Investigation on the behavior factor of leaning masonry wall structures

Abstract

In force-based seismic design, the behavior factor q (or response modification factor R) is devised to prevent overdesign by reducing the design force. Different values of the behavior factor q are available for various structure types. However, masonry fence walls are not categorized in the current seismic design codes. These walls are of poor quality due to the absence of proper quality assurance and maintenance, and most of those structures are inclined. In this study, the behavior factor q of leaning masonry fence walls is experimentally estimated. We fabricate three masonry wall structures that are inclined with three different wall angles of 1.5°, 3.0°, and 6.0°, respectively. Monotonically increasing biaxial lateral loads are applied to the walls using a shaking table. The value q of each leaning wall is calculated by analyzing the dynamic load-displacement relationship. A relationship between the factor q and wall angle is discussed, and a new empirical formula representing q as a function of a wall angle is proposed. The proposed empirical formula would be useful in seismic design for severely leaning masonry walls.