Push-over analysis of underground double columns with coupling beam in the isolation system of monolithic translation structure

After monolithic translation of superstructure, the upper structure and new foundation should be connected effectively. Installations of isolators between the topside structure and base are not only make full use of the translation material, but also enhance the security of the building. For the masonry structure of integral translation, double columns with coupling beam of the vertical bearing component are formed. Combined action of horizontal seismic and the vertical load can generate additional bending moment in this component. Finite element model is set up according to the characteristic of double columns and coupling beam based on the Buyukozuturk elasto-plastic constitutive model in MSC.Marc. A method that can balance the additional moment is proposed. Before and after this moment is applied, Stress and strain of FEM at the ultimate state are contrasted, and influence to the Push-over curve of the additional moment is put forward. It is shown that this method could quantitatively analysis the P-Δ effects in the vertical components, and implement simply.