A Feasibility Study of Dewatering and Recovering as a Liquefaction Countermeasure for Existing Residential Areas

2015 Fiscal Year Final Research Report

• Project/Area Number: 26560182
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Chiba University
• Principal Investigator: Nakai Shoichi 千葉大学, 工学(系)研究科(研究院), 教授 (90292664)
• Co-Investigator(Kenkyū-buntansha): SEKIGUCHI TORU 千葉大学, 大学院工学研究科, 准教授 (50451753)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 液状化 / 不飽和化 / 既存宅地

Outline of Final Research Achievements

The 2011 Tohoku Earthquake caused extensive liquefaction damage over a wide area. A combined process of lowering and subsequent restoring the groundwater level can be used as a countermeasure against liquefaction, since this process is believed to create an unsaturated soil layer. The authors have conducted centrifuge shaking table tests in order to examine this idea by building a special test apparatus for this purpose. From the tests, it was found that the lowering and recovering process actually creates a layer of unsaturated soil and the thickness of liquefied soil is greatly decreased because of this process. In addition to the laboratory tests, the authors have also conducted various in-situ soil investigations including measurement of degree of saturation during a field demonstration experiment of dewatering. According to the results, it was confirmed that the lowering and recovering process of groundwater can create a layer of unsaturated soil also in an actual ground.

Free Research Field

地震工学・地盤工学