STUDY ON SEISMIC PERFORMANCE OF DOUBLE-COLUMN ROCKING BENTS WITH ADDITIONAL BRACES UNDER NEAR-FIELD PULSE GROUND MOTIONS

To solve the issues of insufficient bearing and energy dissipation capacities of rocking bents, a double-column rocking bent structure with braces placed in chevron arrangement is developed in this study. The braces are pure energy dissipation ones or self-centering energy dissipation ones, installed between the cap beam and the foundation of the double-column rocking bent by connecting devices. To study the seismic performance of the double-column rocking bent structure with braces developed, its quasi-static analysis is carried out firstly. Taking the double-column cast-in-situ bent and the double-column rocking bent as the comparative model, the hysteretic behavior of the double-column rocking bent with additional braces are investigated; The dynamic time history analysis of these bents is carried out to explore the dynamic responses of the structures due to the near-field symmetrical pulse, to near-field asymmetrical pulse and to far-field non pulse ground motions. These results show that: the double-column rocking bent with additional braces still behaviors the rocking mechanism, which can effectively avoid the serious damage to the plastic hinge of column; at the same time, the additional braces can significantly improve the bearing capacity and energy dissipation capacity of the bent and, reduce the displacement response of the bent; especially, the self-centering energy dissipation braces can also provide additional self-centering force for the bent, which can effectively improve the seismic performance of the bent.