Abstract To study the impact of bolt failure on the dynamic response of a shield tunnel to train loads and to clarify the action of linings under bolt failure, a three-dimensional refined numerical model was established based on a domestic shield tunnel project. The explicit dynamic time-history method was used to calculate and analyze the tunnel's dynamic response. The results show that: (1) Under train vibration load, the failure of segment bolts increases the peak acceleration of the tunnel's internal structure by 29.4% and the segment peak acceleration by 64.8%, indicating that bolt failure reduces the stiffness of the tunnel lining structure, thereby exacerbating the tunnel structure's dynamic response. (2) When bolts fail, the peak acceleration of the internal structure of a double-layer lining tunnel is 13.3% lower than that of a single-layer lining tunnel, and the peak acceleration of the segments is 54.1% lower, indicating that the double-layer lining shield tunnel has a weaker dynamic response under train vibration load. This shows that secondary lining can buffer the impact force of trains on the tunnel structure. (3) Under train load, the maximum peak acceleration of segments is 17.2% of the peak acceleration of the internal structure, indicating that the train load is mainly borne by the internal structure. (4) Bolt failure has almost no impact on the peak stress and displacement at the connection between segments and the internal structure, suggesting that stress and displacement at the connection point under train load are not sensitive to bolt failure. (5) The application of secondary lining reduces the peak acceleration at the connection between segments and the internal structure by 57.1%, displacement by 22.2%, and maximum principal stress by 21.4%, indicating that secondary lining can reduce the dynamic response at the connection under train load, protecting the tunnel structure.
Abstract：
To study the impact of bolt failure on the dynamic response of a shield tunnel to train loads and to clarify the action of linings under bolt failure, a three-dimensional refined numerical model was established based on a domestic shield tunnel project. The explicit dynamic time-history method was used to calculate and analyze the tunnel's dynamic response. The results show that: (1) Under train vibration load, the failure of segment bolts increases the peak acceleration of the tunnel's internal structure by 29.4% and the segment peak acceleration by 64.8%, indicating that bolt failure reduces the stiffness of the tunnel lining structure, thereby exacerbating the tunnel structure's dynamic response. (2) When bolts fail, the peak acceleration of the internal structure of a double-layer lining tunnel is 13.3% lower than that of a single-layer lining tunnel, and the peak acceleration of the segments is 54.1% lower, indicating that the double-layer lining shield tunnel has a weaker dynamic response under train vibration load. This shows that secondary lining can buffer the impact force of trains on the tunnel structure. (3) Under train load, the maximum peak acceleration of segments is 17.2% of the peak acceleration of the internal structure, indicating that the train load is mainly borne by the internal structure. (4) Bolt failure has almost no impact on the peak stress and displacement at the connection between segments and the internal structure, suggesting that stress and displacement at the connection point under train load are not sensitive to bolt failure. (5) The application of secondary lining reduces the peak acceleration at the connection between segments and the internal structure by 57.1%, displacement by 22.2%, and maximum principal stress by 21.4%, indicating that secondary lining can reduce the dynamic response at the connection under train load, protecting the tunnel structure.
WANG Zhiyuan1 YANG Hao2 LIN Gang1 LIAN Zhengzhou2 YU Bo1
.Analysis of the Impact of Connecting Bolts on the Vibration Response of Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(4): 172-179
2024, Vol. 61 