As the result of vibration experiments, the normal ball-type continued to shake, and the problem not to come back to an original position occurred
even after the vibration stand stopped.
Because the ball-type device has low damping force, it may cause a resonant amplification and big shaking more than expected
when matching the direction of the earthquake wave with the direction where a isolation stand was restored.
→Movie of the Noto earthquake wave →Movie of the Kobe earthquake wave
Because the restoring force strongly acts with the ball-type device, it continues shaking after a earthquake stopped.
It continues working like a pendulum due to the lack of damping force.
However, the marble type bearing can stop shaking immediately after an earthquake stopped because it has a damping force.
When an earthquake is happened, the isolation device of marble type can be damping the vibration by a friction effect of the marble bearing.
Abserver® is able to gradually add to resistance without suddenly producing frictional resistance by means of the isolated plate of the polyhedron covering a marble bearing.
By this proof experiment, abserver® was able to reduce input wave of 1100gal (seismic intensity of 7 super class) to 140gal (seismic intensity 4 to 5).
It is confirmed that abserver® is high-performance isolation device which the collapse of base-isolation object and the malfunction of isolation device itself do not cause.