Report No.: CCEER-00-9

Title: Shake Table Testing of a 1960's Two Column Bent with Hinged Bases

Authors: J. Moore, D. Sanders, and M. Saiidi

Date: December 2000

Sponsoring Agency: Nevada Department of Transportation (NDOT)

Performing Organization:
Department of Civil Engineering/258
University of Nevada, Reno
Reno, NV 89557


This report describes the testing of a 0.3-scale as-build bent based on the average properties of six bridge bents in California. The prototype bents are characterized by a hinge detail at the bottom of the columns with insufficient development length of the hinge bars and minimal confinement along the length of the columns.

The model bent was dynamically tested using a series of increasing amplitudes of the Sylmar earthquake acceleration record, to a displacement ductility of 4.3. Observation of the tested model showed limited spalling of the columns and minimal cracking of the beam. Analytical analysis predicted the lateral load capacity of the bent, when the moment capacity of the hinge and bond slip were included in the dynamic model.

This test concluded that the prototype bridge bents would perform as desired in a seismic event, and no seismic retrofit is necessary for areas of low seismicity.