Evaluation of the seismic performance of prestressed precast coupled walls with friction coupling beams: experiments and theoretical behaviors

Abstract

The improvement of seismic toughness is one of research focuses on coupled shear walls. In this paper, a prestressed precast coupled wall with friction coupling beams (PPCW-FCB) was assembled, in which the prestressed tendons mainly provided lateral resistance and self-centering capability, and the friction coupling beams (FCB) provided energy dissipation capacity. Based on the quasi-static tests of three specimens, the effects of FCBs on the deformation characteristics and seismic performance of PPCW-FCBs were analyzed. The test results showed that after three loadings, only small cracks appeared within the height of the bottom FCB; the friction pads suffered from streak abrasion, but there was no obvious plastic deformation on the bolts and hole wall in the steel plate of FCBs, which was conducive to rapid repair after an earthquake. The FCBs were beneficial to improving the load and seismic performance of prestressed precast coupled walls. In detail, compared with the specimen without FCBs, the initial stiffness and load capacity of PPCW-FCB specimens increased by 196 % and 61 % on average, respectively; the equivalent viscous damping ratio and relative energy dissipation ratio increased by 266 % and 249 % on average, respectively. Based on the key performance points of gap opening, friction start, design state and ultimate state, a theoretical skeleton curve for the load-drift response of PPCW-FCBs was established. The theoretical skeleton curve formed a good envelope for the experimental load-drift responses, where the average deviation between the experimental and theoretical results at design state was only 6.6 %.