Long-Term Monitoring of Dynamic Properties and Device Characteristics of a Base-Isolated Building by Vibration Experiments and Observations

Abstract

Properties of building response and base-isolation devices are evaluated by periodic vibration experiments and earthquake/microtremor observations over nine years from the completion of the building using permanent equipment for vibration experiments and response observations of a base-isolated building. The building is capable of free vibration experiments with an initial displacement of 140 mm using jacks installed in the seismic isolation layer, and forced vibration experiments using moving mass structure installed on the roof. Parameter estimation was conducted considering viscous and friction damping of devices. Direct observation of damping force of oil-dampers show complex characteristics and its variation and variability. Results will lead to evaluate the performance change of seismic isolated buildings after large earthquakes and long-term operation.