International Journal of Transportation Engineering

International Journal of Transportation Engineering

Seismic Reliability Analysis of the Koohrang-III Tunnel Using Response Surface Methodology, Hasofer–Lind Reliability Analysis, and Finite Element Modeling

Articles in Press

Document Type : Research Paper

Authors
Mahmoud keyvani 1
Reza Akbari 2
Alireza Zareei 1
Alireza Shahidi 3
1 Dept. of Engineering, Isfahan Branch, Islamic Azad University, Isfahan, Iran
2 Road Maintenance and Transportation Organization, Tehran, Iran
3 Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
10.22119/ijte.2026.587045.1731
Abstract
This study presents a robust framework for assessing the seismic reliability of the Koohrang-III water transmission tunnel by accounting for the complex soil-structure interaction (SSI) phenomenon. A high-fidelity finite element-based numerical model was developed to simulate the tunnel’s dynamic behavior under various seismic loading conditions. To evaluate structural reliability, this research integrates the Response Surface Method (RSM) with the Hasofer–Lind algorithm, providing a computationally efficient approach to quantify performance. Six distinct strong ground motions were applied during nonlinear time-history analyses to extract critical design parameters, specifically the thrust force and bending moments. The results demonstrate that the tunnel’s structural reliability is highly sensitive to the analyzed loading parameters. Specifically, the thrust force exhibited the highest failure probability at approximately 37.5%, while the bending moment showed the lowest at roughly 2%. These findings highlight the necessity of reliability-based assessments in enhancing tunnel seismic safety protocols and optimizing structural design against earthquake-induced hazards.
Keywords
Seismic reliability, Tunnel, Soil-structure interaction, Response surface method, Hasofer&ndash
Lind method
International Journal of Transportation Engineering

Articles in Press, Accepted Manuscript
Available Online from 19 September 2026