Abstract Due to the closed space, tunnel fires have the characteristics of rapid temperature rise, long duration, uneven temperature distribution and so on. It is very easy to cause thermal damage to the tunnel lining, resulting in significant attenuation of structural mechanical properties, which seriously affects the safety and reliability of tunnel operation. In order to solve this problem, a three-dimensional finite element model is established based on a large diameter shield tunnel project, and the temperature field distribution, structural deformation and internal force under different fire scenarios are studied.The study concluded that: (1) Under the influence of thermal boundary conditions, the distribution of temperature field in tunnel appears obvious partition phenomenon in fire; (2) The deformation mode of the lining ring in fire is determined by load effect and thermal expansion effect, and the two factors are affected by fire scale and fire time; (3) In the area affected by the fire source, the stress on both sides of each seg? ment is large, and the inner rebar makes a great contribution to the mechanical performance of structure. However,with the development of fire, the stress distribution of segments and rebars changes significantly.
Abstract：
Due to the closed space, tunnel fires have the characteristics of rapid temperature rise, long duration, uneven temperature distribution and so on. It is very easy to cause thermal damage to the tunnel lining, resulting in significant attenuation of structural mechanical properties, which seriously affects the safety and reliability of tunnel operation. In order to solve this problem, a three-dimensional finite element model is established based on a large diameter shield tunnel project, and the temperature field distribution, structural deformation and internal force under different fire scenarios are studied.The study concluded that: (1) Under the influence of thermal boundary conditions, the distribution of temperature field in tunnel appears obvious partition phenomenon in fire; (2) The deformation mode of the lining ring in fire is determined by load effect and thermal expansion effect, and the two factors are affected by fire scale and fire time; (3) In the area affected by the fire source, the stress on both sides of each seg? ment is large, and the inner rebar makes a great contribution to the mechanical performance of structure. However,with the development of fire, the stress distribution of segments and rebars changes significantly.
ZHANG Tingrui
.Research on Thermal Properties and Mechanical Behaviors of Large Shield Tunnel in Fire[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(5): 202-211
2022, Vol. 59 