This morning, the Yunchaojian River Tunnel, the last tunnel on the Beijing sub-center section of the Beijing-Tangshan Intercity Railway, completed its shield machine excavation task and was successfully holed through. It is learned that this important project milestone marks that all tunnels on the Beijing-Tangshan Intercity Railway have been holed through, laying a solid foundation for the opening and operation of the entire line.

The Beijing-Tangshan Intercity Railway is an important intercity high-speed railway serving the Bohai Rim and the Beijing-Tianjin-Hebei region. The line starts at the Beijing Municipal Administrative Center Comprehensive Transportation Hub Station and ends at the existing Tangshan Station in Tangshan City, Hebei Province, with 8 stations: Beijing Municipal Administrative Center, Yanjiao, Dachang, Xianghe, Baodi, Yutian South, Tangshan West, and Tangshan. The total length of the line is about 148.7 kilometers, with a designed maximum speed of 350 kilometers per hour.

Among them, the Yanjiao to Tangshan section of the Beijing-Tangshan Intercity Railway, operated by China Railway Beijing Group, was opened to traffic on December 30, 2022, and the second phase project, the Beijing sub-center section, is currently being accelerated. The project is invested in and constructed by the Beijing-Tianjin-Hebei Intercity Railway Investment Co., Ltd.

As an important project under construction in the Beijing sub-center section of the Beijing-Tangshan Intercity Railway, the Yunchaojian River Tunnel is 1.3 kilometers long. On December 28 last year, the domestically produced super-large-diameter slurry balance shield machine "Jingtong Hao" was launched, with an excavation diameter of 13.3 meters.

During construction, the "Jingtong Hao" shield machine passed through high-density medium sand strata. The north side of the excavation line is adjacent to the existing Beijing-Harbin Railway line, with the closest horizontal distance being only 19 meters, posing high construction difficulty and technical requirements.

"A train passes on the Beijing-Harbin Railway line on average every 5 to 15 minutes," said Sun Lijun, project manager of the Beijing-Tangshan Intercity Railway project of China Railway 14th Bureau Group. In response to the difficulties and risks, the project team optimized the design plan, adopted high-precision Beidou satellite positioning technology to conduct safety monitoring of the railway subgrade, and strictly controlled the working radius and stationing of on-site construction equipment to ensure no impact on the catenary of the existing line.

At the same time, all-weather measurement data and a digital intelligent command center were used to guide the shield machine to advance accurately and smoothly, with errors controlled at the millimeter level. The shield machine was tailor-designed to achieve one-time excavation of the entire tunnel without changing cutters, reducing stratum disturbance and ensuring the tunnel was successfully holed through on schedule.

In the future, after the Beijing sub-center section of the Beijing-Tangshan Intercity Railway is completed, passengers will be able to travel directly from Tangshan Station to the Beijing Municipal Administrative Center Station, which is of great significance for serving the convenient travel of residents in the Beijing-Tianjin-Hebei region and enhancing the overall economic competitiveness of the region.