Laboratory Investigation on Excavation Performance of Foam-conditioned Weathered Granite Soil for EPB Shield Tunnelling

• Published in: KSCE journal of civil engineering Vol. 27; no. 12; pp. 5460 - 5469
• Main Authors: Lee, Hyobum, Oh, Jaehyun, Shin, Young Jin, Won, Jongmuk
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Civil Engineers 01.12.2023; Springer Nature B.V; 대한토목학회
• Subjects: Boring machines; Civil Engineering; Compressibility; Conditioning; Dredging; Drilling & boring machinery; Earth pressure; Engineering; Excavation; Foaming; Foaming agents; Geotechnical Engineering & Applied Earth Sciences; Granite; Industrial Pollution Prevention; Mechanical properties; Permeability; Rheological properties; Soil; Soil compressibility; Soil mechanics; Soil permeability; Soils; Torque; Tunnel construction; Tunnel Engineering; Tunneling shields; Workability; 토목공학; Weathered granite soil; Earth pressure balance; Tunnel boring machine; Soil conditioning; Foam
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-023-2163-9

As weathered granite soils are extensively distributed in the Korean Peninsula, determining the optimal foam conditioning parameters for weathered granite soils can provide a high workability, low permeability, and high compressibility of weathered granite soils for successful operation of an earth pressure balance (EPB) shield tunnel boring machine (TBM). In this study, a laboratory-scale excavation apparatus was developed to conduct various laboratory excavation simulations for measuring the excavation-induced torque and the abrasivity of cutter bits. In addition, slump values, compressibility, and permeability were measured to evaluate the workability of foam-conditioned weathered granite soils. From the experimental results, the optimal foaming conditions for the weathered granite soil was obtained at foam injection ratios ( F / R s) of 60–70%, foam expansion ratios ( FER s) of 15–18, and foaming agent concentrations ( C f ) of 3–4%. The experimental results presented in this study can provide the rheological, mechanical, and hydraulic behavior of foam-conditioned weathered granite soils for successful EPB TBM operation.