The Earthquake Engineering Online Archive

Earthquake simulator testing of a base-isolated bridge deck

Kelly, James M.; Buckle, Ian G.; Tsai, Hsiang-Chuan

UCB/EERC-85/09, Earthquake Engineering Research Center, University of California, Berkeley, 1986-01, 111 pages (530/K38/1985)

In a series of tests carried out on the shaking table at U.C. Berkeley's Earthquake Engineering Research Center, a base-isolated bridge deck model representing a typical highway bridge superstructure was subjected to a variety of earthquake inputs representing both real and artificially generated earthquake signals. Two different forms of isolation system were tested, one using natural rubber elastomeric layers reinforced by steel plates and the other using the same bearings but with a lead plug inserted in a central hole. Results of these tests are described and responses of the bridge deck when carried on each system are compared. A simple analysis of the limit state of an isolation bearing is described and results of tests carried out to verify the analysis are presented. A parametric identification routine, designed to provide an equivalent linearization of the dynamic response of the nonlinear isolation system, was developed to provide elementary design rules for preliminary design of base-isolated buildings and bridges. The time histories of the equivalent linear systems are compared with the actual model to verify the accuracy of the method.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-85-09.pdf (7 MB)