SSI in RMBridge

The client request us on consideration of foundation/structure interaction in full bridge model. Please be asked how can I model of soil-structure model as for Soil Structure Interaction analysis(SSI) by directly model in RMBridge without using of Openbridge Modeler(OBD). I understand that if the model generated by OBD and transfer to RM can do that but that is not our look for since some limitation.

Thanks in advance.

WinaiG