Press Release - Xiangya Road river-crossing tunnel in Changsha City - On March 12th 2023, the largest slurry TBM in China’s Hunan Province broke through, which marks the completion of the right line tunnelling of the Xiangya Road river-crossing tunnel in Changsha City. This is the largest diameter shield machine tunnel in Hunan Province that has achieved a twin-tunnel break through. The 15.01m slurry TBM ‘Xingsheng’ is manufactured by China Railway Construction Heavy Industry Corporation Limited (CRCHI) and had been launched back on March 30th ,2021.
As the largest river-crossing tunnel in Hunan Province by far, the Xiangya Road river-crossing tunnel is considered a key infrastructure project for Hunan Province, as well as a major project to increase commerce in Changsha City, which is the provincial capital. The total length of the tunnel is 4180m. The left line TBM tunnel is 1429 meters long, and the right line TBM tunnel is 1425 meters long. It is the first two-way six-lane river-crossing tunnel in Changsha and plans to open the main line to traffic by the end of 2023.
The project mainly crosses through moderately weathered rock and slightly weathered slate. The maximum strength extends to 86.6 MPa. There are multiple fracture zones in this section, of which the maximum depth reaches down to 46.3m. At the same time, the Changsha Metro Line 6 was under construction which brought more challenges and risks to the construction.
As a result of the geological conditions, CRCHI customized the 15.01m ‘Xingsheng’ TBM. The cutters were designed specifically to effectively reduce the impact upon the cutter head during the tunneling in the rock and composite strata under the river. The frequency of the cutters replacement was reduced which improved the excavation efficiency.
Breakthrough of Hengqin Mangzhou Tunnel
On March 9th 2023, the 15.01m super-large diameter slurry TBM ‘Zhenxing’ broke through the left line of Hengqin Mangzhou Tunnel in Zhuhai City, which is 800km away from Changsha. The TBM is also manufactured by CRCHI and was launched on July 15th, 2022.
The Hengqin Mangzhou Tunnel is located in Guangdong-Macao Deep Cooperation Zone. The tunnel is about 3 km long and is planned to be opened to traffic in 2024. The tunnel crosses under the Maliuzhou Waterway, connecting Hengqin Island in the south and Zhuhai City in the north. The whole tunnel crossed through a ultra-soft soil layer, where more than 74.7% of the ultra-fine particles were less than 20 microns, and the maximum depth was 50m. It is currently the only super-large diameter shield machine working in such conditions - a subsea tunnel, softest stratum and the highest content of fine particles in China. For further information on CRCHI please click here and visit https://en.crchi.com//. 12/23.
