Experimental Investigation on Seismic Performance of Tall RC Bridge Piers

Abstract:

Four tall reinforced concrete columns with box section were tested in static cycle loadings and multi-level performance was investigated. The entire progression of cracking was monitored by using clip-on gage and then residual cracking damage was explored. It shows that cracks measured after the specimen was totally re-centered following a displacement cycle would substantially underestimate residual crack damage. An extra discount on the strength demand could be obtained if allowing a tiny residual crack that requires no repair work. Concrete crushing and spalling were also investigated in the test, and similiar experimental results were selected from the PEER datebase and also from some literatures. The samples showed a well concentrated distribution in lateral drifts at the onset of concrete crushing, about 2.39 percent on average, which is quite consistent with the present tests. Finally, all the specimens were found failed from fracture of the longitudinal reinforcement. The equations proposed by Prestely and by Berry were compared in predicting of the ultimate displacement capacity, and the results show that the equation presented by Berry yielded better results for the specimens.

Key words:reinforced concrete; tall columns; seismic performance; residual crack; drift ratio