Characteristics and ductility estimation of reinforced concrete walls in damaged buildings during 2010 CHile earthquake

Abstract

About 2% of Reinforced Concrete (RC) buildings taller than nine stories suffered important damage during 2010 Chile earthquake. The structural configuration of Chilean residential buildings is characterized by using a large number of RC walls, which provides high lateral stiffness. The characteristics of walls of five representative damaged buildings are summarized in this article in order explain the observed behavior. Characteristics of each wall include reinforcement ratios, axial load, wall thickness and M/Vl_w ratio. The ductility capacity of a selected wall was obtained from the moment-curvature relationship and its strength design was verified using the interaction diagram. This analysis confirms that the presence of high axial loads, combined with low wall thickness and poor reinforcement confinement is critical for the seismic performance of a single wall and of the whole building. Additionally, the provided ductility capacity of this wall was not consistent with the force reduction factor used in the design of the building.