On April 12, the tunnel in the section from Comprehensive Shaft 4 to Comprehensive Shaft 5 of Package 1 of the Shenzhen Metro Line 16 Joint-Construction Utility Tunnel, in which the China Railway 16th Bureau Group participated in construction, was successfully holed through, marking that the entire tunnel of this package has been fully holed through and laying a solid foundation for the project's completion on schedule.
The Shenzhen Metro Line 16 Joint-Construction Utility Tunnel is among the first batch of underground comprehensive utility tunnel projects built in Shenzhen, and is also the largest-diameter comprehensive utility tunnel project undertaken by China Railway Construction Corporation in Shenzhen. The project route has a total length of 9.24 kilometers, with 9 comprehensive shafts and 2 outlet shafts, and all sections are constructed by the shield tunneling method.
Layout Plan of Package 1 of the Shenzhen Metro Line 16 Joint-Construction Utility Tunnel
The Comprehensive Shaft 4-5 section undertaken by the Group's Rail Company is the most difficult section of the project. The route starts from Comprehensive Shaft 4, passes beneath the main structure and ancillary structures of Huanggekeng Station of Metro Line 16, then passes through Outlet Shaft 2, turns east after reaching Longping West Road, and enters Comprehensive Shaft 5. The section has abundant groundwater, and the geology consists of strongly developed limestone karst strata; the borehole cavern-encounter rate along the entire line is as high as 64.58%. Above the tunnel, there are various pipelines on the ground, including gas, communications, water supply, and rainwater pipelines. The horizontal distance from the existing metro line is only 16.37 meters, with high settlement control requirements and great construction difficulty.
Plan View of the Comprehensive Shaft 4-5 Section
Since the shield machine was launched, the project team has repeatedly invited shield tunneling experts to guide construction, repeatedly analyzed and studied the under-crossing schemes and measures, organized emergency drills for water inrush rescue, and effectively reduced the reception risk. It actively coordinated with multiple parties such as the owner and the supervisor, scientifically formulated construction organization plans, reasonably optimized resource allocation, established video monitoring, ground radar scanning, monitoring and measurement, and comprehensive advanced geological prediction systems, established a long-term working mechanism for graded control of construction safety risks and hidden danger investigation and governance, implemented "checklist-based" and "closed-loop" management, adhered to pre-shift education, clarified post-specific safety risk points, implemented safety responsibilities, and strengthened control over the entire construction process.
During construction, in response to the relationship between karst and the tunnel position, the project team carried out targeted karst treatment, achieving "one scheme for each cavern" and strictly controlling the quality of karst treatment. When tunneling in areas with densely developed karst, they combined HSP advanced geological prediction technology, adjusted the tunneling mode in a timely manner, and pioneered the use of the "grout-assisted method" for tunneling, solving the problem of muck gushing and ensuring the smooth and successful passage of the shield machine.
In karst development areas, the connection between karst caves and underground karst fissures may make conventional pressurized chamber opening impossible, increasing the difficulty and risk of opening the chamber to inspect cutters. In response, based on survey data and advanced geological prediction results, the project team adopted the "thick slurry chamber-filling method for chamber opening" measure and successfully opened the chamber 31 times, effectively solving construction difficulties such as water inrush, air leakage, and unstable tunnel face in karst areas, ensuring the safety of existing metro stations and operating lines, and accumulating a complete set of technologies and referable experience for large-diameter shield tunneling in similar strata.
Construction Personnel Celebrating Full Tunnel Holing-Through
It is reported that the project is expected to be handed over by the end of this year. By then, it will help enhance the flexibility of Shenzhen's infrastructure construction and urban planning, improve the safety of underground facilities, and be of great significance to ensuring the city's long-term sustainable development.
评论 （0）