Mechanical Behavior and Stability Control of Metro Station Tunnel Group Intersections During Construction |
| ShangYue Lin |
| China Railway 14th Bureau Group Co., Ltd., Jinan，Shandong 250101, China |
| Abstract：Metro station tunnel groups are often characterized by dense intersection layouts, which introduce unique challenges such as intricate stress distributions, difficult construction operations, and heightened vulnerability to safety hazards. To address these issues, this study takes the tunnel group of Nanning Qingxiushan Metro Station as a case study, establishing a three-dimensional numerical model that is calibrated with on-site monitoring data. The research focuses on investigating the mechanical response mechanisms of the tunnel group during construction, including surrounding rock deformation patterns, stress evolution laws, and plastic zone development characteristics. Special emphasis is placed on analyzing the dynamic mechanical behavior of the left-line tunnel during its connection with the cross-passage. The results indicate that the tunnel structure is significantly affected by the eccentric load from the upper foundation pit: the surrounding rock at the intersection of the tunnel on the eccentrically loaded side exhibits substantially larger displacement and stress compared to the non-eccentrically loaded side. Additionally, the excavation of the cross-passage induces significant disturbance to the intersection area, resulting in concentrated plastic strain. When the left-line tunnel is breached to connect with the cross-passage, tensile stress is generated at the vault of the breached lining, and severe stress concentration occurs at the arch shoulder and arch foot. The implementation of targeted deformation control measures is proven effective in ensuring the structural stability of the tunnel group. This research provides technical support for the design and construction of similar metro tunnel group intersection projects. |
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Keywords：metro station tunnel group; intersection structure; construction mechanical response; numerical analysis;stability control
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