Research Article

A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran

Volume: 16 Number: 4 October 14, 2026
TR EN

A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran

Abstract

This study investigates the stability of the Dorud–Khorramabad railway tunnel site (km 90+155) using rock classification systems and limit equilibrium methods. The tunnel site was divided into five geotechnical units (Ta1, Tb1, Ta2, Tb2, and Tc) based on the Basic Geotechnical Description (BGD) method. The lithology includes limestone, marly shale, and two crushed zones, with prevalent discontinuities such as joints and bedding planes. The uniaxial compressive strength (UCS) of intact rocks ranges from 7 to 60 MPa, excluding weaker crushed zones. The rock mass discontinuities have been studied based on surface surveys and boreholes drilling, and engineering rock mass classifications have been carried out. Rock Quality Designation (RQD) values range between 10 and 70, indicating poor to medium quality. Rock Mass Rating (RMR) qualifies the rock mass as poor rock for site scores between 25 and 43, while the Q-system classifies the units as extremely weak to weak (0.059–1.625). Geological Strength Index (GSI) values vary from 20 to 60, confirming very poor to medium quality. Wedge analysis using Unwedge v3.0 revealed safety factors from 0.001 to 2.331. Wedges with factors below 1.5 can be stabilized using rock bolts. The findings show good agreement between both analysis methods, supporting the reliability of the results for tunnel stability assessment.

Keywords

Engineering properties, Tunnel site, Rock mass classification, limit equilibrium analysis

References

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APA
Soleimani, H., Fereidooni, D., & Cihangir, F. (2026). A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran. Karadeniz Fen Bilimleri Dergisi, 16(4), 1673-1694. https://doi.org/10.31466/kfbd.1857788
AMA
1.Soleimani H, Fereidooni D, Cihangir F. A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran. KFBD. 2026;16(4):1673-1694. doi:10.31466/kfbd.1857788
Chicago
Soleimani, Hossein, Davood Fereidooni, and Ferdi Cihangir. 2026. “A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran”. Karadeniz Fen Bilimleri Dergisi 16 (4): 1673-94. https://doi.org/10.31466/kfbd.1857788.
EndNote
Soleimani H, Fereidooni D, Cihangir F (October 1, 2026) A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran. Karadeniz Fen Bilimleri Dergisi 16 4 1673–1694.
IEEE
[1]H. Soleimani, D. Fereidooni, and F. Cihangir, “A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran”, KFBD, vol. 16, no. 4, pp. 1673–1694, Oct. 2026, doi: 10.31466/kfbd.1857788.
ISNAD
Soleimani, Hossein - Fereidooni, Davood - Cihangir, Ferdi. “A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran”. Karadeniz Fen Bilimleri Dergisi 16/4 (October 1, 2026): 1673-1694. https://doi.org/10.31466/kfbd.1857788.
JAMA
1.Soleimani H, Fereidooni D, Cihangir F. A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran. KFBD. 2026;16:1673–1694.
MLA
Soleimani, Hossein, et al. “A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran”. Karadeniz Fen Bilimleri Dergisi, vol. 16, no. 4, Oct. 2026, pp. 1673-94, doi:10.31466/kfbd.1857788.
Vancouver
1.Hossein Soleimani, Davood Fereidooni, Ferdi Cihangir. A Comparative Analysis of Experimental and Limit Equilibrium Methods for Stability Analysis of the Dorud–Khorramabad Railway Tunnel Site, Lorestan, Iran. KFBD. 2026 Oct. 1;16(4):1673-94. doi:10.31466/kfbd.1857788