Dynamic analysis of uniform and variable buildings with flexible base: Inclusion of local shear deformation of walls

Pinto-Cruz M.C. · Engineering Structures (2025) · DOI: 10.1016/j.engstruct.2024.119588

Resumen

The dynamic analysis of buildings using continuous models has been extensively studied in the literature; however, the mechanism of local shear deformation of the walls has been overlooked, leading to unconservative structural errors when the length of the walls is significant. Therefore, this article employs the generalized sandwich-type continuous beam to propose both analytical and numerical solutions for calculating the dynamic properties of the building. The continuous beam results from the series coupling of the classical sandwich beam and the shear beam, allowing (unlike classical continuous models) an adequate representation of the four types of mechanisms associated with the building's lateral motion: global bending, global shear, local bending, and local shear, including rotational inertias and soil flexibility. The closed-form analytical method addresses the particular case of buildings with uniform geometric and material properties along their height, while the numerical method employs a 6 × 6 transfer matrix (regardless of the number of discretizations) to solve buildings with variable properties along their height at a reduced computational cost. The proposed methods are validated through the dynamic analysis of a coupled shear wall, demonstrating that the continuous model used provides better accuracy compared to classical models and an excellent match with the finite element method. Furthermore, it is observed that the continuous model can accurately represent the behavior in bending, shear, and their interaction. It is verified that the influence of rotational inertia is negligible for the first mode of vibration and significantly affects higher modes. An exhaustive parametric analysis of 1525 cases are conducted to determine the validity range of the continuous model and its solution methods, showing that the continuous model allows for better accuracy, with a maximum error of + 7.37 %. Additionally, the study of the influence of soil flexibility reveals that, unlike previous studies, for low-rise buildings with significant wall length founded on flexible soils, the vibration periods decrease by up to −39.76 %, indicating that designs for such buildings are not conservative when assuming a rigid soil.

Instituciones: Universidad Nacional de Ingeniería