Identification of Building Parameters Considering Soil-Structure Interaction Based on Observed Earthquake Records

A typical mid-to low-rise building is subject to strong dynamic interaction effects due to its relative degree of flexibility with the soil. Thus, it is necessary to take this effect into account when evaluating the seismic performance of such buildings. In this paper, we apply the modal iterative error correction method (MIEC method) to the foreshock records of the 2011 Tohoku earthquake to identify the coupled superstructure–foundation–soil system in a real building with few observation points. For this, observations made on the first, second, fifth, and eighth floors of an eight-story steel-reinforced concrete were used for identification of building parameters. In this earthquake, the response of each part of the building is within a linear range. First, the stiffness of the superstructure is identified as a parameter in the fixed-foundation model. Next, this stiffness value is used to create a Sway-Rocking model, and the identification was performed using soil spring as a parameter. The identification results for a real building with limited number of observation points, including soil springs in a linear range, showed good correspondence with the observed values.