Citation

Singhal A, Tahiani C. Can. Geotech. J. 1969; 6(2): 177-195.

Copyright

(Copyright © 1969, National Research Council of Canada)

DOI

10.1139/t69-015

PMID

unavailable

Abstract

In this paper, the influence of the soil properties on the dynamic response of a building subjected to different earthquakes is quantitatively analyzed. The proposed mathematical model for foundation and surrounding soil consists of (1) an equivalent soil-foundation mass M0, (2) a translational spring of stiffness K0, (3) a rotational spring of stiffness Kθ, and (4) dashpots for damping in translational and rocking modes. By using existing theory, values for K0 and Kθ have been selected for a rigid foundation supported by semi-infinite soil mass. A numerical incremental-iterative type of scheme is devised and a linear acceleration method is utilized to obtain the elastic and inelastic structural response. Digitized earthquake records from El Centro 1934 and 1940 have been utilized to study the influence of foundation conditions on the structural response of a multi-storey building. A range of soil properties and soil damping characteristics are chosen and various response curves are presented; this leaves complete freedom to a soil and foundation engineer to choose any desired value of the soil properties.Numerical analyses of a three-storey building show that for the foundation, the largest relative displacement occurs in the translational mode and the largest foundation rotation can be obtained by combining translational and rotational modes. It is shown that the natural frequency for a building in which the foundation effects are considered is always lower than that obtained for a building in which foundation effects are neglected. It is found that the soil damping characteristics have a major influence on the structural response, but Poisson's ratio of the soil has a minor influence. Various other recommendations regarding earthquake foundation designs are also suggested.


Dans cet article, les auteurs étudient l'influence de plusieurs propriétés du sol, telles que le module d'élasticité, le coefficient de Poisson et l'amortissement sur la réponse dynamique des bâtiments soumis à des tremblements de terre. Le modèle mathématique proposé pour la fondation et le sol sous-jacent se compose (1) d'une masse équivalente M0, (2) d'un ressort de rigidité K0 pour la translation, (3) d'un ressort de rigidité Kθ pour la rotation et(4) d'amortisseurs pour la translation et la rotation. Les expressions analytiques de K0 et Kθ utilisées dans cette étude ont été établies par la théorie de l'élasticité pour des fondations rigides reposant sur un milieu semi-infini. Les équations d'équilibre dynamique sont résolues par la méthode itérative de l'accélération linéaire à l'aide d'un ordinateur. Les auteurs étudient la réponse d'un bâtiment à trois étages soumis aux tremblements de terre au moyen des accélérogrammes enregistrés à El Centro en 1934 et 1940. Les propriétés des sols sont choisies...

Language: en