On 12 October, 2016, a Φ12.14m EPB TBM finishes FAT in CREG Workshop, Zhengzhou HQ. The machine which is the largest diameter of its kind applied to domestic high speed rail construction is independently developed and manufactured by CREG.

The 135m long EBP TBM is as high as 4-storey building and weighs 2800 tons. The maximum boring speed can reach up to 3.6m per hour. It will be applied to Southwest Ring Project of Taiyuan High speed rail. TBM tunnel of this project extends 4850m from South Fenhe Station to Beiliupu Station with overburden ranges from 8 to 25m. The client China Railway and contractor The Sixth Engineering Bure CREC turned to TBM to keep disturbance to surrounding buildings and underground facilities in this section to the minimum. This double-track one-tube tunnel is designed for passenger and cargo transport and for that reason big tunnel clearance is required. A tailor-made large diameter EPB TBM program is thus proposed by CREG. 

Anticipated problems with a TBM of this diameter include great pressure on tunnel arc, low rotational speed and frequent cutter wear. A 1.8km section of pebbles whose particle size is up to 500mm makes boring even harder. CREG R&D team come up with a series of specific designs. Adjustable cutterhead opening ratio ensures TBM’s adaptability to both soft soil and pebble strata. The cutterhead panel design minimizes disturbance to top excavation face and ground settlement. The ring beam is welded by wear-resistant alloy to protect cutterhead while driving through long-distance pebble strata.

Present at the ceremony are representatives from Taiyuan Railway Administration, China Construction Machinery Association, Commission of Industry and Information Technology of Henan Province and other industry experts. Prior to the ceremony, these experts attend a seminar on the R&D of the large diameter TBM, intelligent TBM and big data in CREG HQ.