起震車を使用した人工地震後の動揺感についての検討

抄録

Purpose
This study was performed to examine what duration the feeling of being shaken can persist after the end of an earthquake by subjecting 12 volunteers to an artificial earthquake using an earthquake simulator vehicle.
Methods
The time from cessation of shaking in the earthquake simulator vehicle to the point at which the subject felt that the shake had ceased was measured.
Experiment 1: The seismic intensity was set at lower 6 to 2 on the Japanese seismic scale.
Experiment 2: The seismic stimulation time of 1 minute and 3 minutes were compared.
Experiment 3: Seismic stimulation was compared between rolling and pitching.
Experiment 4: The experiment was carried out with the subject's body position changed.
Experiment 5: Seismic stimulation was delivered intermittently rather than continuously.
Experiment 6: Seismic stimulation was delivered upon each of the following two different explanations:
“The earthquake will cease in 1or 3 minutes”.
“We don't know how long the earthquake will last. The seismic intensity may also change”.
However, the actual stimulation delivered was at seismic intensities of upper 5 for 1 minute and 2 for 1 minute.
Results
Experiment 1 to 5: The duration from the end of the evoked quake until cessation of the post-quake feeling of ground shaking was within 3 seconds on average in all instances.
Experiment 6: There was a significant prolongation of the mean time after an intensity 2 shake as well as that after an intensity of upper 5 when the test was conducted with the prior explanation:“We don't know how long the earthquake will last. The seismic intensity may also change” (P<0.05).
Discussion
This finding indicated that the feeling of the ground shaking after an earthquake is likely to be affected by psychosomatic or psychological factors.