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Study on the Deterioration Mechanism of Subway Shield Tunnel Structure
Based on the Full-scale Test
(1. Department of Civil Engineering, Hangzhou City University, Hangzhou 310015; 2. Key Laboratory of Safe Construction and Intelligent
Maintenance for Urban Shield Tunnels of Zhejiang Province, Hangzhou 310015; 3. School of Civil Engineering and Architecture,
Anhui University of Science &Technology, Huainan 232001; 4. Zhejiang Province Institute of Architectural Design and Research,
Hangzhou 310000; 5. School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093)
Abstract To investigate the differences in the deterioration behaviors of subway shield tunnels under various loading
conditions, the full-scale test was conducted to comparatively analyze the evolution patterns of segment deterioration under different load scenarios, summarizing the characteristics of shield tunnel structural deterioration. The results indicate that the primary impact of loading and unloading states on shield tunnel segments is the disruption of force equilibrium and alteration of constraint conditions, thereby changing the evolution process of deterioration.The convergence deformation and stress variations of segments exhibit entirely opposite trends under symmetric loading and unloading. In the final stage of asymmetric unloading, the maximum positive and negative convergences of segments occur at 90° and 180°, respectively, with bolt stress undergoing multiple polarizations. Concrete cracks concentrate near the bottom of the arch crown, distributed at a 45° angle. In the final stage of asymmetric surcharge loading, the maximum positive and negative convergences are located at 90° and 30°, respectively. Bolt stress follows a linear pattern, and concrete cracks first appear at the arch haunch corners and are distributed at a 180° angle.
Abstract：
To investigate the differences in the deterioration behaviors of subway shield tunnels under various loading
conditions, the full-scale test was conducted to comparatively analyze the evolution patterns of segment deterioration under different load scenarios, summarizing the characteristics of shield tunnel structural deterioration. The results indicate that the primary impact of loading and unloading states on shield tunnel segments is the disruption of force equilibrium and alteration of constraint conditions, thereby changing the evolution process of deterioration.The convergence deformation and stress variations of segments exhibit entirely opposite trends under symmetric loading and unloading. In the final stage of asymmetric unloading, the maximum positive and negative convergences of segments occur at 90° and 180°, respectively, with bolt stress undergoing multiple polarizations. Concrete cracks concentrate near the bottom of the arch crown, distributed at a 45° angle. In the final stage of asymmetric surcharge loading, the maximum positive and negative convergences are located at 90° and 30°, respectively. Bolt stress follows a linear pattern, and concrete cracks first appear at the arch haunch corners and are distributed at a 180° angle.
WEI Gang1,
2 XU Tianbao3 FENG Feifan4 MU Zhiyuan3 ZHANG Zhiguo5
.Study on the Deterioration Mechanism of Subway Shield Tunnel Structure
Based on the Full-scale Test[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(6): 182-190
2024, Vol. 61 