Characterization and testing of the Caltrans Seismic Response Modification Device Test System

The California Department of Transportation (Caltrans) has recently commissioned a Seismic Response Modification Device (SRMD) Test System, housed in the Department of Structural Engineering at the University of California, San Diego. This facility is being used to test and characterize various isolation bearings, dampers and lockup devices scheduled for use in the seismic retrofits of several large California bridges. This stateoftheart, sixdegreeoffreedom seismic testing system incorporates many new concepts in earthquake simulation system design. The results of the initial shakedown characterization testing are presented, a model to predict the machine's inertial and frictional characteristics is developed, and the initial testing results of some SRMD isolation bearing specimens are presented.