Effect of Nanoclay-Depended Treatment on the Mechanical Behavior of a Collapsible Soil

Document Type : Regular Paper

Authors

1 Civil Engineering Department, Al-Iraqia University, Baghdad, Iraq

2 Directorate of Education, Ministry of Education, Najaf, Iraq

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

Abstract

The research investigates the effects of adding nanoclay on the shear strength properties of two gypseous sand soils. The soil samples were taken from the cities of Tikrit (55% gypsum) and Al-Najaf (29% gypsum). A direct shear test was used to examine soil specimens in dry conditions and immediately after a saturation procedure. The distributed soil specimens were remolded in the direct shear box to achieve a specific density. The shear speed was 1.0 mm/min. For both soil samples, there are different added nanoclay contents, 0, 2, 5, and 7%. Three levels of normal stress are applied, 25, 50, and 100 kPa on each soil specimen. The results state that there is a significant decrease in the angle of internal friction with saturation for both soil samples due to the gypsum solution in these soils. The resulting saturated F is significantly lower than the reported mean values in the literature. The F is recovered by adding nanoclay content up to 5% worthily. A mathematical model correlates the values of F and the percentage of nanoclay using a regression analysis with restricting gypsum content (29-55%) and nanoclay (≥ 0%) in saturation conditions.

Graphical Abstract

Effect of Nanoclay-Depended Treatment on the Mechanical Behavior of a Collapsible Soil

Highlights

  • The paper investigates the effect of adding nanoclay on the shear strength parameters of two gypseous sand soils. The soil samples are from Al-Najaf city (29% gypsum) and Tikrit city (55% gypsum). The soil specimens are tested dry and immediately after a saturation process using a direct shear box.
  • The resulting values of the shear strength parameters are compared with those available for the city.
  • The apparent cohesion is neglected due to its effect on the saturation process.
  • After a saturation process, there is about a 25% decrease in the values of the internal friction angle (F) for both soils.
  • With the addition of a nanoclay, there is an increase in F. The percentage increase depends on the gypsum content.
  • The rise in F is 17 to 32% for 29 and 55% of gypsum, respectively. The significant increase in F is within 5% nanoclay.
  • The resulting saturated F is significantly lower than the reported mean values in the literature, but with the addition of nanoclay, the measured values are close to those reported.
  • Within no significant effect of the gypsum within the range of 29 to 55%, an equation (3) relating the F with nanoclay is adopted using a regression with a good correlation (R2=0.82).

Keywords

Main Subjects


[1]     Ian J, Chris DF R. Chapter 32 Collapsible soils. ICE Man. Geotech. Eng., Thomas Telford Ltd; 2012, p. 391–411.
[2]     Aldarraji S, Ganjian N. Interaction of Curing and Soaking on Collapse Potential of Nanoclay-Treated Soil. J Eng Sustain Dev 2024;28:480–5.
[3]     Mahmood MS, Abrahim MJ. A review of collapsible soils behavior and prediction. IOP Conf. Ser. Mater. Sci. Eng., vol. 1094, IOP Publishing; 2021, p. 12044.
[4]     Abdalhusein MM, Ali Akhtarpour MSM. Effect of wetting process with presence of matric suction on unsaturated gypseous sand soils. J Southwest Jiaotong Univ 2019;54.
[5]     Mahmood MS, Akhtarpour A, Almahmodi R, Husain MMA. Settlement assessment of gypseous sand after time-based soaking. IOP Conf. Ser. Mater. Sci. Eng., vol. 737, IOP Publishing; 2020, p. 12080.
[6]     Mahmood MS, Aziz LJ, Al-Gharrawi A. Settlement behavior of sand soil upon soaking process. Int J Civ Eng Technol India 2018;9:860–9.
[7]     Mahmood MS, Al-Baghdadi WH, Rabee AM, Almahbobi SA. Reliability of shear-box tests upon soaking process on the sand soil in al-najaf city. Key Eng Mater 2020;857:212–20.
[8]     Saleh SM, Mahmood MS. Behavior of load-settlement-time for short-term wetting in unsaturated test of Al-Najaf gypseous soil. AIP Conf. Proc., vol. 2787, AIP Publishing; 2023.
[9]     Mahmood MS, Saleh SM. Stress-dependent soil-water relationship for unsaturated gypseous sand. AIP Conf. Proc., vol. 3249, AIP Publishing; 2024.
[10]   Abrahim MJ, Mahmood MS. Effect of wetting progress on the potential collapse of gypseous sand using modified oedometer. Int J Eng Trans C Asp 2021;34:2636–41.
[11]    Abrahim MJ, Mahmood MS. Water Volume Change Due to Wetting of Unsaturated Gypseous Sand Using Modified Oedometer. IOP Conf. Ser. Earth Environ. Sci., vol. 856, IOP Publishing; 2021, p. 12048.
[12]   Mahmood MS, Abrahim MJ. Sensitivity of unsaturated tests results for time-based remolded gypseous sand specimens. AIP Conf. Proc., vol. 2864, AIP Publishing; 2024.
[13]   Abdalhusein MM, Mahmood MS, Saleh SM, Almahmodi R. Reliability of Soil Water Characteristics Curve under Different Normal Stresses for Unsaturated Sand. BIO Web Conf., vol. 97, EDP Sciences; 2024, p. 41.
[14]   Mahmood MS, Jamal M. RELAIBILITY ASSESSMENT OF THE SOIL-WATER- RETENTION FOR RELAIBILITY ASSESSMENT OF THE SOIL - WATER - RETENTION FOR UNSATURATED SAND SOILS 2024.
[15]   Abdalhusein MM, Akhtarpour A, Almahmodi R, Mahmood MS. Investigation of Shear Strength Parameters for Gypseous Soils Using a Modified Apparatus of Triaxial Test. Int. Conf. Geotech. Eng., Springer; 2022, p. 317–30.
[16]   Aldarraji SA, Ganjian N, Mahmood MS. Mechanical Behavior of Pre-Test-Curing Nanoclay-Treated Gypseous Sand. BIO Web Conf., vol. 97, EDP Sciences; 2024, p. 40.
[17]   Hayal AL, Al-Gharrawi AMB, Fattah MY. Effect of nanomaterials on shear strength of gypseous soil. Kufa J Eng 2021;12:1–14.
[18]   Karkush MO, Al-Murshedi AD, Karim HH. Investigation of the Impacts of Nano-clay on the Collapse Potential and Geotechnical Properties of Gypseous Soils. Jordan J Civ Eng 2020;14.
[19]   Aldarraji SA, Ganjian N. Void Ratio Change for Nanoclay-Treated Gypsiferous Sand under Stress-Curing-Soaking Combination n.d.;d:2–10.
[20]   Mazaheri A, Delfani N, Komasi M, Nasiri M. Experimentally Investigation of Nano Clay Effects on Leaching and Self-healing Process of Cracked Clayey Soils. J Rehabil Civ Eng 2021;9:71–83.
[21]   Long L, Nasiri M, Amiri E. Optimal Preservation of Oil-Containing Sands Using Zeolite: A Physical and Chemical Analysis. J Geotech Geoenvironmental Eng 2024;150:4024121.
[22]   Mazaheri AR, Nasiri M, Javadi A, Amiri E. Stabilization of crude oil-contaminated Bushehr carbonate sand: physical and chemical study. Bull Eng Geol Environ 2024;83:373.
[23]   Altameemi ZA, Shafiqu QSM, Al-Taie AJ. Evaluation of Tikrit Dune Sand Soil Enhanced with CKD. E3S Web Conf., vol. 427, EDP Sciences; 2023, p. 1008.
[24]   Al-Obaidi AA, Alsalih D. Experimental Investigation of Capillary Rise in Unsaturated Gypseous Soils. E3S Web Conf., vol. 427, EDP Sciences; 2023, p. 1016.
[25]   ASTM D422. Standard Test Method for Particle-Size Analysis of Soils. Astm 2007;D422-63:1–8.
[26]   ASTM. D854 - Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer. Astm D854 2000;2458000:1–7.
[27]   Methods ST. Standard Test Methods for Chemical Analysis of Limestone , Quicklime , and Hydrated 2020. doi:10.1520/C0025-19.1.
[28]   ASTM D698-12(2021). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort. ASTM Int 2012;3.
[29]   Al-Mamoori SK, Kareem SL, Al-Maliki LA, El-Tawil K. Geotechnical maps for angle of internal friction of An-Najaf Soil-Iraq using GIS. Wasit J Eng Sci 2020;8.