Simplified mechanics-based approach for modeling of flexurally dominated reinforced masonry structural wall systems subjected to lateral load

Abstract

This paper presents a simplified analytical approach for modeling the behavior of both individual reinforced masonry structural walls (RMSWs) (component level) and systems of RMSWs as the main lateral load resistance system (LLRS) (system level) under lateral loading. Analytical modeling of individual RMSWs, with different end configurations (rectangular, flanged & end-confined), was achieved by generating the load-displacement relationships for these walls based on simple mechanics and accounting for plastic hinging. Knowing that plastic hinging is concentrated at the base of cantilever structural wall, its value was estimated based on experimental results and plasticity theory, taking into consideration the effect of strain penetration inside concrete foundation, inclined flexural-shear cracking and variation of curvature profile following yielding. Also, analytical modeling of a system of RMSWs may be conducted and the displacement of each wall can be calculated by simple geometrical relations, if the displacement of the center of mass (CM) and the rotation angle of the building are known. Results of some experimental tests were used to verify the results of the developed analytical models for individual RMSWs. The maximum error obtained in all models at maximum load, deformation at maximum load and deformation at 80% strength degradation, compared to experimental results, were 8.05%, 8.55% and 9.87% respectively. A third-scale building composed of several RMSWs as its main LLRS was used to verify the developed analytical algorithm for a system of RMSWs and the results showed that the value of building resistance was lower than the average value between push and pull cycles from experimental results by 7.38%. The analytical algorithms developed for both individual RMSWs and systems of RMSWs throughout this study were simply relying on analytical application program. As a result, better understanding of the behavior of systems of RMSWs when subjected to seismic loads can be achieved. The factors affecting the accuracy of the developed modeling technique are presented and discussed in this paper. Recommendations for problems faced through developing this modeling technique and the governing factors are presented throughout this study. Based on the analytical verification presented, a parametric study was carried out to investigate the effect of different parameters as lateral load eccentricity, torsional effects, and presence of walls orthogonal to the loading direction.