Observations of the performance of buildings during the 1985 Mexico earthquake,and structural design implications

Summary The high amplification of the 1985 Mexico City earthquake is explained by the large number of strong and nearly continuous cycles of 2 s period motion lasting for more than 30 s. The type of damage caused by the earthquake—particularly to engineered multi-storey buildings of high flexibility is described, and methods of adding damping and stiffness elements to reduce and resist earthquake demand forces are discussed.