Seismic Behavior of a Concrete Rocking Wall with Controllable SMA Dampers: Concept and Experimental Evaluation

To reduce the structural damage in mainshocks–aftershocks and improve the repair speed after a mainshock, two types of controllable shape memory alloy (SMA) dampers (CSDs) with different configurations based on the specific thermomechanical properties of shape memory alloys and a novel rocking wall system with CSDs (RWCSD) were proposed in this paper. Five quasi-static tests were successively conducted on the rocking wall specimen to evaluate the seismic performance of RWCSD under multiple earthquakes. The test results showed that the specimen maintained relatively stable self-centering and deformation capacity. Simultaneously, the crystallin forms change of the SMA core in dampers effectively compensated for the performance degradation caused by mainshock, and the strengthening effect of CSDs on the structural strength was obvious. The RWCSD possessed the function of strengthening structural load-carrying capacity under aftershocks, which suggested the systematic design methodology was appropriate for further research.