Two-stage calculations are made in buildings with basements. For the subdivision elements, the first and second stage calculation results are used by combining them properly.
In the case of calculations with the mode combination method, ductile internal forces, ie bending moment, normal force, etc. For internal forces, the internal forces obtained in the first loading state and the internal forces obtained in the second loading state are added together, and the internal forces essential to the design are obtained.
In case of calculation with Mode Combination method, for non-ductile internal forces, ie shear forces, the internal forces obtained in the first loading condition are multiplied by 0.6 * D top , the internal forces obtained from the second loading case are multiplied by D bottom and the two results are added.