Influence of the construction process and nonstructural components on the modal properties of a five-story building

Summary: A full-scale five-story reinforced concrete building was built and tested on the NEES-UCSD shake table during the period from May 2011 to May 2012. The purpose of this test program was to study the response of the structure and nonstructural components and systems (NCSs) and their dynamic interaction during seismic base excitation of different intensities. The building specimen was tested first under a base-isolated condition and then under a fixed-based condition. As the building was being erected, an accelerometer array was deployed on the specimen to study the evolution of its modal parameters during the construction process and placement of major NCSs. A sequence of dynamic tests, including daily ambient vibration, shock (free vibration) and forced vibration tests (low-amplitude white noise and seismic base excitations), were performed on the building at different stages of construction. Different state-of-the-art system identification methods, including three output-only and two input-output methods, were used to estimate the modal properties of the building. The obtained results allow to investigate in detail the effects of the construction process and NCSs on the dynamic parameters of this building system and to compare the modal properties obtained from different methods, as well as the performance of these methods.