Effect of adsorbed water on compression behavior of high liquid limit soils

Abstract

The aim of this study is to reveal the mechanism underlying the influence of adsorbed water on the deformation of high liquid limit soils, and establish the prediction equation of compressibility coefficient, which is helpful for engineering application. high liquid limit clay, high liquid limit silt and clayey sand were selected for laboratory tests. The initial adsorbed water of the soil samples was controlled by different concentrations of NaCl solution, and the adsorbed water contents of three soil samples in different concentrations of salt solution were determined by thermogravimetric analysis. Meanwhile, the variations of liquid limit (LL) and plastic limit (PL) at different concentrations were also determined by the liquid-plastic limit combine tester. In order to study the effect of adsorbed water on the consolidation characteristics, saturated consolidation tests were carried out on three soil samples under different concentrations of salt solutions. The results show that as the concentration of salt solution increases, the adsorbed water content, LL and PL decrease accordingly. For saturated soil samples with the same initial void ratio, the compression index decreases with an increase in adsorbed water content. At the same modified void ratio, the compression curves of different soils tend to be consistent. Based on the results of this study and those available in the literature, the prediction equations of initial void ratio and compression index were established. Compared with the unmodified void ratio, the modified void ratio can normalize the compression behavior of different soil samples since the adsorbed water plays a skeletal role in the soil. Thus, the precision of the prediction equation of compression index can be improved using the modified void ratio.

Keywords

high liquid limit soil / adsorbed water / consolidation / void ratio / compressibility

References

[1] ZhangR, XiaoY-P, WuM, et al. . Measurement and engineering application of adsorbed water content in fine-grained soils [J]. Journal of Central South University, 2021, 28(5): 1555-1569

[2] ZhangJ H, LiF, ZengL, et al. . Effect of cushion and cover on moisture distribution in clay embankments in Southern China [J]. Journal of Central South University, 2020, 27(7): 1893-1906

[3] ZhangJ, LiF, ZengL, et al. . Numerical simulation of the moisture migration of unsaturated clay embankments in Southern China considering stress state [J]. Bulletin of Engineering Geology and the Environment, 2021, 80(1): 11-24

[4] ZHANG Rui, WU Meng-li, KUMAR P, et al. Influence of loosely bound water on compressibility of compacted finegrained soils [J]. Advances in Civil Engineering, 2020: 1–14. DOI: https://doi.org/10.1155/2020/1496241.

[5] DengY F, YueX B, CuiY J, et al. . Effect of pore water chemistry on the hydro-mechanical behaviour of Lianyungang soft marine clay [J]. Applied Clay Science, 2014, 95: 167-175

[6] BoltG H. Physico-chemical analysis of the compressibility of pure clays [J]. Géotechnique, 1956, 6(2): 86-93

[7] SongM, ZengL, HongZ. Pore fluid salinity effects on physicochemical-compressive behaviour of reconstituted marine clays [J]. Applied Clay Science, 2017, 146: 270-277

[8] WenM, TianY, WuW, et al. . Influence of thermal contact resistance on dynamic response of bilayered saturated porous strata [J]. Journal of Central South University, 2022, 29(6): 1823-1839

[9] WuQ, MaoX, WangC. Mechanism of bound water effects on the secondary consolidation property of soft soil [J]. China Journal of Highway and Transport, 2021, 34(7): 215-225(in Chinese)

[10] LiS, WangC, WuQ, et al. . Variations of bound water and microstructure in consolidation-creep process of Shanghai mucky clay [J]. Rock and Soil Mechanics, 2017, 38(10): 2809-2816(in Chinese)

[11] ZongM, TiangY, LiangR, et al. . One-dimensional nonlinear consolidation analysis of soil with continuous drainage boundary [J]. Journal of Central South University, 2022, 29(1): 270-281

[12] SkemptonA W, JonesO T. Notes on the compressibility of clays [J]. Quarterly Journal of the Geological Society, 1944, 100(1–4): 119-135

[13] NagarajT S, SrinivasaM B R. A critical reappraisal of compression index equations [J]. Géotechnique, 1986, 36(1): 27-32

[14] HabibbeygiF. Determination of the compression index of reconstituted clays using intrinsic concept and normalized void ratio [J]. International Journal of GEOMATE, 2017, 13(39): 54-60

[15] ChowdhuryB, HaqueA, MuhunthanB. New pressure-void ratio relationship for structured soils in the virgin compression range [J]. Journal of Geotechnical and Geoenvironmental Engineering, 2014, 140(8): 06014009

[16] AkbarimehrD, EslamiA, ImamR. Correlations between compression index and index properties of undisturbed and disturbed Tehran clay [J]. Geotechnical and Geological Engineering, 2021, 3975387-5393

[17] ShangX Y, ZhouG Q, KuangL F, et al. . Compressibility of deep clay in East China subjected to a wide range of consolidation stresses [J]. Canadian Geotechnical Journal, 2015, 52(2): 244-250

[18] ChaneyR C, DemarsK R, SridharanA, et al. . Percussion and cone methods of determining the liquid limit of soils: Controlling mechanisms [J]. Geotechnical Testing Journal, 2000, 23(2): 236

[19] YoonG L, KimB T, JeonS S. Empirical correlations of compression index for marine clay from regression analysis [J]. Canadian Geotechnical Journal, 2004, 4161213-1221

[20] NishidaY. A brief note on compression index of soil [J]. Journal of the Soil Mechanics and Foundations Division, 1956, 82(3): 1-14

[21] AzzouzA S, KrizekR J, CorotisR B. Regression analysis of soil compressibility [J]. Soils and Foundations, 1976, 16(2): 19-29

[22] ZHAO You-ming. Deformation parameters of Shenzhen soft clay [J]. China Railway Science, 2004(3): 41–44. DOI: https://doi.org/10.3321/j.issn:1001-4632.2004.03.009. (in Chinese)

[23] GaoY, ZhangS, GeX. Comparisons of compression index of Chinese coastal soft clay and soils from foreign regions [J]. Rock Soil Mech, 2017, 38(9): 2713-2720(in Chinese)

[24] Al-KhafajiA W N, AnderslandO B. Equations for compression index approximation [J]. Journal of Geotechnical Engineering, 1992, 118(1): 148-153

[25] RayS, MishraA K, KalamdhadA S. Influence of real and synthetic municipal solid waste leachates on consolidation and shear strength behaviour of bentonites [J]. Environmental Science and Pollution Research, 2021, 28(24): 30975-30985

[26] ChengG, ZhuH, WenY, et al. . Experimental investigation of consolidation properties of nano-bentonite mixed clayey soil [J]. Sustainability, 2020, 12(2): 459

[27] WidodoS, IbrahimA. Estimation of primary compression index (C_c) using physical properties of Pontianak soft clay [J]. International Journal of Engineering Research and Applications, 2012, 252231-2235

[28] ChaiJ C, AgungP M A, HinoT, et al. . Estimating hydraulic conductivity from piezocone soundings [J]. Géotechnique, 2011, 61(8): 699-708

[29] HongS J, KimD H, ChoiY M, et al. . Prediction of compression index of Busan and Inchon clays considering sedimentation state [J]. Journal of the Korean Geotechnical Society, 2011, 27(9): 37-46

[30] MohdA J, TahaM R, AhmedJ, et al. . Prediction and determination of undrained shear strength of soft clay at Bukit Raja [J]. Pertanika Journal of Science & Technology, 1997, 5(1): 111-126

[31] BergadoD T, LongP V, BaalasubramaniamA S. Compressibility and flow parameters from PVD improved soft Bangkok clay [J]. Geotechnical Engineering, 1996, 27: 1-20

[32] YuS J, ChaeY S, KimJ K, et al. . Effect of disturbance on the compressibility characteristics of marine clay [J]. Journal of the Korean Geotechnical Society, 2007, 23(12): 95-107