Grasshopper/ Cross Section

Hello Everyone, I’m trying to mode a rigid frame bridge! I started modeling the Cross-section( it has different thicknesses ): make points then connect them with a line then a surface. and for the length of the bridge, I used the extrude command then connected to the structural command area. I did not give a thickness to it since I used the extrude command… the problem is when I put some loads on the surface from above it also goes for the surface below as you can see in the picture it is wrong how I model it or there is another problem?
Screenshot 2022-06-28 234418


Could you please show me how you defined the Area Load with grasshopper?
I would try to select the top area and use it for the load definition.

(Since I don’t know how you created the surface, here’s a simplified version)

Best regards
Frederik Höller
Your SOFiSTiK Support Team