Hello, Curtains are not modeled as shells. I suggest you model curtains as shells. The Bap curtains you enter in the basement are challenging your system. Therefore, the basic additional reinforcement areas are excessive. You can solve the problem by increasing the main reinforcement and basic additional reinforcements. In another method, if you have entered the baffles for the shelter and water tank, you can reduce the forces on the foundation by designing these baffles as sub-beams without connecting them to the system.