TY - JOUR
T1 - Experimental study on workability and permeability of sandy soils conditioned with thickened foam
AU - Feng, Zhiyao
AU - Wang, Shuying
AU - Qu, Tongming
AU - Zheng, Xiangcou
AU - Ling, Fanlin
PY - 2024
Y1 - 2024
N2 - Water spewing and muck plugging often occur during earth pressure balance (EPB) shield machines tunnelling in water-rich sandy strata, even though the conventional foam has been employed to condition sandy soils. In this study, a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed. In contrast to conventional foam-conditioned sands, the thickened foam-conditioned sand has a low permeability due to the consistent filling of soil pores with the thickened foam, and the initial permeability coefficient decreases by approximately two orders of magnitude. It also exhibits a suitable workability, which is attributed to the enhanced capability of the thickened foam to condition sandy soils. In addition, the effect of concentration on the stability of the foam is explained by the Gibbs-Marangoni effect, and conditioning mechanisms for the thickened foam on sands are discussed from the evolution of foam bubbles.
AB - Water spewing and muck plugging often occur during earth pressure balance (EPB) shield machines tunnelling in water-rich sandy strata, even though the conventional foam has been employed to condition sandy soils. In this study, a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed. In contrast to conventional foam-conditioned sands, the thickened foam-conditioned sand has a low permeability due to the consistent filling of soil pores with the thickened foam, and the initial permeability coefficient decreases by approximately two orders of magnitude. It also exhibits a suitable workability, which is attributed to the enhanced capability of the thickened foam to condition sandy soils. In addition, the effect of concentration on the stability of the foam is explained by the Gibbs-Marangoni effect, and conditioning mechanisms for the thickened foam on sands are discussed from the evolution of foam bubbles.
KW - Earth pressure balance (EPB) shield
KW - Foam-conditioned sand
KW - Permeability
KW - Thickened foam
KW - Workability
UR - http://www.scopus.com/inward/record.url?scp=85175426568&partnerID=8YFLogxK
U2 - 10.1016/j.jrmge.2023.05.015
DO - 10.1016/j.jrmge.2023.05.015
M3 - Article
AN - SCOPUS:85175426568
SN - 1674-7755
VL - 16
SP - 532
EP - 544
JO - Journal of Rock Mechanics and Geotechnical Engineering
JF - Journal of Rock Mechanics and Geotechnical Engineering
IS - 2
ER -