According to Changchun Rail Transit Group, at 22:58 on December 13, the last unconnected section of Changchun Metro Line 2 Phase I—the mined tunnel section from Jiefang Bridge to Jianshe Street—safely crossed under the Beijing-Harbin Railway, marking the full connection of the entire line. A total of 3 million cubic meters of earthwork has been excavated.

It is understood that Phase I of Changchun Metro Line 2 starts from Xihu Station in the west, runs along Jingyang Avenue, Jiefang Avenue, and Jilin Avenue to the terminus Dongfang Square. The line has a total length of 22.335 km, entirely underground, with 19 stations. The project started construction of the test section (Yuanjiadian Station) in October 2012 and fully commenced construction in April 2014. Among the 19 stations, 15 are constructed by open-cut method, including 5 prefabricated assembled stations; 3 stations by mined method; and 1 station by covered excavation method. Of the 18 tunnel sections, 13 are constructed by shield method and 5 by mined method. Up to now, the main structure of the civil engineering works is basically completed, and ancillary structures such as station entrances/exits and ventilation shafts are under construction.

It is also learned that subsequent works of Phase I, including track laying and electromechanical equipment installation, have been fully launched. Up to now, a total of 47.5 km of track has been laid, with 40.5 km completed, accounting for about 85.2% of the total; the installation of electromechanical equipment, signaling, and other station electromechanical equipment has completed 30% of the total, including power supply, communication, signal equipment installation, and cable laying.

To achieve the goal of opening to traffic next year, the Changchun Metro Line 2 project has entered the winter construction phase. While overcoming difficulties such as low temperatures, the winter construction plan reviewed by experts is strictly implemented, and subsequent works such as installation and commissioning of electromechanical equipment systems and trial operation of metro vehicles are comprehensively advanced under the premise of ensuring safety.

Application of Prefabricated Construction Method

Phase I of Metro Line 2 includes a total of 5 prefabricated stations: Xihu Station, Yuanjiadian Station, Xixing Station, Xihuan Road Station, and Jianshe Street Station. This is the first time in China that the prefabricated construction method has been applied to metro engineering. Currently, except for Xihu Station, which is temporarily suspended due to land acquisition and demolition, the prefabricated section construction of the other 4 stations has been successfully completed.

Prefabricated stations, through precast components and on-site assembly, greatly shorten the construction period and are particularly suitable for regions like Northeast China that are significantly affected by temperature. The success of the prefabricated stations on Changchun Metro Line 2 provides valuable experience for the practice and promotion of this method.

Shield Tunnel Crossing Under Yitong River

The tunnel section from Nanguan Station to Yanchang Station on Metro Line 2 is the first underground project in Changchun to use a shield tunnel to cross under the Yitong River. Through meticulous planning and deployment in the early stage, the section has achieved double-line connection, and the track laying work has also been successfully completed.