A giant earthquake of magnitude 9.0 occurred in Pacific Ocean off of Tohoku District Japan on March 11,2011. The highest seismic intensity of 7 in JMA scale was recorded in Miyagi. In the Tohoku district, around 230 b...A giant earthquake of magnitude 9.0 occurred in Pacific Ocean off of Tohoku District Japan on March 11,2011. The highest seismic intensity of 7 in JMA scale was recorded in Miyagi. In the Tohoku district, around 230 buildings are seismically isolated （hereafter, SI） mainly by elastomeric isolators （seismic rubber bearings）. According to the official survey reports by several organizations （for example）, the records of those buildings have verified the effectiveness of the seismic isolation. The response acceleration of the SI buildings was reduced by 30% to 50% of the input ground acceleration. Additionally, the difference of the conditions inside the room between SI and the fixed-base buildings was obvious as well as the damage in main structures of the buildings. The displacements of the isolators by the earthquake were around 200 mm according to the records of the instruments. As a result, the performance of SI buildings and the elastomeric isolators in the Tohoku District -- Off the Pacific Ocean Earthquake 2011 were excellent, and the efficiency of the seismic isolation was verified by the records of many buildings in wide area.展开更多
The three dimensional lead rubber dish spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish spring bearing (DSB) with damper in series. The 3DB put forward in t...The three dimensional lead rubber dish spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi dimensional seismic responses of 3D base isolated frame structures are established. Taking a five storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.展开更多
文摘A giant earthquake of magnitude 9.0 occurred in Pacific Ocean off of Tohoku District Japan on March 11,2011. The highest seismic intensity of 7 in JMA scale was recorded in Miyagi. In the Tohoku district, around 230 buildings are seismically isolated （hereafter, SI） mainly by elastomeric isolators （seismic rubber bearings）. According to the official survey reports by several organizations （for example）, the records of those buildings have verified the effectiveness of the seismic isolation. The response acceleration of the SI buildings was reduced by 30% to 50% of the input ground acceleration. Additionally, the difference of the conditions inside the room between SI and the fixed-base buildings was obvious as well as the damage in main structures of the buildings. The displacements of the isolators by the earthquake were around 200 mm according to the records of the instruments. As a result, the performance of SI buildings and the elastomeric isolators in the Tohoku District -- Off the Pacific Ocean Earthquake 2011 were excellent, and the efficiency of the seismic isolation was verified by the records of many buildings in wide area.
文摘The three dimensional lead rubber dish spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi dimensional seismic responses of 3D base isolated frame structures are established. Taking a five storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.
