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.