ATTENTION: ASSIGNMENT DESKS

11/01/00
Contact: Parshaw Vaziri (510) 231-9550 vaziri@peer.berkeley.edu

A shaking table test of a 12-foot tall reinforced concrete bridge column to see how it withstands the severe ground motions that occur near an earthquake fault. The test on the nation's largest shake table at the University of California, Berkeley, will simulate a 7.5 magnitude quake and show Caltrans engineers how well current designs respond to near-fault ground motion.

BACKGROUND: Ground motions near earthquake faults are different - and often much more severe - than shaking at a distance. PEER and Caltrans are collaborating on tests to assess the performance of current bridge designs when subjected to such severe ground motions. The tests will help confirm current design methods and, if needed, areas of improvement. These results also will help validate and improve computer simulation tools for predicting earthquake response of major bridges.

The 12-foot tall test specimen is a one-sixth scale model of a type of column used in many new bridges, such as those replacing the Cypress Viaduct that collapsed in Oakland during the Oct. 17, 1989 Loma Prieta earthquake. The test column, which supports a large concrete block representing the bridge roadway and weighing more than 60,000 pounds, will be subjected to ground shaking recorded less that a mile from the epicenter of the 1978 Tabas-e-Golshan, Iran, quake - the largest earthquake ever recorded. This quake was far bigger than the 1994 Northridge (6.7) and the Loma Prieta (6.9) quakes. The Tabas quake resulted in widespread damage and more than 20,000 deaths.

DIRECTIONS: The Richmond Field Station is approximately six miles northwest of UC Berkeley. For detailed directions, go to the Web site http://eehsl.berkeley.edu/rfs.html