In the buildings designed with strong column weak beam concept, the columns will remain elastic, their plastic deformation will be limited. but this is not true at the base of the building. i mean i understand why at the base of building earthquake force is largest but why do we let plastic deformation there?
A building designed by the seismic code will resist the seismic spectra with no structural damage. There may be some minor damage to partitions or furniture banging around.
However, the code provides for extra ductility in the structure to be flexible enough under an exceptionally strong earthquake greater than design spectra to deform in a way that alerts the occupants of eminent danger and provides time for them to vacate.
Depending on the use of the building this design parameter varies and the amount of acceptable damages becomes smaller.
Such that in hospitals and critical buildings sometimes the columns are insulated from the foundation by hydraulic rollers or other means. Allowing the building to float on the foundation escaping the ground's shakes to a large extent.