Understanding the diversity of liquefaction and fluid transport using dimensionless numbers

2015 Fiscal Year Final Research Report

• Project/Area Number: 24510246
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural disaster science
• Research Institution: Kanazawa University
• Principal Investigator: SUMITA IKURO 金沢大学, 自然システム学系, 准教授 (90334747)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 液状化 / 低浸透率層 / 地震 / 振動実験 / 噴砂 / 粉粒体 / 加速度 / 周波数

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.

Free Research Field

地球惑星ダイナミクス