Geomechanics and Engineering

  • 제26권3호
  • /
  • Pages.275-288
  • /
  • 2021
  • /
  • 2005-307X(pISSN)
  • /
  • 2092-6219(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Hydromechanical behavior and prediction of unsaturated loess over a wide suction range

  • Jiang, Tong (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power) ;
  • Zhao, Jindi (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power) ;
  • Zhang, Junran (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power) ;
  • Wang, Lijin (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power) ;
  • Song, Chenyu (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power) ;
  • Zhai, Tianya (Henan Province Key Laboratory of Geomechanics and Structural Engineering, North China University of Water Resources and Electric Power)
  • 투고 : 2021.03.29
  • 심사 : 2021.08.03
  • 발행 : 2021.08.10
⟨ 이전 논문 다음 논문 ⟩

초록

Subgrade loess in arid and semi-arid regions subjected to high-suction conditions owing to low relative humidity and deep groundwater levels. Understanding the hydromechanical behavior of unsaturated compacted loess over a wide suction range is critical for resolving infrastructure problems in such areas. In this study, the water retention behavior of loess was investigated by imposing or measuring suction (s) using the axis translation technique, vapor equilibrium technique, and chilled mirror dew point technique. Triaxial tests were also performed to study the mechanical behavior of compacted loess under different net cell pressures (σ3n). The soil-water retention curves obtained using the different techniques are consistent. The degree of saturation and water content decreases significantly when s < 240 kPa, whereas the change of void ratio is relatively small. The water content versus s curves with different initial dry densities is coincident when s > 0.5 MPa, indicating that undrained triaxial tests can be considered as those under constant suction. For the same σ3n, specimens show strain-hardening, shrinkage, and drum-shaped shear failure under low-s conditions and strain-softening, dilatancy, and oblique section splitting under high-s conditions. The failure deviator stress and cohesion of the compacted loess specimens increase with increasing s over the full s range (0-299.37 MPa). An equation to predict the shear strength of unsaturated loess over a wide s range is proposed. The intersection of the capillary water retention curve and adsorption water retention curve is set as a reference point (sR), where capillary degree of saturation is applicable for s ≤ sR and adsorption degree of saturation is added for s > sR. The predicted and measured shear strengths of the compacted loess specimens are in good agreement.

키워드

과제정보

This study is financially supported by the National Natural Science Foundation of China (Grant No. 41602295), the Foundation for University Key Teacher by the Ministry of Education of Henan Province (Grant No. 2020GGJS-094), the Key Scientific Research Projects of Colleges and Universities in Henan Province (Grant No. 21A410002), the Natural Science Foundation of Guangxi (Grant No. 2019GXNSFAA245025), and the Doctoral Student Innovation Foundation of NCWU.

참고문헌

  1. Abd, I.A., Fattah, M.Y. and Mekkiyah, H. (2020), "Relationship between the Matric Suction and the Shear Strength in Unsaturated Soil", Case Stud. Construct. Mater., 13, e00441. https://doi.org/10.1016/j.cscm.2020.e00441.
  2. Alonso, E.E., Pereira, J.M., Vaunat, J. and Olivella, S. (2010), "A microstructurally based effective stress for unsaturated soils", Geotechnique, 60(12), 913-925. https://doi.org/10.1680/geot.8.P.002.
  3. Bishop, A.W. (1959), "The principle of effective stress", Teknisk Ukeblad, 106(39), 859-863.
  4. Bulut, R. and Leong, E.C. (2008), "Indirect measurement of suction", Geotech. Geol. Eng., 26(6), 633-644. https://doi.org/10.1007/s10706-008-9197-0.
  5. Cai, G., Zhou, A.N., Liu, Y., Xu, R.Z. and Zhao, C.G. (2020), "Soil water retention behavior and microstructure evolution of lateritic soil in the suction range of 0-286.7 MPa", Acta Geotechnica, 15, 3327-3341. https://doi.org/10.1007/s11440-020-01011-w.
  6. Chen, B., Ding, X.H., Gao, Y., Sun, D.A. and Yu, H.H. (2020), "Hydro-mechanical behavior of compacted silt over a wide suction range", Geomech. Eng., 22(3), 237-244. https://doi.org/10.12989/gae.2020.22.3.237.
  7. Chen, S., Ma, W. and Li, G. (2019), "Study on the mesostructural evolution mechanism of compacted loess subjected to various weathering actions", Cold Reg. Sci. Technol., 167, 102846. https://doi.org/10.1016/j.coldregions.2019.102846.
  8. Fredlund, D.G. and Xing A.Q. (1994), "Equations for soil-water characteristic curve", Can. Geotech. J., 31(4), 521-532. https://doi.org/10.1139/t94-061.
  9. Gao, Y., Sun, D.A., Zhou, A.N. and Li, J. (2020), "Predicting shear strength of unsaturated soils over wide suction range", Int. J. Geomech., 20(2), 04019175. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001555.
  10. Gao, Y., Sun, D.A., Zhu, Z.C. and Xu, Y.F. (2018), "Hydromechanical behavior of unsaturated soil with different initial densities over a wide suction range", Acta Geotechnica, 14(2), 417-428. https://doi.org/10.1007/s11440-018-0662-5.
  11. Gao, Y., Li, Z., Sun, D. A. and Yu, H.H. (2021), "A simple method for predicting the hydraulic properties of unsaturated soils with different void ratios", Soil Till. Res., 209(3), 104913. https://doi.org/10.1016/j.still.2020.104913.
  12. Greco, R. and Gargano, R. (2015), "A novel equation for determining the suction stress of unsaturated soils from the water retention curvebased on wetted surface area in pores", Water Resour. Res., 51(8), 6143-6155. https://doi.org/10.1002/2014WR016541.
  13. Greenspan, L. (1977), "Humidity fixed points of binary saturated aqueous solutions", J. Res. Nat. Bureau Standards A Phys. Chem., 81(1), 89-96. https://doi.org/10.6028/jres.081A.011.
  14. Guan, G.S., Rahardjo, H. and Choon, L.E. (2010), "Shear strength equations for unsaturated soil under drying and wetting", J. Geotech. Geoenviron. Eng., 136(4), 594-606. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000261.
  15. Hu, C.M., Wang, X.Y., Mei, Y., Yuan, Y.L. and Zhang, S.S. (2018), "Compaction techniques and construction parameters of loess as filling material", Geomech. Eng., 15(6),1143-1151. https://doi.org/10.12989/gae.2018.15.6.1143.
  16. Jiang, M.J., Zhang, F.G., Hu, H.J., Cui, Y.J. and Peng, J.B. (2014), "Structural characterization of natural loess and compacted loess under triaxial tests", Eng. Geol., 181, 249-260. https://doi.org/10.1016/j.enggeo.2014.07.021.
  17. Jiang, T., Wang, L.J., Zhang, J.R., Jia, H. and Pan, J.S. (2020), "Effect of water content on near-pile silt deformation during pile driving using PIV technology", Geomech. Eng., 23(2), 139-149. https://doi.org/10.12989/gae.2020.23.2.139.
  18. Jiang, Y., Chen, W.W., Wang, G.H., Sun, G.P. and Zhang, F.Y. (2016), "Influence of initial dry density and water content on the soil-water characteristic curve and suction stress of a reconstituted loess soil", B. Eng. Geol. Environ., 76(3), 1085- 1095. https://doi.org/10.1007/s10064-016-0899-x.
  19. Khalili, N. and Khabbaz, M.H. (1998), "A unique relationship for χ for the determination of the shear strength of unsaturated soils", Geotechnique, 48(5), 681-687. https://doi.org/10.1680/geot.1998.48.5.681.
  20. Leong, E.C. and Abuel-Naga, H. (2018), "Contribution of osmotic suction to shear strength of unsaturated high plasticity silty soil", Geomech. Energy Environ., 15, 65-73. https://doi.org/10.1016/j.gete.2017.11.002.
  21. Li, R.J., Liu, J.D., Yan, R, Zheng, W. and Shao, S.J. (2014), "Characteristics of structural loess strength and preliminary framework for joint strength formula", Water Sci. Eng., 7(3), 319-330. https://doi.org/10.3882/j.issn.1674-2370.2014.03.007.
  22. Liang, C.Y., Cao, C.S. and Wu, S.R. (2018), "Hydraulic-mechanical properties of loess and its behavior when subjected to infiltration-induced wetting", B. Eng. Geol. Environ., 77(1), 385-397. https://doi.org/10.1007/s10064-016-0943-x.
  23. Liang, Q.G., Li, J., Wu, X.Y. and Zhou, A.N. (2016), "Anisotropy of Q2 Loess in the Baijiapo Tunnel on the Lanyu Railway, China", B. Eng. Geol. Environ., 75(1), 109-124. https://doi.org/10.1007/s10064-015-0723-z.
  24. Lu, N. (2016), "Generalized soil water retention equation for adsorption and capillarity", J. Geotech. Geoenviron. Eng., 142(10), 04016051. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001524.
  25. Lu, X., Zhou, A.N., Shen, S.L., Li, J. and Sheng, D.C. (2020), "A micro-mechanical model for unsaturated soils based on DEM", Comput. Meth. Appl. Mech. Eng., 368, 113183. https://doi.org/10.1016/j.cma.2020.113183.
  26. Ma, F.L., Yang, J. and Bai, X.H. (2017), "Water Sensitivity and Microstructure of Compacted Loess", Transport. Geotech., 11, 41-56. https://doi.org/10.1016/j.trgeo.2017.03.003.
  27. Maleksaeedi, E. and Nuth, M. (2019), "Evaluation of capillary water retention effects on the development of the suction stress characteristic curve", Can. Geotech. J., 57(10), 1439-1452. https://doi.org/10.1139/cgj-2019-0326.
  28. Mei, Y., Hu, C.M., Yuan, Y.L., Wang, X.Y. and Zhao, N. (2016), "Experimental study on deformation and strength property of compacted loess", Geomech. Eng., 11(1), 161-175. https://doi.org/10.12989/gae.2016.11.1.161.
  29. Mu, Q.Y., Dong, H., Liao, H. J., Dang, Y.G. and Zhou, C. (2020), "Water-retention curves of loess under wetting drying cycles", Geotech. Lett., 10(1), 1-6. https://doi.org/10.1680/jgele.19.00025.
  30. Ng, C.W.W., Sadeghi, H. and Jafarzadeh. F. (2017), "Compression and shear strength characteristics of compacted loess at high suctions", Can. Geotech. J., 54(5), 690-699. https://doi.org/10.1139/cgj-2016-0347.
  31. Ng, C.W.W., Sadeghi, H., Jafarzadeh, F., Sadeghi, M., Zhou, C. and Baghbanrezvan, S. (2020), "Effect of microstructure on shear strength and dilatancy of unsaturated loess at high suctions", Can. Geotech. J., 57(2), 221-235. https://doi.org/10.1139/cgj-2018-0592.
  32. Oberg, A. and Sallfors, G. (1997), "Determination of shear strength parameters of unsaturated silts and sands based on the water retention curve", Geotech. Test. J., 20, 40-48. https://doi.org/10.1520/GTJ11419J.
  33. Pu, X., Wan, L. and Wang, P. (2021), "Initiation mechanism of mudflow-like loess landslide induced by the combined effect of earthquakes and rainfall", Nat Hazards, 105(3), 3079-3097. https://doi.org/10.1007/s11069-020-04442-6.
  34. Qiao, Y.F., Tuttolomondo, A., Lu, X.B., Laloui, L. and Ding, W.Q. (2020), "A generalised water retention model with soil fabric evolution", Geomech. Energy Environ., 25(2), 100205. https://doi.org/10.1520/GTJ20130034.
  35. Rahardjo, H., Satyanaga, A., Mohamed, H.,Yee Ip, S.C. and Shah, R.S. (2019), "Comparison of soil-water characteristic curves from conventional testing and combination of small-scale centrifuge and dew point methods", Geotech. Geol. Eng., 37(2), 659-672. https://doi.org/10.1007/s10706-018-0636-2.
  36. Satyanaga, A., Rahardjo, H., Koh, Z.H. and Mohamed, H. (2019), "Measurement of a soil-water characteristic curve and unsaturated permeability using the evaporation method and the chilled mirror method", J. Zhejiang Univ. Sci. A Appl. Phys. Eng., 20(5), 368-374. https://doi.org/10.1631/jzus.A1800593.
  37. Sheng, D.C., Zhou, A.N. and Fredlund. D.G. (2011), "Shear strength criteria for unsaturated soils", Geotech. Geol. Eng., 29(2), 145-15. https://doi.org/10.1007/s10706-009-9276-x.
  38. Sun, D.A., Gao, Y., Zhou, A.N. and Sheng, D.C. (2016), "Soil-water retention curves and microstructures of undisturbed and compacted Guilin lateritic clay", B. Eng. Geol. Environ., 75(2), 781-791. https://doi.org/10.1007/s10064-015-0765-2.
  39. Sun, D.A., Matsuoka, H., Yao, Y. and Ichihara W. (2000), "An elasto-plastic model for unsaturated soil in three-dimensional stresses", Soils Found., 40(3), 17-28. http://doi.org/10.3208/sandf.40.3_17.
  40. Sun, D.A., Sun, W.J. and Xiang, L. (2010), "Effect of degree of saturation on mechanical behaviour of unsaturated soils and its elastoplastic simulation", Comput. Geotech., 37(5), 678-688. https://doi.org/10.1016/j.compgeo.2010.04.006.
  41. Sun, D.A., Zhang, J.R., Gao, Y. and Sheng, D.C. (2016), "Influence of suction history on hydraulic and stress-strain behavior of unsaturated soils", Int. J. Geomech., 16(6), 1-9. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000602.
  42. Sun, H.Q., Masin, D., Najser, J., Nedela, V. and Navratilova, E. (2019), "Bentonite micro-structure and saturation evolution in wetting-drying cycles evaluated using ESEM, MIP and WRC measurements", Geotechnique, 69(8), 713-726. https://doi.org/10.1680/jgeot.17.p.253.
  43. Sun, W.J., Sun, D.A. and Liu, S.Q. (2014), "Hydro-mechanical behaviour of GMZ Ca-bentonite at high suctions", Chin. J. Geotech. Eng., 36(2), 346-353. https://doi.org/10.11779/CJGE201402012.
  44. Tekinsoy, M.A., Kayadelan, C., Keskin, M.S. and Soylemez, M. (2004), "An equation for predicting shear strength envelope with respect to matric suction", Comput. Geotech., 31(7), 589-593. https://doi.org/10.1016/j.compgeo.2004.08.001.
  45. Vanapalli, S.K., Fredlund, D.G., Pufahl, D.E. and Clifton A.W. (1996), "Model for the prediction of shear strength with respect to soil suction", Can. Geotech. J., 33(3), 379-392. https://doi.org/10.1139/t96-060.
  46. Wang, H.K., Qian, H., Gao, Y.Y. and Li, Y.B. (2020), "Classification and physical characteristics of bound water in loess and its main clay minerals", Eng. Geol., 265, 105394. https://doi.org/10.1016/j.enggeo.2019.105394.
  47. Wu, S.S., Zhou, A.N., Li, J., Kodikara, J., and Cheng, W.C. (2019) "Hydromechanical behaviour of overconsolidated unsaturated soil in undrained conditions", Can. Geotech. J., 56(11), 1609-1621. https://doi.org/10.1139/cgj-2018-0323.
  48. Xu, X. Zhao, C.G. and Cai, G.Q. (2018), "Shear strength of unsaturated soils considering capillary and adsorptive mechanisms", Rock Soil Mech., 39(6), 2059-2064, 2072. https://doi.org/10.16285/j.rsm.2017.1727.
  49. Zhang, C. and Lu, N. (2021), "Closure to "unified effective stress equation for soil" by Chao Zhang and Ning Lu", J. Eng. Mech., 147(2), 07020004. https://doi.org/10.1061/(ASCE)EM.1943-7889.0001893.
  50. Zhang, J.R., Niu, G., Li, X.C. and Sun, D.A. (2020), "Hydro-mechanical behavior of expansive soils with different dry densities over a wide suction range", Acta Geotech., 15(1), 265-278. https://doi.org/10.1007/s11440-019-00874-y.
  51. Zhang, J.R., Sun D.A. and Jiang, T. (2016), "Shear strength of weakly expansive soils and its prediction in a wide range of suction", Chin. J. Geotech. Eng., 38(6), 1064-1070. https://doi.org/10.11779/CJGE201606013.
  52. Zhang, J.W., Mu, Q.Y., Garg, A., Liu, F.L. and Cao, J. (2020), "Shear behavior of unsaturated intact and compacted loess: A comparison study", Environ. Geol., 79(3), 79. https://doi.org/10.1007/s12665-020-8820-0.
  53. Zhang, Y., Zhao, Y, Liu, J., Meng, T.Y., Shao, S.J. and She, S.T. (2021), "An experimental study on the deformation and strength characteristics of Q3 loess under a plain strain anisotropic consolidation condition", Adv. Civ. Eng., 1-13. https://doi.org/10.1155/2021/8813707.
  54. Zhao, C.G., Liu, Z.Z., Shi, P.X., Li, J., Cai, G.Q. and Wei, C.F. (2016), "Average soil skeleton stress for unsaturated soils and discussion on effective stress", Int. J. Geomech., 16(6), D4015006. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000610.
  55. Zhou, A.N., Huang, R.Q. and Sheng, D.C. (2016), "Capillary water retention curve and shear strength of unsaturated soils", Can. Geotech. J., 53(6), 974-987. https://doi.org/10.1139/cgj-2015-0322.
  56. Zhou, A.N. and Sheng, D.C. (2015), "An advanced hydro-mechanical constitutive model for unsaturated soils with different initial densities", Comput. Geotech., 63, 46-66. https://doi.org/10.1016/j.compgeo.2014.07.017.
  57. Zhou, A.N., Sheng, D.C., Sloan, S.W. and Gens, A. (2012), "Interpretation of unsaturated soil behavior in the stress-saturation space. I: Volume change and water retention behaviors", Comput. Geotech., 43(3), 178-187. https://doi.org/10.1016/j.compgeo.2012.04.010.
  58. Zhou, A.N., Wu, S.S., Li, J., and Sheng, D.C. (2018), "Including degree of capillary saturation into constitutive modelling of unsaturated soils", Comput. Geotech., 95(10), 82-98. https://doi.org/10.1016/j.compgeo.2017.09.017.