NUMERICAL ASSESSMENT OF THE LATERAL STIFFNESS OF UNREINFORCED MASONRY RECTANGULAR COLUMNS

摘要

Using an efficient numerical model capable of capturing the cracking and second-order effects, this study investigates the lateral stiffness of unreinforced masonry rectangular columns at uncracked and cracked situations. The columns are modeled as prismatic cantilevers undergoing their own weights, eccentric vertical top loads, and static concentrated lateral top loads having increasing magnitude. The lateral force is considered to perform a monotonic lateral load analysis on the columns. On the basis of the numerically obtained lateral force versus lateral displacement relationships, the behavior of the columns is characterized by two limit states corresponding to the first cracking and the maximum resistance. For a reference column, the lateral stiffness values at these limit states are determined and compared with each other. The results show that the lateral stiffness of a column is related to the displacement level and hence the level of cracking. Implementing parametric analyses, the effects of some parameters are also investigated such as the column slendemess, the magnitude and eccentricity of the vertical top load, the flexibility parameter, and the angle of tilt, if any, on the lateral stiffness of the columns.