Summary:TBM

After the first day of resumption of construction, China railway construction heavy industry group independently developed shield machine and exported it to Turkey, on March 18, in Changsha first industrial park of railway construction heavy industry group, the shield body of a super large diameter shield machine with a diameter of 12.19 meters was disassembled and packed into 8 pieces, and the cutterhead was divided into 5 pieces, which were successively loaded and sent out, transported to Mumbai, India by sea through Shanghai port, and participated in the construction of Mumbai coastal highway tunnel.

The shield machine is 80 meters long, 2300 tons in total weight, 7280 kilowatts in installed power, with 350 meters horizontal turning capacity and 50 ‰ climbing capacity. It is the largest diameter shield machine exported to India by China so far, and it has become the largest diameter shield machine in India, breaking the monopoly of western developed countries in the overseas large diameter shield machine market.

It is understood that the coastal road of Mumbai, India, is constructed along the west coast of Mumbai in the Arabian Sea, with a total length of 30.7km, which is an important road project in India. The tunnel is about 1920 meters long, with complex geological conditions. It is composed of basalt, breccia and shale composite stratum. The maximum uniaxial compressive strength is as high as 200 MPa, and the tunnel is buried deep.

According to the local complex geological characteristics, the railway construction heavy industry design team has customized a composite cutter head with eight spokes and eight panels, which provides a strong guarantee for the excavation of long-distance and complex strata. In order to deal with the problems such as mud cake on the cutter head and slurry discharge port blocking in the process of shield tunneling, a large slag inlet is set in the center of the cutter head of shield machine, and multiple slurry flushing ports are equipped to improve the fluidity of slag. The shield machine is also specially equipped with a 20 inch large-scale hob, which effectively improves the rock breaking ability and service life of the cutter head.

Not long ago, CRCC has shipped four shield machines to Bangalore, India, for the construction of local metro tunnels. It is reported that Bangalore metro tunnel project is faced with the problems of high rock strength, a large number of boulders and uneven soft and hard strata. Through the targeted design of shield machine, CRCC has given a "China plan" for shield machine operation under extreme working conditions, which effectively solves the construction problems of Bangalore Metro tunnel construction, and also marks the beginning of batch of domestic brand shield machines For the South Asian Metro market.