Simulating lifetime of embankments : from construction process to deformation and failure due to heavy rain / earthquake

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H06099
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Geotechnical engineering
• Research Institution: Yokohama National University
• Principal Investigator: KIKUMOTO MAMORU 横浜国立大学, 大学院都市イノベーション研究院, 准教授 (90508342)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 土構造物 / 締固め / 浸水崩壊 / 液状化 / 構成則 / 限界状態 / 状態境界面 / シミュレーション

Outline of Final Research Achievements

The conventional deformation and failure analysis of the embankment require the compacted soil's physical properties after the construction. However, the embankment parameters are set arbitrary, and the mechanical stability of the embankment could not be adequately evaluated. Thus, this research project aimed to develop a rational simulation method which incorporates the embankment's whole life from the construction (compaction) process to the deformation and failure due to rainfall or earthquake. The model is based on a critical state model and extended for unsaturated soils using Bishop's effective stress, rational soil-water characteristic curve, and extended state boundary surface. It is shown that the proposed model could reproduce the mechanism of the compaction, including upper-convex compaction curve and its transition due to the increase in the compaction energy. The model could also predict the behavior of compacted soils such as wetting-induced deformation.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

土構造物の力学的安定性は、含水比や締固めエネルギーといった締固め品質に大きく影響を受ける。しかし、従来は築造後の土構造物に対して恣意的にパラメータを設定して安定性評価が行われてきた。本研究では、土構造物の締固め築造過程から、降雨による浸水崩壊や地震時の液状化まで一貫してシミュレートできる手法が実現された。この手法を用いれば、築造過程から変形・破壊まで土構造物の一生をシミュレートする地盤解析技術が確立された。ここで開発された解析技術をさらに地盤材料の風化・侵食現象に拡張することで、長期供用期間を経た土構造物の安定性をより精緻に予測できるものと考えられる。