Observations about the seismic response of RC buildings in Mexico City

Abstract

Over 2000 buildings were surveyed by members of the Colegio de Ingenieros (CICM) and Sociedad Mexicana de Ingenieria Estructural (SMIE) in Mexico City following the Puebla-Morelos Earthquake of 2017. This inventory of surveyed buildings included nearly 40 collapses and over 600 buildings deemed to have structural damage. Correlation of damage with peak ground acceleration (PGA), peak ground velocity (PGV), predominant spectral period, building location, and building properties including height, estimated stiffness, and presence of walls or retrofits was investigated for the surveyed buildings. The evidence available suggests that (1) ground motion intensity (PGV) drove the occurrence of damage and (2) buildings with more infill and stiff retrofit systems did better than other buildings.

Hyper‐reduced order models for accelerating parametric analyses on reinforced concrete structures subjected to earthquakes

“…As a result, only one‐dimensional (1D) nonlinear material laws were used, while shear and torsion remained elastic. The transverse steel reinforcements were also assumed to prevent shearing failure mechanisms since they were not explicitly included in the multi‐fiber mesh, even if experiments and post‐seismic inspections proved that such phenomena could also appear on short beams and columns as well as on column/beam connections subjected to cyclic loadings (Alcocer et al., 2020). A better modeling of concrete shearing could have been achieved using a 2D plane strain material law, even if modeling accurately shearing failure mechanisms still requires 3D finite elements linked to 1D steel reinforcements (Hervé‐Secourgeon et al., 2021), which was not addressed in this work.…”

“…As the amplitude of the cycles is higher with such ground motions, the strains increase, as well as the damage level. The PGV, computed by integrating the ground motion over time, is also a good indicator since high values refer to strong-intensity earthquakes that are more likely to cause significant damage (Alcocer et al, 2020). However, the PGD was not used here to select earthquakes, as it is more suited for tall structures (Lai et al, 2022).…”

The interpretation of cumulative damage from the building response observed in Mexico City during the 19 September 2017 earthquake

“…Frame buildings in the range of five to ten stories displayed the highest rate of damage or collapse in the 2017 earthquake (Alcocer et al, 2020; Berron, 2018). This range of stories corresponds to the period range of 1–1.5 s, which is also the range of the dominant periods of soils in which buildings had the highest rate of damage or collapse in the 2017 earthquake (see Figures 1 and 2).…”