Current procedures of analysis and seismic design of
structures are conducted considering elastic behavior. This consideration is
possible assuming that the seismic forces are lower than the corresponding ones
obtained from the elastic design spectrum prescribed by the seismic code. These
forces are computed Response Reduction Factors, which are determined according
the structural type, member’s constituent materials and the expected ductility
of the whole structure, among others.
Recently, a strong earthquake strike
Ecuador. A large number of buildings collapsed under the action of the ground
motion, thereby revealing some weakness in the construction process. This
article presents the results of a study on the calibration of the Response
Reduction Factors used for special moment resisting framed steel buildings,
prescribed by the current Ecuadorian Construction Code. To this end, a set of regular
buildings located in a high seismic hazard level zone, has been modelled and
analyzed using pseudo-static non-linear procedure. Results were processed
according two different methodologies, revealing that the code values prescribed
for the Response Reduction Factor overestimate the seismic response of designed
buildings, so they should be modified in order to guarantee the seismic safety
of new buildings.