Design of structures to resist earthquakes is motivating and challenging. The potential for damage is significant, and ground motions are as uncertain as building responses are complex.
Seismic design procedures are categorized as force-based and displacement- based.
The distinction is made to emphasize that an earthquake can be seen as imposing forces or displacements on the structure.
The force-based approach has the longest tradition, perhaps because most other hazards, like gravity, wind, and snow, are treated as imposed forces. As a result, the force-based approach is adopted in most building codes. The focus on displacements is more recent, with growing merit in seismic design because displacements seem to be more correlated with actual damage.
