By rosebell
While the 16m-diameter Jinghua, which is deployed on the Beijing East Sixth Ring Road Reconstruction Project, was the owner of previous record, as the largest diameter shield TBM produced in China,TBM Jianghai, is almost145m long and weighs 5,000 tons.
Being named by integrating the two concepts of crossing the Yangtze River and being adjacent to the sea in the Haitai Yangtze River Tunnel project, Jianghai’s cutterhead is painted with rolling blue waves, symbolising that the shield machine is due to gather strength to carve out the tunnel below river and sea.
Stretching from Haimen District in Nantong in the north and to Taicang City in Suzhou in the south, the Haitai Yangtze River Tunnel is located in the Yangtze River estuary area of Jiangsu Province, whereas the total length of the bi-directional, six-lane highway is 39.07km, with a cross-river tunnel of 11.185km. The bored tunnel section is 9.3km long.
With maximum depth of almost 75m the highest water pressure of 7.5 bars, the tunnel is going to traverse complex geological belts such as silty clay, and silty clay interbedded with silt and fine sand.
Accrding to CRCHI: “There are many uncontrollable unknown areas along the alignment. How to ensure the continuous tunnelling of the entire machine for 9,315m in the complex environment at the bottom of the river while maintaining high-performance load is the main challenge and problem faced by the R&D team.”
Considering that the geological challenges must be overcomed, the TBM is equipped with a soft soil cutterhead with accessible cutterhead and alloy cutters that are large, hard, widely covered, and wear-resistant. In order to effectively avoiding abnormal force caused by overload of the main bearing under special circumstances, facilitating cutter change operations, and assisting the cutterhead to break out, the main drive has a telescopic function that can sense the overall force of the cutterhead. It is equipped with a main drive status monitoring system to continuously monitor the operating status.
The scheduled date for completion of the Haitai Yangtze River Tunnel is 2028.
