Seismic behavior improvement of reinforced concrete shear wall buildings using multiple rocking systems

Abstract

In recent years, researchers have proposed damage avoidance design philosophy, instead of traditional design concept, which is inherently damage-oriented, to mitigate suffered damage of buildings. To this end, the rocking system which is a method for limiting seismic forces to structures along with energy dissipation devices and restoring force system have been well established. A considerable number of studies have been conducted to investigate the seismic performances of base-rocking systems on precast segmental bridge piers, shear wall, and steel braced frame. In recent years, a few works have investigated the multiple rocking system behavior; but, there are still vague points about the details and response of this system. Thus, different shear wall buildings (three cases of the rocking structure and one case with a traditional design and 8, 12, 16, and 20 stories) were analyzed under two suits of ground motions levels using precise model. The results demonstrated that, if energy dissipation and post-tensioning tools are implemented properly in the multiple rocking system, (a) higher mode effects are mitigated on shear and moment actions, (b) the drift ratios do not increase approximately compared to the result of traditional wall and get closer to the result of base rocking system, (c) the values of horizontal acceleration remains almost constant with the development of rocking sections over height, (d) residual displacements of buildings are negligible, (e) the centerline elongation of shear walls are not considerable; for taller buildings, they are smaller than shorter ones, and (f) the pounding at the contact surface is not important.