Theory 04/Earthquake Engineering
Damage Is a Period Ratio
The claim
Building damage in an earthquake is set by the ratio of the building's period to the site's period rather than by peak ground acceleration.
01Mechanism
A structure amplifies motion when its natural period matches the site; the same acceleration produces very different demands depending on the ratio.
02Predictions
- P1Damage should peak at a period ratio of one.
- P2Acceleration alone should mispredict across sites.
03Refutation
Damage tracking acceleration would remove the resonance ratio.