October 31 witnessed two CREG EPB TBMs completing tunneling section from Xuanrendun Station to Dadiwobao Station to International Airport, Lot 16 of Urumqi Metro Line 1, one year earlier than the previously planned breakthrough date.
 

Lot 16 is the first of numerous planned lots that has adopted TBMs for ongoing Metro building by Urumqi Municipal Government (UMG) to meet increased demand for traffic in the capital city. The two 6.47m EPB TBMs CREC 205 and CREC 206 (also known as Yaxin No.1 and Yaxin No.2) have bored through dense cobble sand and crossed beneath sandstone stock yard back-filled area and Urumqi-Junggar Basin Rail as well as some other ground buildings on their ways. Geological conditions along the back-filled area consist of pebbles as large as 65cm in diameter. Along the alignment are 3 piers with the nearest one 4.5m away from the TBM.

Given the worsening traffic jam in Urumqi, UMG decided to move forward the trial operation of Metro Line 1 by one year earlier in January 2016, which put much pressure on the planned TBM construction program. 

In June, 2016, the two CREG TBMs completed a 2652m-long drive from Xuanrendun Station to Dadiwobao Station in advance. Following a short break for maintenance, the two machines were launched again in July, 2016 for the next drive to International Airport. After three months of smooth advance, CREG TBMs accomplished breakthrough one year ahead of time and registered a record of nearly 500m in waterless gravel stone while maintaining settlement within 5mm. 

The close cooperation between Xinjiang Communications Construction Group (XCCG), the contractor and CREG in design, technical solutions and execution has been key to achieve this.

According to Mr. Wang Zhihua, General Manager of XCCG, CREG has offered excellent technical supervision and trained a large number of local TBM operators. This shall increase our competence in the future TBM construction contracts and lay a foundation for potential TBM application in subsequent lots of Urumqi Metro Line.

The impressive performance of the two CREG EPB TBMs makes the drive from Xuanrendun Station to International Airport a reference construction site visited by plenty of people every day.