Dynamic behaviour of an asymmetric building: Experimental and numerical studies

The paper presents a study on the seismic assessment of a 21-story building having an asymmetrical plan. The study applies the approach using in-situ measurements to assess the building's seismic performance. According to preliminary observations on site, the soil may have a significant influence on the building's behaviour. That is why it is important to isolate the behaviour of the building from the soil effect (fixed-base structure). First, in-situ dynamic measurements are conducted to identify dynamic characteristics of the building. The Frequency Domain Decomposition (FDD) method is used to determine the vibration modes of the building in three dimensions (3D). First three vibration modes with close frequencies and unusual mode shapes were identified, which shows the relevance of the used method in the case of buildings having complex behaviour. Second, the relevance of the applied approach was checked by using 3D Finite Element (FE) modelling, in both cases: fixed-base structure and soil + structure system.