CCEER-05-7: Near Fault (Near Field) Ground Motion Effects on Reinforced Concrete Bridge Columns

Abstract

Characteristics of near fault ground motions warrant special consideration due to their severe and impulsive effects on structures. These characteristics are unique compared to far field ground motions, which nearly all seismic design criteria are based on. The purpose of this preliminary study was to investigate near fault ground motion effects on reinforced concrete bridge columns and to provide a framework for the design of bridge columns that incorporate these effects.

Two large-scale columns were designed and tested under a near fault ground motion on a shake table at the University of Nevada, Reno. One column represented the current California Department of Transportation far field design and the other was based on the American Association of Highway and Transportation Officials provisions. The most unique response seen from both column tests was the relatively large residual displacements. Based on this finding, a framework for the design of RC bridge columns with respect to the control of residual displacement was established.