Collapse of Eight‐Story RC Building during 1985 Chile Earthquake

Abstract

The behavior of an eight‐story, reinforced concrete apartment building that suffered severe structural damage during the 1985 Chile earthquake is investigated. A series of linear and limit analyses are described in an attempt to identify the cause of the collapse. The results indicate that global response parameters, such as base‐shear strength and mean drift ratio, are insufficient to explain the observed damage. The building had been designed with strength and stiffness characteristics comparable to other buildings that survived the earthquake with light to moderate damage. Investigation of the behavior of individual members leads to the conclusion that the building collapsed after the longitudinal reinforcement fractured in a first‐story wall. This form of brittleness is related to under‐ rather than overreinforcement. The observed failure and data from laboratory tests demonstrate that minimum amounts of longitudinal reinforcement should be established in seismic‐design requirements for structural walls.