How to Check the 25% Rule for Dual Systems in ETABS / SAP2000 | Staged Construction Analysis

Here is how to quickly and accurately check the 25% dual system requirement from ASCE 7-16 §12.2.5.1 in ETABS. We’ll review the code provision, explain why physically deleting walls can give inaccurate results, and walk through a staged construction method that keeps the gravity system intact while removing the shear walls from the lateral system. Watch to see the difference in deformation between the full model and the frame-only 25% case. The purpose of the 25% rule is to provide a secondary seismic force-resisting system with higher degrees of redundancy and ductility to improve the ability of the building to support the service loads (or at least the effect of gravity loads) after strong earthquake shaking. If you found this useful, like and subscribe to support the channel. Thanks! #ETABS #ASCE7 #StructuralEngineering #SeismicDesign #DualSystem #MomentFrame #ShearWall