Experimental and numerical investigation on the seismic behaviors of RC shear walls with multiple post-openings before and after strengthening by steel plates

In this paper, the quasi-static tests of seven RC shear walls and the corresponding finite element simulations were carried out to investigate the seismic behaviors of the RC shear walls with multiple post-openings before and after being strengthened by bonding steel plates, including failure modes, bearing capacities, ductility, energy dissipation capacities, structural performance levels, and also the strain distribution of the rebars. The detail arrangements of the post-construction openings are taken into account, on the premise of the same total area of the openings. Not only in the tests but also in the simulations, there is one RC wall with a single post-opening in the center of the wall, one RC wall with two post-openings that are horizontally arranged at the mid-height of the wall, and one RC wall with two post-openings which are vertically arranged at the mid-length of the wall. In addition, other three specimens, with the same opening arrangements as the three types of RC walls motioned above, strengthened by bonding steel plates around the openings, and one shear wall without openings for reference were fabricated. The results showed that the failure modes of reinforced or unreinforced RC shear walls with post-openings are shear failure and flexural shear failure respectively. The seismic bearing capacities of the shear walls with post-openings can be obviously recovered, up to 33.5%, by bonding steel plates. Moreover, the ductility coefficients of those strengthened RC walls were also improved, in the range of 5.6% to 58.1%.