With a total length of 6,225 meters, Beijing Underground Diameter Line is located at Beijingxi Railway Station. The line is roughly east-west, including 181.2-meter-wide open excavation section, 871.3-meter undercutting tunnel and 5,175-meter shield tunnel.

Beijing Underground Diameter Line

The project is the first fully electrified tunnel of railway built under prosperous urban area. Under complex geological condition of sandy gravel, CREC adopted a large slurry shield whose diameter reaches 11.97 meters to excavating this tunnel, which is firstly used in China. As the tunnel of longest construction distance using large-span shallow-buried tunneling method, it is also the deepest underground continuous wall in Beijing.