Performance Evaluation of Simple Regular Buildings using FBD and DDBD Methods with a Consistent Target Drift

The Direct Displacement Based Design (DDBD) method, proposed by
Priestley, is an alternative to the traditional Force-Based Design (FBD)
method for earthquake-resistant design. This study compares the
performance of 4-story and 12-story buildings designed using both FBD
and DDBD with the same target drift of 2%. The differences in base
shear used for the design of the two approaches are discussed. To
evaluate the buildings performance, Nonlinear Dynamic Procedure
(NDP) analysis, or nonlinear time history analysis, was conducted considering
500 and 2500 years return period earthquakes. The results indicate that
the actual drift of both designs deviates from the target drift; however,
the observed drifts remain within the maximum limits set by FEMA
356. Moreover, plastic damages were observed in unexpected areas of
the columns, suggesting that the strong-column weak-beam design concept,
as stipulated by building codes, does not entirely prevent damage to
columns.