APPLICATION OF SMA FOR VIBRATION CONTROL OF ARAILWAY BRIDGE

A railway bridge, connecting major transportation routes, is a key node in transportation network. It must continue to function after an earthquake. Therefore, a higher level of performance with less structural damage is expected for such bridges. Recent earthquakes have demonstrated the importance of maintaining the operation of bridge structures. For railway bridges, seismic isolation bearings seismic which usually replace conventional bearings are used as protective systems. Despite benefit of this seismic retrofit means, excessive deck displacement during strong ground motions may result in unrecovered deformation and considerable damage to abutments. Hence, it is important to investigate the effectiveness of various protective systems in reducing response quantities of railway bridges. This paper presents a simulation-based control study in which shape memory alloy (SMA) restraining are proposed to control the seismic response of a seismically excited railway bridge with isolation bearings. The SMA restraining device is a passive control device employing superelastic Ni-Ti alloy wires as re-centering component, which restrains the bridge from excessive displacement responses, especially under extreme earthquake events. The results of this study show that the proposed passive control device can effectively reduce the excessive displacement responses and permanent bearing deformations of the base-isolated bridge subjected to strong ground motions.

کلیدواژه ها:

Shape Memory Alloy ، Seismic Retrofitting ، Bridges ، Nonlinear Time-History ، Izadkhast Bridge