The effective section stiffness of the reinforced concrete structural system elements   is taken into account by using  the effective section stiffness factors given in Table 4.2 , as   described in  Section 4.5.8 of TBDY . Effective cross-section stiffness factors are  applied  only  in the calculations under the loads included in earthquake effect Load Combinations (Combinations) and that fall into these load combinations according to  Article 4.5.8.3 of TBDY . Effective cross-section stiffness multipliers are not used in the calculation under loads included in load combinations that do not contain earthquake effect.


The constant load and live load effects, from which internal forces and displacements are obtained, calculated using the effective cross-section stiffness factors, are  represented by symbols G '  and  Q' in combinations  . Effective cross-section stiffness multipliers are not used in load combinations without seismic effects. In this case, the constant load and live load effects, from which internal forces and displacements are obtained, calculated without using the effective cross-section stiffness multipliers,  are shown with symbols G  and  Q in combinations  . Earthquake effects are taken into account using effective cross-section stiffness factors and the results of the analysis made using these factors in load combinations are taken into account.