Failure process of masonry buildings during earthquake and associated casualty risk evaluation

Abstract

Collapse of masonry structures during an earthquake is analyzed using the three-dimensional distinct element method (3D-DEM) code developed by the first author. The DEM is a numerical analysis technique, in which positions of elements are calculated by solving equations of motion step by step. Both individual and group behavior can be simulated. The structure is modeled as an assembly of distinct elements connected by virtual springs and dashpots, where elements come into contact. First, the validity of the developed 3D-DEM code is confirmed by comparing analytical results with static experimental results of masonry walls. Second, failure process of masonry buildings due to earthquake is investigated using DEM. Effects of reinforcing methods are also examined. Finally, injury to human bodies in the collapsing masonry buildings is also calculated. Assuming that occupants lie down on the floor, two types of casualty criteria are introduced and assessed.