Lateral load-deformation models for seismic analysis and performance-based design of confined masonry walls

Abstract

Confined Masonry (CM) has been implemented as an affordable building type in many earthquake-prone regions and continuously gaining popularity all over the world. This is primarily because of the better performance exhibited by these buildings during past earthquakes, even though their design and construction methodology is much simpler, compared to other common housing typologies, like unreinforced masonry buildings and infilled reinforced concrete frame buildings. Though several experimental studies have been carried out on CM walls across the world, the variation associated with material properties, detailing of tie-elements, construction practices, etc., are huge. This makes the formulation of generalized analytical backbone models for CM walls a difficult task for an approximate prediction of their lateral load response. Existing empirical models for the prediction of lateral stiffness, strength, and deformability at different performance levels of CM walls are utilized in the present study to estimate these parameters for seventy-eight CM specimens tested in past studies. Analytical backbone profiles for CM walls are developed using these parameters. The experimentally obtained backbone parameters are compared with those estimated analytically from different empirical models to evaluate their effectiveness. Based on these observations, proposals are made for a generalized analytical backbone model of CM walls that may be used for performance-based seismic analysis and design.