Performance of RC wall building subjected to earthqueake and tsunami in sequence

Chile is in one of the most seismically active areas in the world and due to its location and geography, strong ground motions are usually followed by large tsunamis. Thus, high density coastal cities in Chile are exposed not only toearthquakes but also to tsunamis.

Typically, residential buildings in Chile are medium-rise reinforced concrete (RC) wall buildings, which have shown adequate seismic behavior in the strong events of the last decade in terms of preventing collapse and protecting human life. Additionally, these buildings have shown adequate behavior after the latest tsunamis following the 2010 Maule earthquake and 2015 Illapel earthquake, were only non-structural damage was observed in first stories due to the tsunami action. Although there is a significant exposure of RC wall buildings to the sequential action of earthquake and tsunami, most of the research has been focused mainly on the seismic behavior of these structures. Little research has been found regarding the tsunami behavior of this type of buildings, and even less regarding the sequential action of both earthquake and tsunami. In order to understand the behavior of the typical Chilean residential buildings to both hazards, a real building is selected as a case study. Nonlinear finite element simulations of a representative slice of the building are performed using the software DIANA considering a double pushover analysis. The earthquake pushover is applied first until a specific damage state is reached and then the earthquake loading is removed. Then, the tsunami pushover is applied considering only the hydrodynamic forces of the wave through the variable depth pushover (VDPO) approach. Additional effects such as flooding at the back of the building, buoyancy, uplift and debris impact were neglected. A set of tsunami load cases are evaluated considering different loading directions and Froude numbers. Based on the results of this research, the main variables affecting the tsunami capacity of the building are analyzed, and the impact of the previous earthquake damage in the tsunami capacity of the building is discussed.