Shen W.-CHwang S.-JLi Y.-AWeng P.-WMoehle J.P.SHYH-JIANN HWANG2021-08-052021-08-0520218893241https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102475030&doi=10.14359%2f51728092&partnerID=40&md5=f1011ec878183fb507a4fc30dcc7f5e1https://scholars.lib.ntu.edu.tw/handle/123456789/576076Soft or weak stories are defined as stories in buildings that are more flexible or weaker than adjacent stories. These stories can be vulnerable to damage and collapse during strong earthquake ground shaking, especially when the story is supported by reinforced concrete columns susceptible to shear failure. To effectively evaluate and retrofit such buildings, it is necessary to clearly define the stiffness and strength behavior of the column. According to experimental observations, shear deformation and shear failure typically are concentrated in the end regions, or D-regions, of the column where stress concentrations occur. A method is proposed for defining the type of failure in the end region, its shear strength, and the corresponding lateral displacement. To facilitate engineers to perform nonlinear pushover analysis, a simple procedure is developed for defining the lateral force-displacement relationship for columns sustaining shear failure. The procedure includes shear deformations caused by shear crack expansion within the shear failure region. The proposed model is shown to produce lateral force-displacement relationships that compare favorably with experimental data. Copyright ? 2021, American Concrete Institute. All rights reserved.Concrete construction; D region; Professional aspects; Shear deformation; Force displacement; Ground-shaking; Lateral displacements; Non-linear pushover analysis; Reinforced concrete column; Shear critical; Strength behavior; Strong earthquakes; Reinforced concretejournal article10.14359/517280922-s2.0-85102475030