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Studies on the Effect of Differential Motions of Two Foundations Upon the Response of the Superstructure of a Bridge.
Abdel-Ghaffar, A. M.
National Science Foundation, Washington, D.C.; Geological Survey, Reston, Va., January 1977, 96 p.
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This report contains two studies that were made of the effects of differential motion of the foundations upon the response of the superstructure of a bridge. The first study deals with the dynamic response of a 'long beam' model of a bridge to both steady-state and random excitations applied at the supports. The harmonic and random end-excitations were analyzed in the frequency and time domains, respectively. The second study develops a method to analyze the dynamic soil-bridge interaction of a simple two-dimensional bridge model erected on an elastic half-space, with the input motion in the form of incident plane SH-waves. The bridge model consists of an elastic shear girder supported by two rigid abutments and rigid foundations which have a circular cross section and which are welded to the half-space. Finally, the dynamic response of the bridge and the effect of the radiative damping in the half-space on the interaction of the bridge are also studied.
Dynamic response; Earthquake engineering; Random vibration; Highway bridges; Soil dynamics; Soil structure interactions; Girder bridges; Earthquakes; Dynamic structural analysis