Elucidation of the long-term consolidation settlement behavior of soft clay after the earthquake and impact assessment on the structure foundation

2015 Fiscal Year Final Research Report

• Project/Area Number: 26820190
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Geotechnical engineering
• Research Institution: Hokkaido University
• Principal Investigator: Isobe Koichi 北海道大学, 工学(系)研究科(研究院), 准教授 (70452084)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 粘土の構造 / 不かく乱試料 / 残留間隙水圧 / 地震後圧密 / 繰返し三軸試験 / 遠心模型実験 / 土水連成FE解析

Outline of Final Research Achievements

Subsidence in Kashiwazaki has been observed after the earthquake of 2007. Unlike subsidence due to drawdown of groundwater level, it has become clear that there is no correlation between the subsidence and the groundwater level. The previous research has been concluded that long-term dissipation behavior of excess pore water pressure (EPWP) occurred during the earthquake is the main factor. However, because it does not match with the observations, the addition field survey was conducted to explain the remaining conditions of EPWP and understand the continuous clay soil constants. It were used to improve the accuracy of the simulation and investigate the effect on settlement behavior under various conditions. As the mechanism, focusing on the compression softening phenomenon caused by loss of the structure, through the results of the cyclic triaxial test and centrifugal model tests, it was reviewing the possibility that compression softening phenomenon occurs.

Free Research Field

地盤工学