Seismic Damage Assessment Indexes for Masonry Structures

Abstract

This paper proposes a new model to quantify the enhancement effect of confinement elements on the seismic behavior of confined masonry (CM) structures. Using this model, a combined assessment index considering the effects of material strength and the confinement elements on the seismic performance of masonry structures is developed to assess the potential damage of the structures subjected to seismic loads. A field survey of the Wenchuan earthquake is used to calibrate the proposed index and traditional wall density index. The relationship between the two indexes and the damage categories of unreinforced masonry (URM) and CM structures at different seismic intensity zones is discussed. Results show that the two indexes both predict the damage of CM and URM structures well, while the proposed combined index is verified with a better prediction accuracy. Using the two indexes, a complete assessment procedure is proposed for predicting the damage of the URM and CM structures at VIII to X seismic intensity zones. Case studies of two CM buildings at different seismic intensity zones are conducted to explain how to use the proposed assessment procedure and verify its feasibility.