friction is enabled from the Capacity Calculations tab of the Project Settings.

The Unit Cylindrical Shear Limit provides an upper bound to the results of cylindrical shear and values shall not exceed this amount. The default value is set to 10000 so as to not preemptively cap the results at the limit.

If installation torque analysis is being performed on the helical pile, users can define Torque Parameters in the Define Installation Torque Parameters dialog. In this dialog users can define the Shaft Sizing Factor (𝝽ts) which is applied to the torque calculations of the shaft, and the Cylinder Shear Sizing Factor (𝝽tc) which is applied to the torque calculations of the soil cylinders between helices. 

Users can also define the following parameters for the Helical Plates: 

• Adhesion Factor for Helical Plates 
• Helix Sizing Factor (𝝽th)
• Pitch Sizing Factor (𝝽tp)

The Helix Sizing Factor (𝝽th) is applied to the torque calculations of the upper and lower faces of the helices, and the Pitch Sizing Factor (𝝽tp) is applied to calculation of the torque acting against the pitch of the helices.