Development of safety evaluation technique of earth dam against combined effects by earthquake and rainfall

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06293
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41030:Rural environmental engineering and planning-related
• Research Institution: Shimane University
• Principal Investigator: UENO Kazuhiro 島根大学, 学術研究院環境システム科学系, 助教 (60560167)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 地震 / 降雨 / ため池 / 弾性波速度 / ベンダーエレメント

Outline of Final Research Achievements

Combined effects by earthquake and rainfall are not considered in the current safety evaluation of earth dam. In this study, laboratory investigations were conducted to assess the combined effects by earthquake and rainfall on mechanical properties of soil. As a result, it was suggested that, when earthquake and rainfall act in combination, the influence of each action on the strength and deformation characteristics is independent, and the influence of the order of occurrence is small. Moreover, the influence of the initial shear stress on the relationship between shear wave velocity, which can be measured on site, and liquefaction strength was evaluated.

Free Research Field

施設機能工学

Academic Significance and Societal Importance of the Research Achievements

地震と豪雨の複合的な作用がため池堤体を構成する土質材料の強度・変形特性へ及ぼす影響を明確にしたことで，災害外力の複合作用に対する安全性評価へ資する知見を得たことである．また，ため池現地で観測可能なせん断波速度と液状化強度の相関関係を示したことにより，せん断波速度を指標としたため池堤体の安全性評価の高度化が期待でき，安全な農村環境の構築へ貢献できると考えられる．