The Complete Message:
Structural system type A23 (in X / Y direction) is selected. Shearwalls should be used in A23 structural systems.
A23 bearing system is defined in the earthquake regulations as buildings where the moment-transferring ductility level of the earthquake impacts are met by single-direction geared reinforced concrete frames with or without filling (hollow blocks) and reinforced concrete walls with high ductility level bond beams (hollow).
However, the shearwall is not defined in the project.
Shearwalls should be added in the direction requested in accordance with the A23 structuralsystem in the project .
If shearwall will not be used in the building, A31 must be selected in the Analysis Settings / TBDY 2018 Earthquake Code Wizard. Bearing systems consisting of filled (filler) or unfilled single-direction geared reinforced concrete frames will be classified as structural systems with limited ductility level and will only be used in buildings with DTS = 3 and DTS = 4. (TBDY 18.104.22.168)