SEISMIC REINFORCEMENT OF EXISTING CYLINDRICAL STEEL PIERS BY TAKING ADVANTAGE OF CONTACT EFFECT OF ADDED STIFFENERS

为了抗震加固既有桥墩，通常只要求提高其延性，同时抑制任何过度的承载能力加强。在本研究中，我们提出并验证了一种新的方法，这是，不同于传统的方法提供纵向加劲肋，相同的加劲肋提供给现有的圆柱形钢桥墩，同时精心允许之间的加劲肋的底部和桥墩的底板轻微的间隙。通过试验和数值分析验证了所估计的地震效应。研究表明，只有在地震力达到最大值后，加劲肋底部与桥墩底板接触才能有效地提高延性。

In order to seismically strengthen existing bridge piers, it is commonly required to improve only their ductility while suppressing any excessive strengthening of load bearing capacity. In the present study, we proposed and verified a new method, which is, unlike the conventional method of providing longitudinal stiffeners, the same stiffeners are provided to existing cylindrical steel piers while elaborately allowing a slight gap in between the bottom of a stiffener and bottom plate of a pier. The estimated seismic effect has been verified by an experiment and the numerical analysis. Our studies showed that only the ductility has been effectively increased by being contacted the bottom of stiffeners and the bottom plate of piers after seismic force has reached a maximum level.