Effect of SMA Restrainer on Seismic Response of Railway Self-centering Pier.

In order to study the influence of shape memory alloy (SMA) on the seismic response of railway self-centering piers, the SMA restrainer element is added to the verified two-spring model. Taking a railway bridge pier as the engineering background, the numerical analysis model is established based on OpenSees platform. By inputting three strong earthquake records, the influence of SMA restrainer on the pier is analyzed by nonlinear time history analysis method. The influence of the initial clearance and the change of the initial prestress of the key parameters of the SMA restrainer device on the displacement of the pier top and the bending moment of the pier bottom is discussed, and compared with the prestressed reinforcement restrainer. The results show that under ordinary ground motion El-Centro and Taft waves, the displacement at the top of the self-centering pier decreases with the decrease of the initial gap δ of the restrainer device, and the bending moment at the bottom of the pier increases with the decrease of the initial gap δ. With the increase of the initial preload of the SMA restrainer, the displacement of the top of the self-centering pier decreases and the bending moment of the bottom of the pier increases. The influence of SMA restrainer on the seismic response of self-centering piers under near-fault ground motion Northridge is complex. Under three strong earthquake records, compared with the prestressed reinforcement restrainer, SMA restrainer will reduce the bending moment of the pier bottom and increase the horizontal displacement of the pier top. [ABSTRACT FROM AUTHOR]