UCSD Seismic Response Modification Device (SRMD) Test Facility

A ceremony was held August 16 at the Charles Lee Powell Structural Research Laboratories, University of California, San Diego (UCSD), to announce the new Seismic Response Modification Device (SRMD) test facility. This unique facility will allow the testing of full-scale devices, such as dampers and isolator bearings, that have recently been incorporated in many seismic retrofit strategies, particularly the Caltrans Toll Bridge Retrofit program. The capacities and sizes of these devices make problematic the characterization of their performance, longevity, and wear. The new dedicated testing facility, sponsored by Caltrans, is capable of real-time six-degree-of-freedom dynamic characterization of full-scale bearing devices and dampers.

The main technical capabilities of the system are reported in the following table.

Table







As visible in the plan view and the transverse cross section, the testing system consists of a prestressed concrete self-reacting frame and a moving platen, activated by four horizontal and eight vertical actuators.




































Longitudinal Cross Section Transverse Cross Section



The platen, 3.65 m wide and 4.87 m long, slides over four hydraulic hydrostatic low friction bearings attached to the floor of the concrete structure. The platen also extends, for improved stability, with four steel outrigger arms that support four low friction sliding actuators at their top. The testing system is completed by two additional reaction structures: a removable steel cross beam and a prestressed reaction wall on one end of the machine, designed for tests on dampers. The removable cross beam and the configuration of the platen make the system flexible to perform in different testing setups, with the characteristics of a shaking table.









Frieder Seible, Professor and Chair, Department of Structural Engineering (UCSD)

Professor André Filiatrault, Professor of Structural Engineering (UCSD)

Gianmario Benzoni, Senior Development Engineer (UCSD)

Dorie Mellon, Principal Engineer (Caltrans)