Abstract In order to obtain the change laws of the temperature load and structural internal force of a large-diame? ter shield-driven railway tunnel in uneven fire scenarios, first, using the software FDS the train fire model with ventilation in the fire area considered is established to research the distribution of temperature loads on the fired lining surface. Then using the software ANSYS the thermal mechanical coupling model with internal structure considered is established to focus on researching the deformation, temperature distribution and internal force change of the tunnel lining and internal structure. The results show that the fire occuring to the train in a single-tube double-track railway tunnel with ventilation in the fire area considered is an uneven fire scenario where the fire temperature load is at most 500 ℃ and the highest concrete temperature of the fired lining surface is up to 256 ℃ after being exposed to fire for 120 m. The vertical displacements of tunnel vault and bottom in fire conditions are smaller than those in non-fire conditions, the horizontal structural displacement increases slightly while the vertical displacement of track slab decreases, and the internal force of the partial structural sections changes significantly with maximum increase being nearly 1 times. The sections on the fired lining surface present a complex stress status with larger temperature stress in the local range influenced by the temperature.
Abstract：
In order to obtain the change laws of the temperature load and structural internal force of a large-diame? ter shield-driven railway tunnel in uneven fire scenarios, first, using the software FDS the train fire model with ventilation in the fire area considered is established to research the distribution of temperature loads on the fired lining surface. Then using the software ANSYS the thermal mechanical coupling model with internal structure considered is established to focus on researching the deformation, temperature distribution and internal force change of the tunnel lining and internal structure. The results show that the fire occuring to the train in a single-tube double-track railway tunnel with ventilation in the fire area considered is an uneven fire scenario where the fire temperature load is at most 500 ℃ and the highest concrete temperature of the fired lining surface is up to 256 ℃ after being exposed to fire for 120 m. The vertical displacements of tunnel vault and bottom in fire conditions are smaller than those in non-fire conditions, the horizontal structural displacement increases slightly while the vertical displacement of track slab decreases, and the internal force of the partial structural sections changes significantly with maximum increase being nearly 1 times. The sections on the fired lining surface present a complex stress status with larger temperature stress in the local range influenced by the temperature.
WANG Mingnian1,
2 HU Xiaoyue1,
2 TANG Xiongjun3 DONG Yucang1 etc
.Study on Temperature Loads and Structural Internal Force Characteristics of Large-diameter Shield-driven Railway Tunnels in a Fire Scenario[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(1): 1-9
2021, Vol. 58 