Abstract
Japan is a land of earthquakes. The great east Japan earthquake occurred on March 11, 2011. This was immense damage. Particularly, many high rise structures in which were a long distance from the hypocenter of the earthquake resonated with the long period ground motion. Long period ground motion has a predominant period of from a few seconds to ten seconds and a duration time is more than a few minutes. Industrial plants, there are boiler plants as a long period structure, and they are in danger of resonating by long period ground motion. Recently many industrial plants require countermeasure for long period ground motion. Various viscous dampers have been proposed and applied to actual structures to suppress vibration response. However the vibration control performance decreases with the long duration time, because of a temperature rise of the viscous material. Therefore there is concern that these viscous dampers can not suppress vibration response in case of the long period ground motion. In order to solve this problem, the authors propose a viscous-friction damper in series. In this hybrid damper, the friction damper can absorb vibration energy as well in case of the long period ground motion. In this paper, we conducted seismic response analysis of the hybrid damper which was installed a boiler plant.
