On April 21, 2021, after 25 hours of continuous operation, the deepest pipe section E9 of the deep-medium channel immersed tube tunnel was completed, and the precise docking was completed at 37 meters. The length of the immersed tube tunnel was 1443.5 meters. The core technology of immersed tube floating transportation installation The comprehensive verification from shallow to deep of equipment, etc. has further consolidated China's leading advantage in the field of immersed tunnel construction in the world.

Zhang Qiansong, Deputy Chief Engineer of Guangdong Provincial Department of Communications, Deng Xiaohua, Chairman of Guangdong Provincial Communications Group, Zheng Shunchao, Director of Hong Kong-Zhuhai-Macao Bridge Administration, Lin Zhijian, Deputy Director, Party Secretary Ya Gang, Chief Engineer Song Shenyou, Leader of First Navigation Bureau Pan Wei, Wu Fengliang, Assistant General Manager Su Faqiang, and representatives of design, supervision, Maritime Safety Administration, National Oceanic Forecasting Center and other relevant units participated in the whole process.

The E9 pipe section installed this time is 165 meters long, 46 meters wide, 10.6 meters high, and weighs about 80,000 tons. The sinking location is the lowest point of the tunnel site. The bottom of the foundation trench is 30 meters below the original mud surface and crosses north-south. The alumite channel crossing at the tunnel site is equivalent to the “silt pit” of the entire tunnel under the influence of ocean currents, and the risk of back siltation is high. Affected by the deep water tank, it is more difficult to control the attitude of the pipe section; the installation period of the immersed pipe coincides with the most active period of the ionosphere during the day, and the risk of signal loss is high.

Difficulty of installation

In order to effectively cope with problems such as the large amount of back siltation on the seabed and avoid the risk of tilting of the leveler due to the structural instability of the bedrock area, the world’s largest and most advanced stone leveler "Yihang Jinping 2" once again adopted the domestically pioneered semi-floating Leveling process. At the same time, the construction team combined the performance of the integrated ship, optimized the cable system design, introduced the Beidou system, and strengthened dynamic monitoring, which provided an effective guarantee for the transportation and installation of the immersed pipe. At 2:45 pm on the 20th, the world’s first immersed, tube-transport-safety integrated vessel "One Sail Jin’an 1" Floating Floating E9 pipe section set sail, and after 7 channel changes, it arrived at the top of the E7 pipe section at 2:30 am on the 21st. Waters. At this time, it is 300 meters away from the installation position of the E9 pipe joint, and the one-piece ship is the first heavy-duty long-distance cross-current navigation. After 15 minutes of DP sailing, it safely arrived at the sinking position of the E9 pipe section. At 8 o'clock in the morning, the E9 tube section began to sink; at 3:50 in the afternoon, the E9 tube section was docked.

The Shenzhen-Zhongshan Passage is located in the core area of the Pearl River Estuary and is the only highway that directly connects the two economic circles of "Shenzhen, Dongguan and Hui" and "Zhuzhongjiang". The project adopts the East Tunnel West Bridge program, and uses an extra-long subsea tunnel of about 7 kilometers to pass through the branch channel of Bao'an Airport and the alumite channel to ensure smooth navigation in the area. The project is expected to be completed and opened to traffic in 2024. Editor/Xing Wentao、Design/Zhangtao