Face stability analysis for an EPB shield sunnel by using two-dimension finite element limit analysis (Case study: Ahwaz metro tunnel line 1)

Entezar, MR; Eslami Haghighat, Abbas; Hajihassani, Mohsen

doi:10.22065/jsce.2024.437451.3335

Face stability analysis for an EPB shield sunnel by using two-dimension finite element limit analysis (Case study: Ahwaz metro tunnel line 1)

Document Type : Original Article

Authors

MR Entezar ¹

Abbas Eslami Haghighat ²

Mohsen Hajihassani ¹

¹ Urmia University

² faculty member

10.22065/jsce.2024.437451.3335

Abstract

In recent years, earth pressure balance (EPB) tunnel boring machines (TBMs) have become widely used for tunnel excavation. Proper design of TBMs requires detailed study and examination of the soil conditions around the excavation site. A key parameter in these studies is the stability pressure of the working face, which is applied to the soil mass by the TBM to prevent collapse and uplift of the soil. This study analyses and investigates the stability pressure of the working face of Ahvaz metro tunnel line 1 using finite element limit analysis and two-dimensional modelling. This method, which combines limit analysis and finite element meshing, yields highly accurate results. The average of the upper and lower limits obtained can serve as a reliable approximation of the actual load. In the collapse state, the percentage difference between the upper and lower limits is typically less than 0.3%, and in the uplift state, it is generally below 2%. These results suggest that the two-dimensional finite element limit analysis method is a highly suitable initial approach for estimating the stability pressure of the working face. These results suggest that the two-dimensional finite element limit analysis method is a highly suitable initial approach for estimating the stability pressure of the working face.

Keywords

Finite Element Limit Analysis

Stability Pressure

Upper Bound

Lower Bound

2D Analysis

Subjects

Tunnel Engineering

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