Identification of flexible buildings with bending deformation and the unmeasured earthquake ground motion

Abstract

It is important to explore efficient algorithms for the identification of both structural parameters and unmeasured earthquake ground motion. Recently, the authors proposed an algorithm for the identification of shear-type buildings and unknown earthquake excitation. In this paper, it is extended to the investigation of the identification of flexible buildings with bending deformation and the unmeasured earthquake ground motion. In the absolute co-ordinate system, the unmeasured ground motion can be treated as an unknown translational force and a bending moment at the 1st floor level of a flexible building. Structural unknown parameters above the 1st story of the building can be identified by the extended Kalman estimator and the 1st story stiffness and the unmeasured ground motion are subsequently estimated based on the least-squares estimation. The proposed algorithm is further extended to the identification of tall bending-type buildings based on substructure approach. Inter-connection effect between sub-buildings is treated as ‘additional unknown inputs’ to sub-buildings, which are estimated by the extended Kalman estimator without the measurements of rotational responses. Numerical examples demonstrate the identification of a multi-story, tall bending-type building and its unmeasured earthquake ground motions using only partial measurements of structural absolute responses.