By rosebell
China Railway Construction Heavy Industry Corporation Ltd’s (CRCHI) 15.07m-diameter TBM named Pioneer broke through on the eastern tunnel of the Pearl River Basin-Guangzhou Haizhu Bay Tunnel project on July 15, whereas nine days earlier, a high-precision breakthrough was made on the first 3.86m-diameter cross passage.
On February 20 2023, TBM Pioneer with 130m length and 4,300 tons weight, was assembled and commissioned less than three months later, and two months after the launch of the TBM for the western tunnel. The maximum advance of TBM Pioneer during tunneling process, which took a month less than for the western line, was 16m per day and 324m per month.
As the first large-diameter bored tunnel in Guangzhou, the Haizhu Bay Tunnel project is 4.35km long and includes the 2.1km TBM section which passes through the fracture zone of the Pearl River Channel twice, a long section of mudstone and muddy siltstone formations, and beneath buildings and piles.
While the length of six cross passages are 14.8-18.1m, the main tunnel segments are C60 high-strength segments, and the cross passages located at more than 45m deep and at an oblique angle to the main tunnel.
Being manufactured by CRCHI, the cross passage TBM features technologies such as rapid breaking of oblique intersection lining, synchronous construction layout, high-pressure sealing, rapid posture adjustment, as well as high-precision guidance correction, whereas its highest daily progress was two ring segments in less than three hours, and it set a record for cutting into the main line tunnel segments.
With aim of decreasing the driving time from downtown to Guangzhou South Railway Station to 15 minutes, the Haizhu Bay Tunnel project’s total value is almost 11.68 billion yuan (£1.27bn) and the scheduled date for its inauguration is 2025.
