Eriksson Pile contains two unique interaction diagrams. One is the ultimate interaction diagram showing the ultimate capacity of the member. The second is the service interaction diagram which shows the service capacity of the member.
Ultimate Interaction Diagram
Eriksson Pile allows for the use of two different methods to calculate flexure strength for the Ultimate Interaction Diagram. These two methods are the Secant Method from the ACI Journal 1970, and the ACI Moment Magnification Method. Strain compatibility is used to find the flexure capacity of the member. The detailed methodology of this procedure can be found at Flexure Strength .
Service Interaction Diagram
The service interaction diagram was created based on elastic section analysis using gross cross-sectional properties of the member.