Workers operate at the Yunchaojian River Tunnel of the Beijing-Tangshan Intercity Railway. [Photo provided to chinadaily.com.cn]
As the integration of the Beijing-Tianjin-Hebei continues its advancement, the Beijing-Tangshan Intercity Railway is accelerating its tunneling 30 meters underground in the Tongzhou district of Beijing.
The Beijing-Tangshan Intercity Railway is a fast transportation corridor between Beijing and Tangshan. The section from Tangshan to Yanjiao in Hebei was opened and put into operation on Dec 30, 2022. Among the remaining construction projects, the Yunchaojian River Tunnel is the most challenging. This is the largest-diameter high-speed rail shield tunnel in Beijing so far, with a diameter almost twice that of metro projects. It is also the "final kilometer" project for the full completion of this major corridor into Beijing.
The project, not far north from the starting shaft is the busy Beijing-Harbin Railway, with a train passing by every few minutes. "This project runs parallel to the entire Beijing-Harbin Railway, with the closest distance of only 11.7 meters. Ensuring operational safety is extremely important and cannot tolerate any mistakes," said Sun Lijun, from China Railway 14th Bureau Group Corporation Limited, who is in charge of the Beijing-Tangshan Intercity Railway project. "During the shield tunneling process, the settlement of the Beijing-Harbin Railway was controlled within 1 millimeter."
Considering the geological and environmental characteristics of the tunnel construction for the Beijing-Tangshan Intercity Railway, the shield machine design team customized the domestically produced super-large diameter "Jingtong" shield machine for the project. The machine has a serial number "1388", meaning it is the 1,388th shield machine manufactured by China Railway Construction Corporation. It weighs about 3,200 tons, with a cutter head of 13.3 meters in diameter, roughly equivalent to the height of three and a half floors of a building.
The Yunchaojian River Tunnel of the Beijing-Tangshan Intercity Railway is under construction. [Photo provided to chinadaily.com.cn]
The "Jingtong" shield machine has a total length of about 138 meters, resembling a small train with four different sets of functional flatcars connected in sequence. At the forefront is the massive circular cutter head, which, driven by 16 motors, cuts through soil and rocks, extending the tunnel forward. The subsequent flatcars are responsible for assembling the tunnel segments into place.
Additionally, the cutter head of the shield machine is painted with the image of "Tu'er Ye" (the rabbit god), a symbol of Beijing culture that signifies good fortune and safety. This represents another successful collaboration between traditional culture and major national infrastructure projects.
The "Jingtong" shield machine successfully crossed the 150-meter span of the Yunchaojian River at this location, with only 12 meters between the tunnel crown and the riverbed when the shield machine was working.
According to the staff, the 1,285-meter tunneling of the Yunchaojian River Tunnel will be completed in June this year, and connect with the terminal station in the sub-center, achieving a full-line breakthrough of the Beijing-Tangshan Intercity Railway.
