Two slender reinforced concrete structural walls in each principal direction!
Reinforced concrete structural walls of rectangular cross- section constitute the most suitable bracing system against seismic actions for skeleton structures. The walls may be short in horizontal direction e.g. 3 to 6 m- they must extend over entire height of the building.
To minimise the effects of torsion, the walls should be placed symmetrically with respect to center of mass and as close as possible to the edges of the building.