Analytical parametric studies were performed on the vertical mixed structure intended for mid-rise buildings, to investigate the seismic behavior. Based on the results of the analysis, a method for rationalization of seismic design is proposed. Specifically, we focus on the ratio of the inverse of the inter-story deformation angles of the upper and lower part of the mixed structure. It is also confirmed that the load capacity is not required to be increased by the Fs value when the ratio of the inverse of the inter-story deformation angles is 15 or more.
