Seismic behavior of an innovative equivalent monolithic precast shear wall under low and high axial load ratios

Abstract

To meet the demands for the axial load and shear capacity of prefabricated reinforced concrete shear walls located at lower floors in high-rise buildings in high seismic intensity area, an innovative equivalent monolithic precast shear wall (labeled as EMPSW) was proposed by introducing X-shaped steel plate bracings and high ductility hidden column in this research. And seismic behavior of two EMPSWs under low and high axial load ratios (ALRs) were evaluated by quasi-static loading tests. The experimental phenomenon showed that EMPSWs under low and high ALRs presented similar fully developed and wide distributed cracks, whilst the ultimate draft ratios and ductility coefficients of specimens all met the specification requirements, exhibiting good lateral resistance through ductile damage for EMPSWs under different ALRs. Also, the increase of ALRs could improve the load carrying capacity and initial stiffness, but had no benefit on the energy dissipation and deformation capacity of EMPSW. Then, a reasonable strut-and-tie model (STM) was applied and verified to be well suitable for predicting the mechanical behavior of EMPSW. Besides, further investigations regarding the influence of critical parameters were implemented by finite element analysis (FEA). The FEA results illustrated that a higher ALR was beneficial for load-bearing capacity but had a significant negative impact on deformation capacity, thus the test ALR for EMPSW should be controlled within 0.5 in engineering practice. The volumetric ratio of X-shaped steel plate bracings and longitudinal reinforcement ratio in hidden column had a positive effect on capacity, but their contributions decreased as ALR increased.