Collapse analysis of building structures under excitation of near‐fault ground motion with consideration of large deformation and displacement

The dynamic analysis of structural stability with consideration of material and geometrical non‐linearity is necessary for near fault‐earthquake that is rich in long‐period components and often induces the non‐linear large displacement and deformation response of a building structure. A macro‐element bilinear geometric stiffness model and simplified analytical model are proposed and developed to analyze the P‐Δ effects of structural dynamic response using a numerical approach. A structural stable threshold diagram is then proposed to evaluate the geometric stability of a building structure with large deformation under the excitation of a near‐fault earthquake. The analysis results reveal: (1) the simplified geometric stiffness analytical model is useful for analyzing structural dynamic P‐Δ effects and acquire very good accurate results even though the structural geometric stiffness varies between elastic and plastic zone; (2) stable threshold diagrams, based on dynamic analysis and statistical analysis procedures, are conducted by application of this proposed model to easily evaluate structural geometric stability with larger deformation imposed by a near‐fault earthquake. This method can supplement the insufficient capability for the static pushover analysis procedure to estimate the seismic proof demands for building without dynamic P‐Δ effects analysis; (3) the analysis results of stable threshold diagrams indicate that when stability coefficient θ of a building is greater than 1 or base shear factor (V/W) of the building is less than 0·2, static P‐Δ effects become noticeable. Copyright © 2007 John Wiley & Sons, Ltd.