At 10:10 on February 27, the No.1 Guozigou Tunnel was successfully linked up after 17 months of construction, marking the final transfixion of the Guozigou Tunnel Group, the largest controlling work of the western section of the Second West-East Gas Pipeline, one month ahead of schedule.

Guozigou is located at Tianshan Mountain, northwest of Huocheng County, Yili, Xinjiang Uygur Autonomous Region. It is an important gateway from China to Middle Asia and Europe from of old, with strategically important terrain that is difficult to access and complicated topography. With snow and ice covering stage of over 200 days a year and extreme low temperature of nearly minus 40 degrees, Guozigou is a major natural barrier for the construction of the Pipeline.

The Guozigou Tunnel Group is composed of seven tunnels, among which the No.1Tunnel is the longest one (3080 m), with the highest altitude (2480 m at the exit), most complicated geological conditions and the greatest construction difficulties. Construction of No.1 Tunnel was started in October 2007. It is the first one to be constructed and the last one to be finished among the seven. A middle line transfixion deviation less than three centimeters at a full length of three kilometers, and an average footage of 7 meters per each actual working day have become new records in China's engineering and pipeline tunnel construction history.