Hi, The raft foundation bearing coefficient can be entered as zero, considering that the structure is only carried by piles... Since you will define the soil layers to make a pile solution, the program will take the stiffness of the springs to be modeled along the pile from the soil layers. There may be many differences between a project solved by entering the bed coefficient and a project solution with a zero bed coefficient; You assume that the structure is carried with rafts and piles. Since you will make a solution with superstructure-foundation interaction in piled foundations, the column-beam-panel etc. carrier system will also be affected by the result and the quantity will also change. Good work