Simplified density indexes of walls and tie-columns for confined masonry buildings in seismic zones

This paper discusses and quantifies the minimum requirements of walls and tie-columns in confined masonry (CM) buildings located in earthquake-prone regions. A research database including 238 damaged CM buildings obtained from the 2008 Wenchuan earthquake survey is established and comprehensively examined. The requirements of masonry walls in CM buildings are discussed, and a simplified tie-column density index is proposed for evaluating the potential damage of the structures. Besides, the minimum requirements of reinforced concrete tie-columns and their maximum allowable spacing in CM buildings at different seismic intensity zones are discussed.