ロッキング振動抑制装置のいらない3 次元免震装置の基礎的研究

抄録

Japan is one of the most earthquake-prone countries in the world. Accordingly, the earthquake resistance of structures is required. To secure the earthquake resistance of the structure, the application of the 3-dimensional isolation system which reduces the horizontal and vertical seismic forces is effective. However, when the vertical frequency of the 3- dimensional isolation system is low, the rocking vibration occurs. In this case, the additional devices are necessary for suppression of rocking vibration. Consequently, the 3-dimensional isolation system becomes complicated. The response in the vertical direction is reduced at the appropriate vertical stiffness of the device, furthermore the rocking vibration is negligible. The development of the 3-dimensional isolation system that would not require the devices for suppression of rocking vibration is effective for improving the earthquake resistance of general industrial equipment. Furthermore, that is effective for the spread of device. In this paper, we will investigate the applicability of a 3-dimensional isolation system that would not require the devices for suppression of rocking vibration to general industrial facility. The seismic response analysis was carried out with simultaneous horizontal and vertical input. As a result, the response of the equipment near the natural frequency of 10 Hz in the vertical direction decreases. In addition, the response of the equipment in the horizontal direction is much smaller than the input ground motion. Accordingly, 3-dimensional isolation system has high seismic isolation effect. Furthermore, the rotation angle of the equipment is about 10^-4 rad. In addition, it does not adversely affect the seismic isolation performance. Therefore, no locking suppression device is required.