C-Phi

There is a checkbox for users to select if they want calculations within C-Phi soil to be done with Effective Stress Analysis. If unchecked, the calculations will be done using Total Stress Analysis. 

The following properties are available for C-Phi soil layers:

• Cohesion Intercept
• Adhesion Factor for Shaft
• Unit Cylindrical Shear Limit
• Angle of Internal Friction, Φ
• Angle of Friction Between Shaft and Soil, δ
• Overconsolidation Ratio (OCR)

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 the capacity analysis is being performed on the helical pile, users can define the Capacity Parameters in the Define Capacity Parameters dialog. In this dialog users can define the Coefficient of Lateral Earth Pressure acting on the Shaft and Cylinder Shear in Compression and Uplift separately as either:

• User Defined with a custom input

  

• At Rest

  

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 Coefficient of Lateral Earth Pressure acting on the Shaft and Cylinder Shear as either:

• User Defined with a custom input

  

• Passive

  

The Shaft Sizing Factor (𝝽ts) is applied to the torque calculations of the shaft, and the Cylinder Shear Sizing Factor (𝝽tc) is applied to the torque calculations of the soil cylinders between helices. 

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

• Angle of Friction Between Helix and Soil
• 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.