Effect of Matric Suction on Deformation of Gypseous Sand Using Modified Oedometer

Document Type : Original Article

Authors

Civil Engineering Department, University of Kufa, Al-Najaf, Iraq

Abstract

Gypsum is a soluble material, and it is one of the problematic components in the soil in the west of Iraq. Al-Najaf is one of the governorates in Iraq which suffers from the gypsum content in different levels. The soil of the city is mainly sand-sized particles bonded by different percentages of gypsum. The main problem of this component is the dissolution upon the wetting process. This paper investigates the effect of decreasing the matric suction (wetting) on soil deformation under a specific stress level. The investigation includes three matric suctions of (50, 20, and 0 kPa) under three net normal stresses of 221 kPa, 442 kPa and 885 kPa respectively. The soil specimens are remolded to 95% of the maximum dry density from the proctor test. A modified Oedometer setup is used to perform the tests, including the application of air and water pressures up to achieve the specific matric suctions. The results revealed that the highest value of collapse potential (CP) is under the stress of 221kPa, and the greatest part of the CP is achieved prior to the saturation of the soil. This issue must be considered in the analysis and design of the foundation in unsaturated gypseous sandy soils.

Keywords

References

  1. Al-Shakerchy, M.S., "Geotechnical properties of al najaf city soil with emphasis on the infiltration and strength characteristics", (2007),
  2. Al-Saoudi, N.K. and Al-Shakerchy, M.S.M., "Statistical analysis of some geotechnical properties of najaf city", in Proceedings of International Geotechnical Conference. Vol. 3, (2010), 1173-1180.
  3. Scaffaro, R., Lopresti, F., Botta, L., Rigogliuso, S. and Ghersi, G., "Integration of pcl and pla in a monolithic porous scaffold for interface tissue engineering", Journal of the Mechanical Behavior of Biomedical Materials, Vol. 63, (2016), 303-313, doi. https://doi.org/10.1016/j.jmbbm.2016.06.021
  4. Chekired, M., "A modified oedometer apparatus for experimentally obtaining the soil-water retention curve", Proceedings of: Geovancouver Conference, (2016).
  5. Ruge, J., Cunha, R. and Mašín, D., "Results of unsaturated tests on metastable soils", in Proceedings 1st Pan-American Conference on Unsaturated Soils, PanAmUNSAT. (2013), 469-474.
  6. Aldaood, A., Bouasker, M. and Al-Mukhtar, M., "Effect of long-term soaking and leaching on the behaviour of lime-stabilised gypseous soil", International Journal of Pavement Engineering, Vol. 16, No. 1, (2015), 11-26,
  7. Asghari, S., Ghafoori, M. and Tabatabai, S.S., "Changes in chemical composition and engineering properties of gypseous soils through leaching: An example from mashhad, iran", Bulletin of Engineering Geology and the Environment, Vol. 77, No. 1, (2018), 165-175.
  8. Haeri, S.M., Beigi, M., Saberi, S. and Garakani, A.A., "Study on the stress path dependency of collapse behavior of gorgan loess implementing unsaturated oedometer devices", in E3S Web of Conferences, EDP Sciences. Vol. 9, (2016), 14019.
  9. Abdalhusein, M.M., Akhtarpour, A. and Mahmood, M.S., "Effect of soaking on unsaturated gypseous sand soils", International Journal of Civil Engineering and Technology, Vol. 10, No. 5, (2019), 550-558.
  10. Abdalhusein, M.M. and Ali Akhtarpour, M.S., "Effect of wetting process with presence of matric suction on unsaturated gypseous sand soils", Journal of Southwest Jiaotong University, Vol. 54, No. 5, (2019).
  11. Liu, C., He, P. and Huang, Q., "Influence of matrix suction on engineering properties of unsaturated soil", in 2011 Second International Conference on Mechanic Automation and Control Engineering, IEEE. (2011), 2250-2253.
  12. Fattah, M.Y., Al-Shakarchi, Y.J. and Al-Numani, H.N., "Long term deformation of some gypseous soils", Engineering and Technology Journal, Vol. 26, No. 12, (2008), 1461-1483, doi.
  13. Fattah, M.Y., Al-Ani, M.M. and Al-Lamy, M.T., "Studying collapse potential of gypseous soil treated by grouting", Soils and Foundations, Vol. 54, No. 3, (2014), 396-404, doi: 10.1016/j.sandf.2014.04.008.
  14. Mahmood, M., "Effect of soaking on the compaction characteristics of al-najaf sand soil", Kufa Journal of Engineering, Vol. 9, No. 2, (2018), 1-12, doi: 10.30572/2018/kje/090201.
  15. Mahmood, M.S., Akhtarpour, A., Almahmodi, R. and Husain, M.M.A., "Settlement assessment of gypseous sand after time-based soaking", in IOP Conference Series: Materials Science and Engineering, IOP Publishing. Vol. 737, No. 1, (2020), 012080.
  16. Mahmood, M.S., Aziz, L.J. and Al-Gharrawi, A., "Settlement behavior of sand soil upon soaking process", International Journal of Civil Engineering and Technology, India, Vol. 9, No. 11, (2018), 860-869.
  17. Mahmood, M.S., "Prediction of discrepancy settlement behaviour of sand soils", Applied Research Journal, Iran, Vol. 4, No. 2, (2018), 30-37.
  18. Mahmood, M.S. and Abrahim, M.J., "A review of collapsible soils behavior and prediction", in IOP Conference Series: Materials Science and Engineering, IOP Publishing. Vol. 1094, No. 1, (2021), 012044.
  19. Zimbardo, M., Ercoli, L. and Megna, B., "The open metastable structure of a collapsible sand: Fabric and bonding", Bulletin of Engineering Geology and the Environment, Vol. 75, No. 1, (2016), 125-139, doi. https://doi.org/10.1007/s10064-015-0752-7
  20. Mahmood, M.S., "Effect of time-based soaking on shear strength parameters of sand soils", Applied Research Journal, Vol. 3, No. 5, (2017), 142-149.
  21. Mahmood, M.S., Al-Baghdadi, W.H., Rabee, A.M. and Almahbobi, S.H., "Reliability of shear-box tests upon soaking process on the sand soil in al-najaf city", in Key Engineering Materials, Trans Tech Publ. Vol. 857, (2020), 212-220.
  22. Mahmood, M., Almahbobi, S., Rabee, A., Rahim, A., Naama, M. and Mohammed, M., "Reliable prediction of structure settlement in al-najaf city using laboratory testing", in IOP Conference Series: Materials Science and Engineering, IOP Publishing. Vol. 888, No. 1, (2020), 012013.
  23. Lloret, A. and Alonso, E., "Consolidation of unsaturated soils including swelling and collapse behaviour", Géotechnique, Vol. 30, No. 4, (1980), 449-477.
  24. Fredlund, D.G. and Rahardjo, H., "Soil mechanics for unsaturated soils, John Wiley & Sons, (1993).
  25. ISLAM, M., "Selection of intermodal conductivity averaging scheme for unsaturated flow in homogeneous media", International Journal of Engineering, Vol. 28, No. 4, (2015), 490-498, doi: 10.5829/idosi.ije.2015.28.04a.01.
  26. Safarzadeh, Z. and Aminfar, M.H., "Experimental and numerical modeling of the effect of groundwater table lowering on bearing capacity of shallow square footings", International Journal of Engineering, Vol. 32, No. 10, (2019), 1429-1436, doi: 10.5829/ije.2019.32.10a.12.
  27. Hayal, A., Al-Gharrawi, A. and Fattah, M., "Collapse problem treatment of gypseous soil by nanomaterials", International Journal of Engineering, Vol. 33, No. 9, (2020), 1737-1742, doi: 10.5829/ije.2020.33.09c.06.
  28. Pells, P., Robertson, A., Jennings, J. and Knight, K., A guide to construction on or with materials exhibiting additional settlement due to" collapse" of grain structure. 1975.
International Journal of Engineering
Volume 34, Issue 12
TRANSACTIONS C: Aspects
December 2021
Pages 2636-2641

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