The Mexico Earthquake of September 19, 1985—Behavior of Steel Buildings

During the September 19, 1985 earthquake about 60 post-1957 multistory steel buildings in Mexico City were subjected to a severe test. In most cases, the damage in the post-1957 structures was minor to moderate. The notable exception is the Pino Suarez complex in which one 21-story building collapsed onto a 14-story building, and two other 21-story buildings were severely damaged. The behavior of these buildings as well as two other case studies are analyzed. Conclusions are drawn on the ductility demands imposed on steel buildings in Mexico City, utilizing simplified structural models and considering the actual strength of buildings that may be much higher than the code design strength.