For DTS = 4a, Mdev> = 0.75Mo must be provided.
The Complete Message:
The condition ∑Mdev> = 0.75Mo must be met in reinforced concrete structural systems with unidirectional gear floor with DTS = 1, 1a, 2, 2a, 3a or 4a.
The condition ∑Mdev / M0> = 0.75 must be met in reinforced concrete structural systems with unidirectional gear floor with earthquake design class (DTS) 4a.
According to article 22.214.171.124 of TBDY , ductility level should be provided in mixed structural systems (4.3).
∑ M DEV ≥ 0.75 M o (4.3)
Shearwall / shearwall group can be added to the structural system until the 4.3 condition is met.
Solution can be made by choosing high ductility level. ( A14 or A15 )
Different flooring type can be selected.
∑ M DEV = In reinforced concrete and steel composite structural systems, the sum of the tipping moments caused by earthquake loads at the base of the reinforced concrete walls with high ductility level bond beam (with or without gaps) and central, eccentric or buckling-prevented steel braced frames
M o = Total tipping moment at the base from earthquake loads for the entire building