On March 18, 2020, India’s largest diameter TBM was packed at CRCHI’s first industrial park in the Changsha city, central-south of China. It will pass through Shanghai Port to Mumbai for a costal road project.
With an excavation diameter of 12.19 meters, this Slurry TBM is 80 meters long and has 2,300 tons of weight, an installed capacity of 7,280 kW and a gradeability of 5%. It is the largest diameter TBM among all Chinese TBMs exported to India and the largest one ever in India.
Mumbai Coastal Road Project, a key project in Mumbai, is a 29.2-km coastal road connecting Marine drive to Kandivli. CRCHI Slurry TBM will bore its tunnel section of 1,920 meters. The tunnel construction faces complicated geological conditions that require excavation in deep overburden and pass through a compound stratum of basalt, breccia and shale, with the maximum uniaxial compressive strength up to 200 Mpa.
To solve the challenges, CRCHI Slurry TBM is designed with a mixed cutterhead with eight spokes and eight panels, which will enable the machine to bore in the complicated strata for a long distance. To solve the problems which may easily happen during drive, such as mud cakes forming on the cutterhead and slurry discharge blocking, the TBM is fitted with a big-diameter slurry feeding port and several slurry flushing lines to increase the flow rate of slurry. Furthermore, 20-inch big-sized disc cutters are equipped on the TBM to improve the machine’s rock breaking capacity and prolong its lifespan.
In addition, this CRCHI Slurry TBM adopts many innovative systems, such as dual-chamber indirect slurry control system, dual-circuit automatic pressure system, high-torque and retractable main drive as well as high-power slurry circulation system, which will guarantee successful tunnelling.
This is the 5th TBM from CRCHI in India; CRCHI has already delivered 4 slurry TBMs for the Bangalore Metro Rail Project. The company is very serious about the Indian market and is supporting its Indian clients with timely back-up and other services.