Shake-table tests, subjected to mainshock–aftershock sequences, were conducted on a 1/3-scaled 3-story steel frame equipped with self-centering viscous-hysteretic devices (SC-VHDs) and its primary frame to investigate the effect of the aftershock on seismic performance. It was found that the SC-VHD can effectively reduce 30%–50% of the peak drift and 50%–80% of the residual drift, respectively. Additionally, the peak and residual drifts of the 3-story primary frame under the mainshock–aftershock sequences were more than those under the mainshock-only sequences, while the peak and residual drifts of the 3-story SC-VHD frame under the mainshock-only and mainshock–aftershock sequences were basically the same. A numerical simulation method for the SC-VHD frame was further developed and validated, based on which 6-, 9-, and 12-story SC-VHD frames were analyzed to investigate the seismic performance of medium- high-rise SC-VHD frames. Both shake-table tests and numerical analysis indicate that the peak and residual drifts of the 3-, 6-, 9-, and 12-story SC-VHD frames can meet the design objective under the mainshock–aftershock sequences.

To improve the safety performance of important rooms, such as operating rooms and disaster command centers, during an earthquake, a novel partial seismic isolation system suitable for new and existing frame structures is proposed, and the seismic and optimization analysis is carried out. Using the finite element numerical simulation method, the models of the ordinary frame structure and the partial isolated system structures were established. Considering the seismic response of the isolation room, the design safety of the partial isolation room, and the seismic impact on the overall structure, this study analyzed the damping effect of the partial isolation system. We changed the type of isolation bearing, the location of the isolation room, and the load to further optimize the calculation of the seismic isolation structure. The results show that the new partial isolation system could significantly reduce the seismic response of the isolated room under the action of a magnitude-8 rare earthquake. The damping rate of the relative acceleration and relative displacement between the top and bottom of the columns of the isolated room could reach 90%. It was found that the partial seismic isolation system proposed in this paper was applicable to reinforced concrete frame structures and could significantly reduce the seismic response of the isolated rooms without affecting the seismic performance of the main building. This partial seismic isolation system is easy to construct, applicable to both existing and new structures, and provides a new and effective seismic mitigation measure to improve the seismic performance of locally important rooms in the structure.

A triple friction pendulum bearing (TFPB) as an isolator has been considered more competitive than conventional bearings such as rubber bearings or single friction pendulum bearings due to its versatile behaviors under different levels of earthquakes. However, as the seismic responses are reduced, the wind-induced responses of the building may increase simultaneously, and this phenomenon is more common for isolated high-rise buildings compared with midrise and low-rise structures. In this paper, an analytical model for an isolated high-rise building with TFPB and a magnetorheological (MR) damper is proposed. An optimal fuzzy logic controller (FLC) is further proposed based on the multiobjective method, so as to reduce the wind responses without diminishing the base-isolation effect. To evaluate the proposed controller, seismic and wind-induced responses of the building controlled by the optimal FLC are compared with those of the building using the human-designed FLC and the building without control. According to the numerical analyses, it is found that although wind-induced responses can be reduced by both controllers, the human-designed FLC may reduce the wind-induced responses at the expense of increased seismic responses (increased by 12% in average of maximum absolute accelerations), whereas the optimal FLC can reduce both the wind and seismic responses (the reduction of maximum absolute accelerations is no less than 48% and 9%, respectively).