| Budget Amount *help |
¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2012: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Outline of Final Research Achievements |
We conducted a series of laboratory experiments in which a liquid-immersed granular medium with a less permeable upper layer is shaken vertically. We varied (a) the acceleration and frequency of shaking, and (b) the liquid viscosity. The experiments were conducted to understand the diversity and scaling relation of the phenomena associated with liquefaction. From the experiments we found that (i) a gravitational instability occurs as a consequence of accumulation of the liquid beneath the less permeable upper layer, (ii) there is a critical acceleration for the instability to occur, (iii) the critical acceleration decreases when the liquid has a higher viscosity. We formulated scaling laws to explain these results. Our results indicate that both shaking acceleration and velocity are important for liquefaction. Furthermore they show that when the liquid is more viscous, a granular medium can become more susceptible to liquefaction due to the enhanced interparticle lubrication.
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