Since the successful convening of the 20th CPC National Congress

China Railway 14th Bureau's key shield tunneling projects

across the country

have driven new progress in project construction with solid achievements,

allowing the spirit of the 20th CPC National Congress

to take root at the tunnel face‍

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"Shenjiang No. 1" shield machine on the Pearl River Estuary Tunnel of the Shenzhen-Jiangmen Railway breaks through 1,000 meters

On November 19, the shield tunneling of the Pearl River Estuary Tunnel on the Shenzhen-Jiangmen Railway achieved a breakthrough: the cumulative tunneling of the "Shenjiang No. 1" shield machine reached 1,000 meters. To ensure smooth tunneling of the shield machine in the full-face gravelly sandstone stratum, the project department, targeting the high quartz content of the stratum, carried out advance overhaul of the shield machine and replaced durable cutters, while also accepting the construction conditions. They conducted briefings on construction issues and safety technical disclosures for the current stratum tunneling, and held emergency drills for water and sand ingress, and toxic and harmful gas overflow during shield construction, focusing on improving all personnel's safe operation skills and emergency response capabilities, laying a solid foundation for the shield machine to safely cross the Pearl River Estuary. Currently, the shield machine is advancing steadily at a rate of 8-10 meters per day, with the main shield machine in good condition and segment assembly proceeding normally.

Longest sea crossing: total tunneling length of shield machines on the Guangzhou-Dongguan-Shenzhen Intercity Railway exceeds 5,000 meters

On November 21, the "Shenwan No. 1" and "Shenwan No. 2" on the Guangzhou-Dongguan-Shenzhen Intercity Railway project had accumulated tunneling of 2,765 meters and 2,297 meters respectively, with the total tunneling length of the two lines exceeding 5,000 meters. To promote high-quality development of project construction and deepen the integration of Party building with construction, the project organized all staff to study and implement the spirit of the 20th CPC National Congress, giving full play to the vanguard and exemplary role of Party members. Currently, construction has entered a critical period. By inviting internal and external shield tunneling experts, combining on-site cutter wear patterns, optimizing the chamber opening step distance, and meticulously deploying the process conversion between atmospheric cutter replacement and shield advancement, the project relies on real-time monitoring systems and on-site management to fully focus on safety, production, and quality control, ensuring the subsequent smooth and continuous construction of the full-face hard rock stratum in the sea section.

"Jiangxin No. 1" shield machine on the Jiangyin-Jingjiang Yangtze River Tunnel breaks through 3,000 meters

Recently, the shield tunneling on the right line of the Jiangyin-Jingjiang Yangtze River Tunnel surpassed the 3,000-meter mark, achieving another important milestone in shield tunnel construction and marking a significant step forward in the overall construction progress of the largest-diameter and deepest-buried river-crossing tunnel under construction in China. To advance the project with high quality and efficiency, the project department firmly established the safety production concept, adopted enclosed and grid-based management, and strengthened personnel access control; actively cooperated with local full-staff nucleic acid testing and strictly implemented various prevention and control measures; ensured that personnel movement information was "accurate to each individual and updated daily," actively building a "epidemic-free construction site" to ensure both epidemic prevention and construction. All construction personnel kept a close eye on the target tasks, conducted in-depth research and summarized the impact of the completed tunneling stratum on construction parameters to guide the formulation of reasonable subsequent shield construction parameters, carried out preventive maintenance of equipment, and ensured material supply during the epidemic, effectively and orderly promoting project construction and ensuring stable and high production on site.

"Maglev No. 1" shield machine on the right line of the Changsha Maglev East Extension to Terminal 3 project breaks through 2,000 meters

As of now, the "Maglev No. 1" shield machine on the right line of the Changsha Maglev East Extension to Terminal 3 project has tunneled over 2,000 meters. As China's first underground maglev line, the Changsha Maglev project faces great construction difficulty and high safety risks. During tunneling, the shield machine must repeatedly pass beneath airport aviation fuel pipelines, beneath the Terminal 2 concourse, beneath the sensitive area of the airport runway glideslope over a long distance, and through mixed soft and hard strata over a long distance. Construction settlement control directly affects aircraft takeoff and landing safety. To ensure smooth tunneling, the Changsha Maglev project department organized carefully and invited industry experts multiple times to hold construction scheme review meetings. By strictly enforcing construction production requirements, strengthening process safety and quality control, increasing the frequency of automated monitoring and precise measurement, and strictly conducting day-and-night settlement monitoring, the safety of surface structures is ensured. Recently, the right line shield tunneling has completed 90% of the total, and all construction work is progressing steadily and rapidly.

First gantry trailer of "Dadao Xianfeng" shield machine for Guangzhou Haizhu Bay Tunnel successfully lifted and lowered into shaft

Recently, the Haizhu Bay Tunnel project, Guangzhou's largest-diameter shield tunnel, reached a key milestone: the first gantry trailer of the "Dadao Xianfeng" shield machine was successfully lifted and lowered into the shaft, marking the countdown to shield tunneling construction. Facing the most complex and severe epidemic situation in Guangzhou in three years, the Haizhu Bay Tunnel project, on the basis of accurately implementing local epidemic prevention policies, actively overcame road control restrictions, dynamically adjusted component transportation plans, and had management personnel on-site for all-round supervision to ensure stable transportation of shield machine components. To ensure smooth transportation of all shield machine components, both water-land combined transport and direct land transport were adopted. For oversized and overweight components, water-land combined transport was used; for components such as cutterhead edge blocks and rear supporting steel structures, direct land transport was used. All were transported to the Nanpu launching section for lifting and lowering into the shaft, with assembly and commissioning expected to be completed by the end of the year before launching.

Right line of Pingdi-Low Carbon City interval on Shenzhen Metro Line 3 Phase 4 successfully holed through

On November 20, as the cutterhead of the 6.45-meter-diameter shield machine slowly rotated, the "Dongjin No. 3" shield machine broke through the final barrier and was successfully received, marking a phased victory for the right line of the Pingxi Station to Low Carbon City Station interval on Shenzhen Metro Line 3 Phase 4. This is also the first shield tunnel on the entire line to be successfully received using the steel sleeve method, providing important reference for the construction of the entire line. Since the shield machine was launched on April 16, 2022, the project has carried out advance grouting reinforcement and other measures, while optimizing the shield machine design. Advanced technologies such as soil chamber visualization, automatic shield tail clearance measurement, automatic muck measurement, and tunnel air conditioning and ventilation cooling were adopted. During tunneling, tunneling parameters were continuously optimized to ensure smooth shield advancement. After 218 days, the machine successfully crossed the karst area and overcame adverse effects on construction progress from severe weather such as typhoons and rainstorms.

Shield receiving shaft of the Jiangxinzhou Sewage Collection System Phase II Project completes final ring beam and support construction

Recently, the shield receiving shaft of the Jiangxinzhou Sewage Collection System Phase II Construction Project (crossing the Jiajiang section) completed the final concrete ring beam and support construction. The south bank shield receiving shaft is located in Nanjing Binjiang Park, with an excavation depth of 25.37 meters. The support system adopted a mode of 4 reinforced concrete supports plus 1 steel support, excavated in 6 layers. The receiving shaft has high environmental protection requirements and complex underground pipelines. To ensure safe excavation of the foundation pit, the project department formulated a special construction plan and invited experts for review and verification. During construction, through strict monitoring of the surrounding environment and precipitation water levels, effective measures were taken promptly to strengthen deformation control of the foundation pit and reduce impact on surrounding buildings. Meanwhile, technical personnel worked alongside, and dedicated safety officers supervised on site, ensuring overall safety of foundation pit excavation and support construction.‍

"Xinchuanyue" shield machine on the Shanghai Airport Link Line breaks through 3,000 meters

Recently, the "Xinchuanyue" shield machine on the Shanghai Airport Link Line project broke through 3,000 meters of tunneling, with tunneling mileage exceeding 500 meters in both September and October, entering a phase of comprehensive acceleration. Currently, the "Xinchuanyue" shield machine is advancing rapidly and steadily at 10-12 rings per day. To ensure construction progress, the project department conducted design liaison with internal and external experts multiple times to optimize the construction organization design; by configuring atmospheric replaceable cutters and installing high-flow flushing pumps at the cutterhead center, effective measures were taken to prevent cutter wear and cutterhead mud cake formation caused by crossing silty sand interbedded with silty clay strata; in addition, to implement intrinsic safety, the project department used BIM 3D visualization technology combined with the large shield cloud smart platform to monitor shield tunneling parameters in real time, ensuring the safety of surrounding buildings and structures during crossing.