Enhanced analysis of elastic wave propagation and development of soil health monitoring system

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15084
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: The University of Tokyo
• Principal Investigator: OTSUBO MASAHIDE 東京大学, 生産技術研究所, 助教 (80804103)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 地盤工学 / 波動伝播 / 地盤剛性 / 室内試験 / 個別要素法 / 模型実験 / 地盤陥没 / 内部侵食

Outline of Final Research Achievements

This research aimed at proposing novel methods to utilize the result of wave velocity logging for the growing demand of performance-based design of geotechnical structure. A series of laboratory element tests, model tests, and numerical simulations were conducted. The outcome of the project suggests that the wave measurement data can provide not only soil stiffness, but also soil properties such as particle size distribution and the presence of underground cavities, without distracting the ground. Furthermore, by monitoring changes in wave signals periodically, the non-destructive measurement can be used to detect the soil softening due to the accumulation of shear strain and the loss/suffusion of fine particles from the ground due to seepage flow.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

近年、豪雨や地震によるダムや河川堤防の決壊、及び道路の陥没事故が頻発している。老朽化したインフラほど脆弱であるため、適切な維持管理手法の確立が急務である。地盤調査の一つである速度検層の新たな活用手法を検討した結果、弾性波シグナルの分析技術の高度化を図ることで、弾性波速度以外の地盤情報の取得、さらに、地盤の健全度をモニタリングできる新たな技術の創出に繋がる可能性を見出した。本研究では、このような非破壊検査技術を構築する際に必要となる基礎的な知見を示した。