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Since earthquake motion has been amplified in the buildings structure when it affects the
equipment, the earthquake motion put in the equipment is estimated as the maximum
acceleration level; 4 m/s 2 (AT04), 6 m/s 2 (AT06), and 8 m/s 2 (AT08) horizontally and vertical
acceleration is half level of horizontal one. When the estimation is 8 m/s 2 horizontally and 4
m/s 2 vertically, seismic intensity scale is MM8. Using this artificial earthquake motion as the
one affecting the equipment, the authors made an investigation thorough testing in the
following chapters.
Shaking Table Test
A shaking table test has been conducted using a three-dimensional shaking table with an actual
equipment system set up on it together with the raised floor, in order to evaluate earthquake
response characteristics of the equipment and vibration control effect achieved by the
low-stiffness and high-damping rubber. Dummy weights were placed evenly on eight shelves of
the equipment. In case A and B, the rubber type A and B are used. In case N, no rubber is used.
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(1) Horizontal (2) Vertical
Fig. 3
ACCELERATION WAVE OF ARTIFICIAL EARTHQUAKE MOTION (10m/sec 2 )
S 15 Period (sec)
0.1 1
Period (sec)
Fig. 4
ACCELERATION RESPONSE SPECTRA OF ARTIFICIAL EARTHQUAKE MOTION
(6m/sec 2 : AT06)