Lapped-steel effects on bridge pier behavior under moderate near-fault motions

Abstract

Extensive research for the Far Fault Ground Motion (FFGM) has been carried out in strong seismic regions, but limited research has been done for the Near Fault Ground Motion (NFGM) because of very few records. Shake table tests for NFGM were conducted to investigate the seismic behavior of Reinforced Concrete (RC) bridge columns with lap-spliced longitudinal bars that are designed in low or moderate seismic region. Seven RC column specimens with a height of 1400 mm (55.2 in) and a diameter of 400 mm (15.8 in) were tested on a shaking table, and one alike specimen was quasi-statically tested. The effect on lap-spliced longitudinal reinforcing steel was investigated. Shaking test results are compared to those of the quasi-static test. The displacement ductility was significantly decreased in RC column specimens with lap-spliced longitudinal reinforcing bars. The effect of NFGM is compared to that of FFGM. The NFGM specimen showed somewhat less seismic capacity than the FFGM model from Fig. 4(d). Decrease of displacement ductility and energy dissipation was observed in the shake table test specimens in comparison with the quasi-static model.