Press release - On December 12th - after 14 months of boring - Jinxiu, the China’s largest EPB TBM, developed by CRCHI marked its first major breakthrough in the Jinxiu Tunnel, a key part of the 259 km-long Chengdu-Zigong High-speed Railway project, with design speed of 350 km per hour.

The TBM Jinxiu is 12.79m in diameter and has a total weight of 3,000 t. The TBM is 135m long and has a installed power of 7500kW. The shield is painted with a giant panda holding bamboo.     

Located in Jinjiang District, Chengdu, the Jinxiu Tunnel starts at the Chengdu East Railway Station and the TBM is 1 km south. The tunnel comes above ground after the South Third Ring Road, and has a total length of 3,655 m, 2,620 m of which driven by TBM.      

The tunnel depth is 8 m to 60 m underground. The project passes under built up areas such as Chengdu's southeast central ring road, which has high-rise buildings, many municipal tracks, and complex pipelines: this made construction difficult and extremely high risk.     

In order to cope with the above-mentioned complex geology and surrounding environment, the R&D team of CRCHI carried out a tailored design of the TBM Jinxiu and solved a series of construction problems. For example, through the optimization of the tool design, only 2 cutters were changed during the total 1937-m advancement in the composite strata with strong and weakly weathered mudstone, and the TBM passed - without any risks - under the existing Chengdu East Ring Right Line and Chengdu-Guiyang High-speed Railway having all ballasted tracks.    Click here for the tunnelbuilder archive and visit https://www.crchi.com/ 51/22.