"Ma Wan" Super Large Diameter Mud Water Balance Shield Machine launched

On July 15, the super-large diameter mud-water balance shield machine "Ma Wan", with a diameter of 15.53m, was launched at the 2nd standard of Shenzhen Ma Wan Cross-sea Channel, which was built by Shenzhen Transportation and Public Facilities Construction Center and China Railway Tunnel Bureau.

The total length of the 2 standard shield section is 2063m, and the distance through the high strength rock strata is long. There are more than 1km of uneven soft and hard rock strata and 700m full section hard rock strata on the pushing line, which seriously wear the tool of the shield machine. It is easy to cause the shield machine to float and deviate from the preset track when crossing the complex terrain of the sea bottom. There are problems such as big tool wear and high risk of tool change, and the construction is difficult. The overburden thickness of Mawan undersea tunnel reaches 35m, the maximum water pressure reaches 5bar, and the rock strength reaches 193MPa. In addition, the Mawan Tunnel has a large cross-section and the outer diameter of the segment is 15m, which requires high equipment performance and construction technology.