Development and verification of groundwater cut-off technology using field-generated soil directly to enable zero emissions

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04254
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Okayama University
• Principal Investigator: Komatsu Mitsuru 岡山大学, 環境生命自然科学学域, 教授 (50325081)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 注入 / 懸濁液 / 透水係数 / 粘度 / 通水実験

Outline of Final Research Achievements

In this study, we focused on in-situ samples to develop a new clay-based injection method. First, a method for extracting fine grains from the field samples was studied, and then the characteristics of the suspension with the extracted fine grains were investigated. The effect of the method was verified by examining the behavior of the suspension when it was pressure-injected into the specimen in a horizontal one-dimensional column and the change in hydraulic conductivity in a hydraulic experiment in which the hydraulic gradient was increased in steps. The results showed that the suspension mixed with bentonite to increase viscosity was highly effective in reducing hydraulic conductivity. The results of the injection range study using a rotating sectional 2D soil tank suggested that the permeability of the kaolin clay suspension with smaller particle size was higher than that of the suspension with larger particle size.

Free Research Field

地下水

Academic Significance and Societal Importance of the Research Achievements

地盤の止水を目的とした注入材の特性を明らかにする研究はこれまでにも数多く実施されているが，産業副産物を注入材として用いる点に着目した研究事例はみられない．本研究では，セメントや薬液を用いたものに代わる環境への負荷が少ない材料を用いた新たな注入工法を創造することにより，河川堤防における高透水性地盤やトンネル掘削時の湧水に対する注入以外にも汚染地下水の拡散制御壁への利用，地盤沈下の原因となる粘土層の圧密沈下防止対策としての利用等への応用，砂質地盤を注入により粘性地盤に改良することで液状化を防止する技術への応用等への波及効果が期待できる．