不同應力狀態下孔隙結構特征對土-水特征曲線的影響

陳宇龍; 黃棟

doi:10.13374/j.issn2095-9389.2017.01.019

不同應力狀態下孔隙結構特征對土-水特征曲線的影響

doi: 10.13374/j.issn2095-9389.2017.01.019

陳宇龍¹,
黃棟^2, ,

1) 東京大學土木工程系, 東京 113-8656, 日本
2) 中國科學院山地災害與地表過程重點實驗室, 成都 610041

基金項目:

國家自然科學基金資助項目（41301009）

詳細信息

中圖分類號: TU411
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出版歷程
- 收稿日期: 2016-02-17

Influence of pore structure characteristics on soil-water characteristic curves under different stress states

CHEN Yu-long¹,
HUANG Dong^{2
, ,}

1) Department of Civil Engineering, University of Tokyo, Tokyo 113-8656, Japan
2) Key Laboratory of Mountain Hazards and Surface Process, Chengdu 610041, China

摘要

摘要: 針對傳統土-水特征曲線測試儀無法實現荷載作用的不足，研制吸力控制式三軸試驗裝置，開展不同應力狀態作用下土-水特征曲線試驗，討論應力狀態對孔隙特征的作用.結果表明，固結壓力和基質吸力均能使土體產生不可逆的收縮變形.固結壓力越大，土顆粒就越緊密，孔隙比越小，孔隙尺寸和數量越小，滲透性越差，表現出較好的持水能力，空氣難以進入土體，土體排水困難，導致進氣值增大和減濕率減小.土-水特征曲線與孔隙結構特征的關系緊密，與應力狀態無直接關系.固結壓力對土-水特征曲線的影響是通過改變孔隙結構特征來體現的.孔隙結構特征相近時，應力狀態對其土-水特征曲線不會產生影響.
- 土-水特征曲線 /
- 應力狀態 /
- 孔隙結構 /
- 孔隙比 /
- 滯后
Abstract: Since traditional instruments cannot apply stress in soil-water characteristic curve tests, we develop a suction controlled triaxial apparatus, by which soil-water characteristic curve tests are performed under different stress states. Further, the influence of stress state on the pore characteristics is discussed. The results show that both consolidation pressure and matrix suction can lead to the irreversible contraction deformation of soil. The soil under a larger consolidation pressure has a denser structure and a less void, leading to a smaller pore size and quantity. So it results in a worse permeability. Accordingly, it shows a better water retentivity. Air can hardly enter and water can hardly drain out, which give rise to a larger air entry value and a smaller slope of the soil-water characteristic curve. The soil-water characteristic curve of a compacted soil mainly depends upon current void ratio, not directly upon stress state. The influence of consolidation pressure on the soil-water characteristic curve is embodied in pore distribution properties. For similar pore distribution properties, the soil-water characteristic curve should be similar regardless of stress state. A larger consolidation pressure causes a less hysteresis.
- soil-water characteristic curve /
- stress state /
- pore structure /
- void ratio /
- hysteresis

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參考文獻(18)

[1]	Fredlund D G, Xing A Q, Fredlund M D, et al. The relationship of the unsaturated soil shear to the soil-water characteristic curve. Can Geotech J, 1996, 33(3):440
[2]	Öberg A L, Sällfors G. Determination of shear strength parameters of unsaturated silts and sands based on the water retention curve. Geotech Test J, 1997, 20(1):40
[3]	Huang S Y, Barbour S L, Fredlund D G. Development and verification of a coefficient of permeability function for a deformable unsaturated soil. Can Geotech J, 1998, 35(3):411
[4]	Lim P C, Barbour S L, Fredlund D G. The influence of degree of saturation on the coefficient of aqueous diffusion. Can Geotech J, 1998, 35(5):811
[5]	Gallage C, Kodikara J, Uchimura T. Laboratory measurement of hydraulic conductivity functions of two unsaturated sandy soils during drying and wetting processes. Soils Found, 2013, 53(3):417
[6]	Ng C W W, Pang Y W. Influence of stress state on soil-water characteristics and slope stability. J Geotech Geoenviron Eng, 2000, 126(2):157
[8]	Tavakoli Dastjerdi M H, Habibagahi G, Nikooee E. Effect of confining stress on soil water retention curve and its impact on the shear strength of unsaturated soils. Vadose Zone J, 2014, 13(5):1
[9]	Irfan M, Uchimura T. Modified triaxial apparatus for determination of elastic wave velocities during infiltration tests on unsaturated soils. KSCE J Civ Eng, 2016, 20(1):197
[10]	Pham H Q. A Volume-Mass Constitutive Model for Unsaturated Soils[Dissertation]. Saskatchewan:University of Saskatchewan, 2005
[13]	Miller C J, Yesiller N, Yaldo K, et al. Impact of soil type and compaction conditions on soil water characteristic. J Geotech Geoenviron Eng, 2002, 128(9):733
[14]	Hu R, Chen Y F, Liu H H, et al. A water retention curve and unsaturated hydraulic conductivity model for deformable soils:consideration of the change in pore-size distribution. Géotechnique, 2013, 63(16):1389
[15]	Zhou A N, Sheng D C, Carter J P. Modelling the effect of initial density on soil-water characteristic curves. Géotechnique, 2012, 62(8):669
[16]	Fleureau J M, Verbrugge J C, Huergo P J, et al. Aspects of the behaviour of compacted clayey soils on drying and wetting paths. Can Geotech J, 2002, 39(6):1341
[18]	Bolt G E. Physico-chemical analysis of the compressibility of pure clays. Géotechnique, 1956, 6(2):86
[24]	Sillers W S, Fredlund D G, Zakerzadeh N. Mathematical attributes of some soil-water characteristic curve models. Geotech Geol Eng, 2001, 19(3):243
[25]	Sun D A, Sheng D C, Xu Y F. Collapse behaviour of unsaturated compacted soils with different initial densities. Can Geotech J, 2007, 44(6):673
[26]	Lee I M, Sung S G, Cho G C. Effect of stress state on the unsaturated shear strength of a weathered granite. Can Geotech J, 2005, 42(2):624
[27]	Rostami A, Habibagahi G, Ajdari M, et al. Pore network investigation on hysteresis phenomena and influence of stress state on the SWRC. Int J Geomech, 2013, 15(5):04014072