Info from our Prime Sponsor: CRCHI

Info from our Prime Sponsor: CRCHI

07 October 2022


Recently in India, a Ø12.19m TBM created a new hard rock construction record of large diameter TBM by excavating 456m in a single month during the construction of
Mumbai coastal road tunnel. It proves that China's super-large-diameter TBM technology has already in the forefront of the world.

Mumbai coastal road tunnel passed the mixed stratum of basalt, conglomerate and shale, the maximum uni-axial compressive strength is as high as 200 MPa. There are
many challenges during tunnel construction such as large tunnel face, little launching depth, short distance to the coastline, sharp turning curve and high rock strength.

In view of the complex geological condition, CRCHI has designed a mixed cutter head with eight spokes and eight face plates, which facilitates the long distance and
complex rock condition of tunneling. For the hard basalt, the TBM is equipped with a 20-inch large-sized disc cutter, set up with tool holder protection blocks and alloy
wear plates, etc., which improves the rock-breaking capacity and life span of the cutter.

Earlier on January 10, 2022, the TBM crossed the hard rock with complex geological condition, crossed the fault zones several times, passed beneath 100-years-old
houses with no settlement, and completed 380 meters of minor curvature construction. The TBM assisted the first section of Mumbai coastal road tunnel to be
successfully completed, and at the same time set the record of maximum daily progress of 20 meters and maximum monthly progress of 306 meters.

After the breakthrough of the first interval, the TBM was re-assembled and excavated again in another hard rock mixed strata with a accumulated length of over
1000 meters, which created a new record of 456 meters of single-month progress in hard rock. It is a milestone of Mumbai coastal highway construction.
Since the construction of the project, CRCHI service team undergone the outbreak of Covid-19 pandemic, provided one-stop technical services from assembly,
commissioning and initial driving for the customer, 24-hours equipment escortduring excavation constantly.

Ø12.74m EPB shield TBM applied in Chengdu Railway Tunnel

Ø16.07m Slurry TBM applied in Beijing East 6th ring road Tunnel