Thermo-mechanical analysis of fire effects on the structural performance of shield tunnels. (February 2023)

• Record Type: Journal Article
• Authors: Shen, Yi; Zhu, Hehua; Yan, Zhiguo; Zhou, Long; Zhang, Tong; Men, Yanqing; Lu, Yong
• Is Part Of: Tunnelling and underground space technology. Volume 132(2023)
• Publication Date: 2023-02
• Subjects: Fire effect -- Shield tunnel -- Thermo-mechanical model -- Structural performance -- Numerical analysis; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2022.104885
• Languages: English
• ISSNs: 0886-7798

Abstract

Graphical abstract: Highlights: A comprehensive model of the tunnel segmental ring in fire is established. The model incorporates thermo-mechanical properties of tunnel structure in fire. Validation of numerical results against experimental data shows good agreement. Parametric studies are conducted to investigate the diverse fire effects. Abstract: Investigating fire effects is a continuing endeavour in the research and practice communities concerned with the design and safety of shield tunnels. This paper aims to provide a comprehensive model for the assessment of structural safety of a shield tunnel segmental ring exposed to fire. A thermo-mechanical model for assembled shield tunnel structure in fire is developed to provide a basis for a holistic analysis by incorporating tunnel lining segments and longitudinal joints, as well as improved predictions for the temperature, stress and deformation distributions in the tunnel structure. Validation of the numerical results against experimental data shows satisfactory agreement. Parametric studies are subsequently conducted to investigate the effects of spalling, buried depth and cooling-off phases on the fire behaviour of the shield tunnel. The results show that the damage and failure of a tunnel lining structure under high temperature are mainly due to the combined action of internal thermal expansion force and thermal stress. Spalling leads to the loss of a key "insulation" layer of a tunnel lining structure. On the other hand, the constraint of strata on the tunnel structure under high temperature not only restrains the deformation of key parts of the structure, but also helps offset the adverse effect of load on the structure through elastic resistance.