## 5 Final Remarks  
In recent years, with the observation of damage reported to buildings during earthquakes, research efforts have been devoted to studying the effect of the infill walls on the structural response of multi-story buildings, where the studies have confirmed that the  
Figure 12: Radar diagrams to compare the studied results in the four cases. **(a)** Study Case N°:1, **(b)** Study Case N°:2, **(c)** Study Case N°:3, **(d)** Study Case N°:4.  
presence of infill walls may affect or interfere with the behaviors of the construction system during an earthquake. However, even though a vast body of research has addressed the interactive behaviors between infill and RC frames, few studies have examined the effects of the irregular distribution of infill walls over the height of buildings. Therefore, it may be necessary to study the impact of this interference to find out the extent of its impact on the behaviors of the building when an earthquake occurs. This study aims to conduct an analytical study to verify the effect of the variability of the presence of infill walls on the behavior of these buildings on the lateral loads, and important results were drawn regarding the distribution of these walls in multi-story buildings, which may be better taken into consideration in the future. The main conclusions that can be drawn from this study can be summarized as follows:  
* The results of the pushover analysis show an increase in the initial stiffness and resistance capacity for the full infill frame compared to the bare frame, despite the brittle failure modes of the masonry wall. The presence of masonry walls has a significant effect on the observed collapse mechanism. * The size of the openings in the infill walls has a significant influence on the stiffness. Generally, it decreases as the size of the opening increases, indicating that the decrease in stiffness is more important than the decrease in mass. * The infill panels increase the lateral stiffness of the frames, the presence of openings reduces the lateral stiffness of the frame, and with the increase in the size of the openings, the deformation capacity increases; in general, the bare frame shows better ductility than the infill walls frame; this can be attributed to the brittle behavior of masonry infill panels. * It appears on the one hand that the masonry increases the lateral load-bearing capacity and reduces the deformation demand, which can reduce the damage in the structures; on the other hand, an irregular distribution of the masonry can result in the relatively fragile behavior of the structure. The failure modes of the bare frames are distributed over the height of the structures; in the case of the infilled frames, the failure modes are concentrated in the lower levels. * The infill walls distributed homogeneously over the entire height of the building, such as FF, or the alternating distribution over the entire height of the building leads (as an example: RF, MF), to an increase in the stiffness of the structural system, and thus, a decrease in the desired ductility in the disposal of the structure before reaching the collapse. * The ratio of the contribution of the infill walls affects the energy damping, as changing the distribution of the infill walls over the entire height of the building would increase the amount of energy absorbed by the buildings, by controlling the collapse mechanism associated with the shape of this distribution (how plastic hinges are formed). * The change in the distribution of infill walls, while maintaining their number in the building, has a major role in changing the percentage of building walls' contribution to bearing the base shear. * The change in the number of masonry infill walls in the building plays a major role in changing the values of the contribution ratio, as the percentage of the building walls' contribution to bearing the base shear increases with the increase in the number of masonry walls in the building.