Experimental and Numerical Investigation of the Effect of Nanoclay Addition on Excavation Stability

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Geotechnics, Facultyof Civil Engineering, Islamic Azad University, Islamshahr Branch, Islamshahr, I. R. Iran.

2 PhD Candidate of Geotechnics, Faculty of Civil Engineering, Islamic Azad University, Islamshahr Branch, Islamshahr, I. R. Iran.

Abstract

In this study, the main objective is investigating the effect of adding nanoclay on the stability of excavations. For this purpose, laboratory soil samples were prepared in two conditions: untreated and treated with different percentages of nanoclay (0%, 3%, and 5%), and subsequently tested. Then, a 10-meter-deep excavation model in the Velenjak area of Tehran was constructed at a smaller scale under both natural and nanoclay-stabilized conditions, and deformations were examined. In addition, numerical modeling of the target excavation was carried out using FLAC3D software to provide a comparison between the laboratory and numerical results. The findings indicated that the use of nanoclay significantly increases the factor of safety of excavation stability and reduces both horizontal and vertical displacements. The optimum nanoclay content was found to be 3%, as higher percentages showed no significant improvement and, in some cases, even had negative effects on soil behavior. This behavior was observed in both numerical and experimental models, with good agreement between them. Also, the influence of nanoclay on soil strength as a novel material was compared with cement as a conventional stabilizer. The advantages of nanoclay-particularly its environmentally friendly nature compared to cement-were highlighted as strong reasons to prefer nanoclay and, more generally, nanomaterials. Overall, the results demonstrated that applying nanoclay as a stabilizing additive can serve as an effective solution for urban excavation projects.

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Main Subjects

References

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History

  • Receive Date: 28 August 2025
  • Revise Date: 05 December 2025
  • Accept Date: 16 December 2025

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