Approximation of lateral stiffness for walls with two bands of openings considering slab stiffness effects

Abstract

Approximations obtained using the equivalent frame and equivalent shear connection methods to assess elastic lateral displacement profiles of walls with multiple openings per story are compared to results obtained with the finite element method using reasonably fine meshes. Multistory walls were studied, considering symmetric and asymmetric distributions of two openings per story with respect to a vertical axis. The contribution of slabs to lateral stiffness was considered through an equivalent flange, as recommended in the masonry guidelines of Mexican codes. Different stiffnesses are considered for the walls and slabs. An updated proposal is evaluated to define an equivalent opening from multiple openings per story. Results indicate that approximations obtained with the studied methods are improved as: a) multiple openings are more regular and symmetric, b) the opening size parameter is smaller, and c) the global slenderness ratio increases. The contribution from stiffness of the slab has an important impact for walls with typical door openings, but it is less important for walls with typical window openings, particularly if multiple window openings are symmetrically located and they form an equivalent coupling deep beam among them.