Composite damping ratio of seismically isolated regular bridges
Journal
Engineering Structures
Journal Volume
19
Journal Issue
1
Pages
55-62
Date Issued
1997
Author(s)
Abstract
In this paper seismically isolated regular bridges are modelled as two-degree-of-freedom systems in the longitudinal or transverse direction. The equivalent linear characteristics, including the effective stiffness and equivalent viscous damping ratio of isolation bearings, are used to formulate the equivalent linear theory of the seismically isolated regular bridge. The system composite damping ratio, attributed to the equivalent viscous damping ratio of isolation bearing and the viscous damping ratio of bridge column bents or piers, is obtained both by classical damping and nonclassical damping assumptions. The parametric influences including those of the mass ratio, stiffness ratio, viscous damping ratio of bridge column bents and equivalent viscous damping ratio of isolation bearings on the composite damping ratio are investigated. The composite damping ratio formulated in the study is compared with that obtained from the modal strain energy method. In addition, the parametric influences on the system composite damping ratio of isolated bridges are compared with those of isolated buildings. Copyright © 1996 Elsevier Science Ltd.
SDGs
Type
journal article