In-plane and out-of-plane seismic performance and damage evaluation of reinforced concrete shear wall structures subjected to mainshock-aftershock sequences

The aim of this study was to examine the seismic performance of reinforced concrete shear walls in in-plane and out-of-plane directions under single main shock and mainshock-aftershock sequences. Two shear wall specimens were designed for low cycle load tests to withstand in-plane, in-plane then out-of-plane (IP-OP), out-plane, and out-of-plane then in-plane (OP-IP) forces, respectively. The seismic performance of shear walls under different forces was assessed by analyzing macroscopic failure phenomena and the novel performance parameters of specimens, following which their damage status was evaluated. The specimens were simulated using finite element software, and two frame shear wall structural systems were designed so that non-linear time history analysis could be performed to assess the deformation and damage to the shear walls in the two directions of the plane under a single main impact and different input directions of mainshock-aftershock sequences. The results revealed that following damage in the in-plane direction of the shear wall, seismic capacity decreased significantly if it was subjected to a force in the out-of-plane direction once again, and the degree of damage under the earthquake action of mainshock-aftershock sequences was significantly higher than that under the single main shock action. Therefore, it is necessary to pay special attention to the seismic performance of the out-of-plane direction of the shear walls and examine the seismic performance of the structural system under different input directions of mainshock-aftershock sequences.