Abstract

RODRIGUEZ, Mario E.. Seismic-resistant design regulations for structures, earthquake and experimental results lessons. Ing. sísm [online]. 2023, n.110, pp.19-44.  Epub Feb 05, 2024. ISSN 0185-092X.  https://doi.org/10.18867/ris.110.611.

September 19, 1985, and September 19, 2017, earthquakes in Mexico City have shown that the seismic demands in these earthquakes exceeded those specified by Mexico City building codes. This study shows that these events are not unique cases and gives examples of several earthquakes worldwide in which seismic demands exceeded those set by building codes. This study illustrates limitations in current procedures for the seismic analysis of structures. Uncertainties in the assessment of design seismic demands and constraints in the seismic analysis of structural systems indicate that having the lateral strength specified by building codes is not enough and that structures must have lateral deformation capacity. It follows that structural systems with low or intermediate ductility, such as those allowed in the Mexico City Building Code (MCBC, 2017), would not be desirable for resisting strong earthquakes. The last part of this work shows computed story drifts in buildings with different structural systems, either based on frames or using structural walls. This study compares story drifts in these structural systems for both using the seismic demands specified by MCBC 2017 and for the seismic demands corresponding to the September 19, 2017, earthquake in Mexico City. Results for these story drifts show the importance of rigid structural systems for reducing story drift demands, not only for avoiding collapse in strong earthquakes but also for significantly reducing building damage.

Keywords : seismic design; seismic building codes; earthquakes; story drift; experimental results.