Structural Performance Assessment and Retrofit of Reinforced Concrete Buildings Under Seismic Loads

摘要

The study proposes a method utilizing 3D nonlinear dynamic analysis of buildings with the objective of achieving predictable seismic performance and building strengthening that translates to the owner's requirement. The frame model assumes that the nonlinear behaviour of the structure is concentrated in plastic hinges, modelled as spring system located at element ends. The nonlinear parameters of the spring systems are derived from the actual member section. The model is verified via agreement of elastic and nonlinear behavior with that obtained using conventional software. The dynamic simulation allows the analysis of progressive collapse sequence providing ease in the assessment of performance and identification of critical members. The ground acceleration data used is selected to be compatible with the project site's seismic design spectrum. Strengthening critical members is accomplished by recalculation of spring parameters based on the capacity increase and the material used. This paper analyzes a newly designed and an existing residential building using the proposed method and shows that it is capable of simulating the seismic performance and the potential collapse mechanism. The results show that increasing member dimension and applying CFRP are applicable to prevent collapse.