Striving forward in spring, it is the right time to work hard. The Tunnel Company of China Railway 14th Bureau Group coordinated quality improvement and efficiency enhancement, safety production, and technological innovation to build premium projects in all aspects, and with the striving posture of "the start is the decisive battle, the beginning is the sprint," set off a production upsurge of steady progress across projects throughout the country.

Shield tunneling management personnel of the Beijing-Tangshan project guiding workers in construction

At the construction site of the Yunchaojian River Tunnel of the Beijing-Tangshan Intercity Railway of China Railway 14th Bureau Group, the major passage into Beijing, a "steel giant dragon" with a total length of more than 100 meters, a total weight of more than 3,000 tons, and a diameter of 13.3 meters—the "Jingtong" shield tunneling machine—is slowly tunneling underground. The project actively carried out major safety inspections, taught the first safety lesson, and conducted post-holiday safety warning education and training, achieving full coverage of safety education for all project employees and tightening the "safety rope" for resuming work. The Yunchaojian River Tunnel is the last tunnel for the full-line breakthrough of the Beijing-Tangshan Intercity Railway and is currently the largest-diameter high-speed railway shield tunnel in the Beijing area. Its construction is of great significance for implementing the national strategy of coordinated development of the Beijing-Tianjin-Hebei region.

Shield tunneling construction site of the Tianjin-Weifang project

After the Spring Festival, the first-started section project of the Tianjin-Weifang High-Speed Railway of China Railway 14th Bureau Group planned ahead and actively organized hidden danger investigations to fully advance construction production. The Tianjin-Weifang High-Speed Railway is an important component of the "eight vertical and eight horizontal" high-speed railway skeleton and also a common component of the Beijing-Shanghai auxiliary corridor and the coastal corridor. Its construction is needed to support the national development strategy and can optimize and upgrade the comprehensive transportation corridor in the area east of Beijing-Shanghai, further improve the comprehensive transportation system, and play a major role in promoting regional resource sharing, achieving coordinated regional development, and optimizing the layout of the Beijing-Shanghai railway corridor.

Recently, in the hinterland of the North China Plain, accompanied by continuous snowfall in Shijiazhuang, at the construction site of Tiyu North Street Station of Shijiazhuang Metro Line 5 of China Railway 14th Bureau Group, the last truck of concrete was poured into the 324th retaining pile, marking the perfect completion of retaining pile construction at the station and achieving the goal of being the first on the entire line to complete retaining pile construction. During the retaining pile construction process, the project department strictly conducted tensile tests on mechanical connection joints, concrete slump tests, and tests of the three major indicators of mud specific gravity, consistency, and sand content to ensure that all indicators were qualified. It strengthened quality process control in surveying and setting out during retaining pile construction, precise installation of reinforcement cages, concrete pouring, and mold entry temperature, optimized resource allocation, carried out scientific construction, and ensured proper process linkage.

Shield tunneling construction site of Section 6 of Jinan Metro Line 4

Four shield tunneling machines are tunneling simultaneously, and full-face dolomite strata account for 85% of the total mileage, requiring chamber inspection every 10 rings excavated... On the main road of Jingshi Road in Jinan, Shandong Province, the Section 06 project of Jinan Metro Line 4 of China Railway 14th Bureau Group faces arduous construction tasks. It is understood that all four shield tunneling machines have now entered the critical period of breakthrough operations, and shield reception is expected to be completed successively in the first half of this year. The construction team is going all out to safeguard the smooth progress of shield tunneling construction.

In Zhejiang, the "Yong'an No. 1" shield tunneling machine of Ningbo Metro Line 7 of China Railway 14th Bureau Group successfully launched for the second time at the intermediate ventilation shaft on the right line between Minghai Avenue Station and Yufan Road Station, achieving a good start to the new year and officially beginning the journey of the lower half of the right line of the section, laying the foundation for achieving dual-line breakthrough of the section this year. It is reported that this is the first time China Railway 14th Bureau Group has entered the field of rail transit in Ningbo for shield tunneling construction. To ensure smooth shield tunneling construction, the construction team specially configured two new earth pressure balance shield tunneling machines for the section. The shield machines are equipped with spare grouting and drilling holes at the breast plate, with capabilities for advanced drilling and grouting reinforcement, and are also equipped with an automatic shield tail clearance measurement system, an automatic segment layout system, a belt conveyor muck weighing system, and a synchronous grouting slurry weighing system, etc., enabling long-distance continuous tunneling. The overall design can adapt to Ningbo's special strata and respond to engineering risks under various complex working conditions.

At the annual series of meetings, the company's responsible person stated that the company will continue to uphold the red line of safety production, strictly observe the bottom line of project quality, organize production scientifically, and build premium projects that can stand the test of time.