Two-stage calculations are made in buildings with basements. First stage calculation results are used for upper section elements.
In the case of calculations with the mode combination method, ductile internal forces, ie bending moment, normal force, etc. For internal forces, in the first loading condition , the internal forces obtained in the upper section are directly used as the internal forces based on the design.
In case of calculation with the Mode Combination method, it is obtained by multiplying the internal forces obtained in the upper section with the top D in the case of the first loading for non-ductile internal forces, ie shear forces .