Seismic analyses of a five-story residential building supported by T-BAGS base isolation and vibration control system

Abstract

T-BAGS system developed by Takeuchi Construction Inc. is a seismic base isolation and vibration control system that uses two stacked layers of sandbags which slide between them. Numerical dynamic analyses of a typical residential five-story building with and without the T-BAGS system are conducted. The building and the T-BAGS system are integrated and modeled as a three-dimensional series of masses and nonlinear springs. The shear force vs. shear deformation behavior of the sandbags is modeled using the Ramberg-Osgood model based on experimental results. The slippage at the interface between the upper and lower sandbags is assumed to follow the Mohr-Coulomb friction law. It is shown from the analytical results that the response acceleration of the building induced by severe earthquakes can be considerably attenuated using the T-BAGS base isolation and vibration control system. It is emphasized that the hysteretic shear behavior of the sandbags contributes to the vibration control efficiently