In the scorching summer, undaunted by the "roasting" test

Frontline builders in the blazing heat of midsummer

With burning passion

Firm in practical action, tackling difficulties head-on

Striving to advance key project construction

The construction "progress bar" keeps refreshing

Tianxiang Avenue Tunnel

"Hero" shield machine drives over 1,000 meters

On July 5, the "Hero" shield machine excavating the Tianxiang Avenue Tunnel of the Nanchang-Jiujiang High-Speed Railway surpassed the 1,000-meter mark, with the shield-driven section 22.7% complete, marking a phased victory in the construction of Jiangxi Province's first large-diameter shield tunnel.

During construction, the shield machine had to pass through 820 meters of upper fine round gravel soil, in which the fully weathered and strongly weathered strata contain clay minerals as high as 94%, very likely to cause mud cake formation on the cutterhead. In response, relying on rich shield construction experience and technical accumulation, the project team upgraded its own pipelines and added scouring pipelines to the central panel of the cutterhead, improving the mud cake situation and greatly increasing the excavation speed.

In addition, the project department established a safety hazard investigation and management system, assigning dedicated personnel to conduct 24-hour video capture of all on-site areas through the smart engineering management command center, reporting problems found to a WeChat hazard group, and notifying and assessing various hazards and their rectification.

Jintang Subsea Tunnel

"Yongzhou" shield machine drives past 100 rings

On July 5, the "Yongzhou" shield machine excavating 58 meters underground broke through the 100-ring mark, reaching an excavation mileage of 200 meters, marking phased progress on the world's longest subsea high-speed railway tunnel.

According to reports, during excavation the "Yongzhou" shield machine encountered full-face hard rock strata right from the start, with extremely high rock strength, posing a considerable challenge to the wear resistance of the cutters and cutterhead. At the same time, the shield machine also had to pass beneath crude oil pipelines and refined oil pipelines in a single run, imposing extremely high requirements on surface settlement control.

To this end, the project team relied on the shield machine's cutterhead visualization system and hob wear intelligent monitoring system to conduct intelligent detection and analysis of cutter and cutterhead wear, providing a decision-making basis for efficient rock breaking. Meanwhile, combining years of large shield construction experience, the project team adjusted the shield machine's excavation attitude in a timely manner, carefully controlled excavation parameters, and adjusted and optimized the mud ratio to ensure the shield machine passed through surface risk sources smoothly, quickly, and in a single run.

The Ningbo-Zhoushan Railway starts from Ningbo East Station in the west and ends at Baiquan Town in Dinghai District in the east, with a total length of about 77 kilometers and a design speed of 250 kilometers per hour. Once completed and open to traffic, it will end the history of Zhoushan having no railway access.

Wuxi Yingyue~Wentai Project

"Fenjin" shield machine successfully launches

On July 5, as the cutterhead of the "Fenjin" shield machine slowly rotated, the shield-driven section of the Wuxi Yingyue~Wentai 220 kV line project began excavation, marking the project's official transition into the excavation construction stage.

The project adopted split launching of the shield, with simultaneous excavation and assembly and face pressure maintenance, which are difficult and high-risk. After launching, the shield machine immediately passes beneath the Beijing-Shanghai Expressway, a national transportation artery with heavy traffic, imposing extremely strict requirements on the shield machine's configuration and construction capability as well as surface heave and settlement along the route.

In response to construction difficulties, the project department held multiple special discussions to determine feasible plans, while coordinating surface and underground operations, promptly adjusting various connecting pipelines and electrical equipment controls to ensure normal underground excavation, achieve stable excavation face pressure, ensure a single crossing, and realize high-quality project construction.