Deformation response spectrum

[karthik_m]

Hey,

I am wondering why the deformation response is the same for buildings higher than 10 secs natural period of vibration. Anyone could help? Thank you

 

[Agent666]

Probably because most codes have a minimum base shear coefficient/seismic coefficient. At some point you design for a constant minimum level of lateral load to ensure there is some minimum level of capacity achieved and hence robustness against larger than design level seismic events (which is simply taken to be the most likely event based on probabilistic approaches, but does not preclude larger events from occurring)