China News Service, Zhongshan, January 22 (Cai Minjieyue Road) Guangdong Transportation Group announced on the 22nd that the E7 pipe section of the Shenzhen-Zhongshan Corridor completed the sinking and docking on the same day. The installation of the project's immersed tube tunnel exceeded the kilometer mark. The construction of the west anchorage bottom plate of Lingdingyang Bridge in the passage is completed.
The deep-to-medium passage is about 24 kilometers long and adopts the technical standards of a two-way 8-lane expressway with a design speed of 100 kilometers per hour. It is planned to be completed and opened to traffic in 2024.
The immersed tube tunnel is about 6.8 kilometers long, and the immersed tube section is about 5 kilometers long. It adopts the steel shell concrete composite structure that is first used in China and the first large-scale application in the world. It is composed of 32 pipe sections and a final joint. Wide submarine immersed tube tunnel.
The E7 installed this time is a standard pipe joint, 165 meters long, 46 meters wide, 10.6 meters high, and weighs about 80,000 tons.
The water depth at the immersed location is nearly 34 meters, which is the largest water depth since the construction of the project's immersed tube tunnel.
The E7 pipe joint is the first natural foundation pipe joint of the project, that is, there is no need for foundation treatment after the excavation of the immersed pipe foundation trench. The bottom of the pipe is weathered rock, and there is a risk of a large amount of silt.
"Our immersed pipe installation and construction team observes the back-siltation situation in real time, arranges the dredging work in advance, formulates a thorough plan, and fully implements the countermeasures." said Ning Jinjin, executive deputy chief engineer of the Shenzhen-Zhongshan Passage Project Department of China Communications First Shipping Bureau.
At 3 o'clock on the 21st, the world's first transportation and safety integrated ship "One-way Jinan 1" set sail from Niutou Island, Guishan, with E7 pipe joints, 7 navigation channels, completed about 50 kilometers of navigation channels, and arrived at 14:00 The construction waters near the west artificial island of the Deep-Medium Corridor are ready to carry out related operations.
At 19:30 in the evening, the E7 pipe section began to sink.
At 3 o'clock on the 22nd, after nearly 24 hours of continuous operation, the seventh pipe section (E7) of the Shenzhong Passage immersed tube tunnel successfully completed the sinking and docking.
So far, the total length of the subsea tunnel of the project has reached 1113.5 meters.
The Beidou satellite positioning system is used throughout the installation process. The three-dimensional dynamics of the immersed tube can be calculated in real time through the measurement tower data, which helps the commander accurately grasp the specific position of the immersed tube on the seabed.
On August 28, 2020, during the installation of the E3 pipe section of the immersed tube tunnel of the Shenzhong Passage, for the first time, the Beidou satellite navigation system independently developed by my country was installed as the main positioning pipe section for the project.
The successful installation of the E3 pipe section successfully verified the actual utility of the Beidou satellite navigation system in the cross-sea channel project, and its accuracy and reliability have reached the requirements of the project.
During the sinking of the E7 pipe section, the Beidou satellite positioning system once again played a role.
At 3 o'clock in the morning on the 22nd, the E7 pipe joint was accurately docked with the installed E6 pipe joint, realizing "hand in hand in the deep sea".
Song Shenyou, deputy director and chief engineer of the Shenzhen-Zhongshan Passage Management Center, said that according to the plan, the project will continue to install pipe joints this year. It is expected that the first super-wide and widened pipe joints will be installed in August this year.
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