APPLICATION OF THE BASELINE STIFFNESS METHOD FOR DAMAGE DETECTION OF AN RC BUILDING WITHOUT BASELINE MODAL PARAMETERS UTILIZING THE INDEPENDENT COMPONENT ANALYSIS FOR MODAL EXTRACTION

In this paper, a damage detection study is presented for a seven-story concrete building. This structure was affected by the 1994 Northridge earthquake. Acceleration signals of the damaged system are processed utilizing both the Independent Component Analysis and the Frequency Domain Decomposition Method to extract modal parameters. Utilizing solely these parameters from the damaged structure and the approximate undamaged lateral stiffness of the first storey, a pre-damage state is determined. Damage assessment is achieved by the Baseline Stiffness Method and comparing the computed undamaged state of the building and the damaged one to detect loss of stiffness on each element of the structure. Advantages of the proposed methods are discussed to demonstrate the feasibility of the methodology to extract modal parameters and to identify structural damage in buildings without baseline modal information.