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Numerical investigation on the effect of cutterhead shapes on tunnel face stability

Research output: Contribution to journalArticleResearchpeer review

Authors

  • Bassam Mohammed Al-Washali
  • Kai Yao
  • Umashankaran Satchithananthan
  • Zhanyong Yao
  • Michael Beer

Research Organisations

External Research Organisations

  • Shandong University
  • Thamar University
  • Sanaa University
  • Norwegian University of Science and Technology (NTNU)
  • University of Liverpool
  • Tongji University

Details

Original languageEnglish
Article number106628
Number of pages17
JournalTunnelling and Underground Space Technology
Volume163
Early online date24 Apr 2025
Publication statusE-pub ahead of print - 24 Apr 2025

Abstract

The stability of tunnel faces under the stationary condition of an Earth Pressure Balance (EPB) machine is critical in tunnel construction. While extensive research has focused on the operational stability of tunnel faces, a significant gap remains in understanding the influence of cutterhead geometry on face stability under stationary phases. This study employs three-dimensional (3D) Finite Element (FE) analysis to investigate tunnel face stability in clay and sandy soils, emphasizing the effect of cutterhead opening area ratio (COA), cutterhead shape, and tunnel cover depth (C/D) on stability under stationary conditions. Three distinct cutterhead shapes, exhibiting varying COAs (35 %, 40 %, and 45 %), were analysed across a range of cover depths from 0.5D to 4.0D (D represents the tunnel diameter). The results indicate that larger COAs (45 %) significantly increase soil displacement and instability risks, particularly in clay soils, with critical displacements occurring after reductions of up to 40 % in support pressure. In contrast, sandy soils demonstrated enhanced stability even with larger COAs. Furthermore, the study revealed a significant influence of cutterhead design on soil displacement and support pressure. Cutterhead shape 3, characterized by symmetrical openings and a large central panel, exhibited superior performance, minimizing soil displacement and requiring up to 20 % less support pressure compared to other cutterhead shapes investigated in this study. The cover depth in the three shapes was found to influence stability, with deeper tunnels (C/D = 4.0D) at various COAs experiencing greater displacement and requiring higher support pressures, especially in clay soils. Stress distribution analysis revealed that increased COA and larger cover depths contribute to higher horizontal stress, which exacerbates face instability. Additionally, clay soils exhibited a higher propensity for instability compared to sandy soils, particularly under conditions of larger COAs and deeper cover depths. This research provides a novel approach to optimizing EPB machine performance by considering face stability in the cutterhead opening areas. The findings offer valuable insights for tunnel boring machine (TBM) design and operational planning in various ground conditions.

Keywords

    Cutterhead open ratio, Cutterhead shape, EPB shield tunnel, Finite element method, Sinkhole, Tunnel face stability

ASJC Scopus subject areas

Cite this

Numerical investigation on the effect of cutterhead shapes on tunnel face stability. / Al-Washali, Bassam Mohammed; Yao, Kai; Satchithananthan, Umashankaran et al.
In: Tunnelling and Underground Space Technology, Vol. 163, 106628, 09.2025.

Research output: Contribution to journalArticleResearchpeer review

Al-Washali, B. M., Yao, K., Satchithananthan, U., Yao, Z., Tawfek, A. M., Pan, Y., & Beer, M. (2025). Numerical investigation on the effect of cutterhead shapes on tunnel face stability. Tunnelling and Underground Space Technology, 163, Article 106628. Advance online publication. https://doi.org/10.1016/j.tust.2025.106628
Al-Washali BM, Yao K, Satchithananthan U, Yao Z, Tawfek AM, Pan Y et al. Numerical investigation on the effect of cutterhead shapes on tunnel face stability. Tunnelling and Underground Space Technology. 2025 Sept;163:106628. Epub 2025 Apr 24. doi: 10.1016/j.tust.2025.106628
Al-Washali, Bassam Mohammed ; Yao, Kai ; Satchithananthan, Umashankaran et al. / Numerical investigation on the effect of cutterhead shapes on tunnel face stability. In: Tunnelling and Underground Space Technology. 2025 ; Vol. 163.
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AU - Al-Washali, Bassam Mohammed

AU - Yao, Kai

AU - Satchithananthan, Umashankaran

AU - Yao, Zhanyong

AU - Tawfek, Abdullah M.

AU - Pan, Yutao

AU - Beer, Michael

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