Durability of the cement-treated clay ground constructed in coastal area

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K04348
• 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: University of Miyazaki
• Principal Investigator: Suetsugu Daisuke 宮崎大学, 工学部, 教授 (30423619)
• Co-Investigator(Kenkyū-buntansha): 日野 剛徳 佐賀大学, 理工学部, 教授 (20295033)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: セメント処理土 / 透水性 / 強度 / 劣化 / 海水

Outline of Final Research Achievements

When saline groundwater begins to flow into cement-treated soil, its permeability decreases. As salt continues to flow into the treated soil, the permeability increases. This phenomenon is caused by the improved pore size of the treated soil as calcium leaches out.
As calcium is leached from the treated soil, the soil gradually changes from expansive to compressible, and the shear strength of the treated soil decreases. A residual amount of calcium that causes a rapid decrease in shear strength exists, which depends on the amount of cement added when mixing the soil.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

海水と接触するセメントや石灰で混合処理された土は固化成分のカルシウムの溶脱が促進され劣化が進行する。そのメカニズムはほぼ明らかにされてきたが、劣化の進行に伴う力学的特性の変化はほとんど明らかにされていなかった。本研究では劣化の進行に伴う処理土の透水性と強度変形特性の変化を明らかにした。これらの成果は固化処理工法で安定化された地盤の長期的な安定性の理解ならびに評価手法の開発に資する知見である。