What will be interface property

Question

I am concerned about the interface between the light green element and the violet element? 
 
 Light green element: soil material 
 Violet element: Volume element representing the retaining wall having concrete properties. 
 
 I have Rinter value for both light green soil element and violet concrete element. I have also clicked the option of interface from adjacent soil. So for interface properties, which value of Rinter will it take?

Dennis Waterman · Answer

Dear Piyush, 
 The interface is drawn at the "green side" of the line that separates the green and violet materials, so it will take the properties from the green material. If you would have applied a positive interface it would have been drawn on the "violet side" of the line and then it would have taken the properties from the violet material. 
 With kind regards, 
 Dennis Waterman