U.S. Geological Survey
Fact Sheet 068-03

CAPTURING BUILDING PERFORMANCE

The 1994 Northridge earthquake (magnitude 6.7) in southern California tested the structure that replaced the Olive View Hospital, which was heavily damaged by the 1971 San Fernando shock (see front page) and later razed. The replacement building was designed to be stronger than its predecessor and was instrumented by the California Geological Survey. During the 1994 shock, shaking sensors recorded horizontal acceleration of the ground that was nearly equal to the acceleration of gravity and horizontal acceleration at the roof level that was 2.3 times gravity (g). These motions are among the most severe yet recorded in and adjacent to an engineered structure during a quake. The new building suffered only minor structural damage and remained in operation except for a brief interruption due to a sprinkler-system rupture on the ground floor.

| MAIN TEXT |
| MONITORING ONSET OF STRUCTURAL DAMAGE | EVALUATING EARTHQUAKE PROTECTION |
|SHAKING IN AN IRREGULAR STRUCTURE | ASSESSING SAFETY | CAPTURING BUILDING PERFORMANCE |