Abstract
The Taixi Railway Heping Tunnel traverses fault fracture zones characterized by highly fractured rock masses in lithological contact zones, well-developed intrusive and fault structures, extremely poor surrounding rock stability, and a strongly water-rich environment, which renders water inrush and mud burst highly probable and poses significant construction safety risks. To ensure excavation progress and construction safety, advanced analysis of tunnel surrounding rock conditions is performed using Tunnel Seismic Prediction (TSP) and ground-penetrating radar (GPR) technologies during construction through water-rich strata, providing technical and safety guidance for tunnel face excavation. Advanced water drainage measures are implemented to overcome construction challenges such as large water inflow and reverse-slope drainage in long inclined shafts, thereby achieving water-free operations within the tunnel. The construction through strongly water-rich strata employs the three-bench seven-step excavation method, which utilizes advanced and radial water-blocking technologies to effectively control surrounding rock deformation challenges, thereby providing valuable reference for future tunnel construction in water-rich sections.
Full Text
Research on Construction Technology for Tunnels Crossing Strong Water-Rich Strata in Complex Environments
LUO Yuanyu
China Railway 16th Bureau Group Fourth Engineering Co., Ltd., Beijing 101400, China
Abstract
The Heping Tunnel on the Taixi Railway line traverses a fault fracture zone characterized by highly fractured rock masses at lithological contacts, well-developed intrusive and fault structures, and extremely poor stability of surrounding rock. The presence of a strong water-rich zone creates a high risk of water inrush and mud burst, posing significant challenges to construction safety.
To ensure both excavation progress and worker safety, advanced geological prediction technologies including Tunnel Seismic Prediction (TSP) and ground-penetrating radar were employed to analyze geological conditions ahead of the excavation face, providing critical technical guidance for safe tunnel advancement. Advanced water drainage measures were implemented to address challenges posed by high water inflow volumes and reverse-slope drainage from long inclined shafts, successfully achieving dry working conditions within the tunnel. The three-bench seven-step excavation method, combined with advance water sealing and radial water blocking techniques, effectively controlled surrounding rock deformation. This comprehensive approach offers valuable insights and practical experience for future tunnel construction projects in similar water-rich geological conditions.
Keywords: water-rich strata; construction safety; advanced water drainage; excavation; surrounding rock deformation