China News Service, Guangzhou, May 17th (Cai Minjie, Chen Zhengdong, Liu Hailang) The Guangdong-Hong Kong-Macao Greater Bay Area Super Project Shenzhen-Zhongshan Channel offshore box girder erection made a new breakthrough. On the morning of the 17th, it lasted 1 hour and 50 minutes. The non-navigation hole bridge is erected with the highest box girder erection, which is equivalent to a 22-story building.

  The steel box girder erected this time is 86.1 meters long, 20 meters wide, weighs 1,250 tons, and has a hoisting height of 61.136 meters, which is equivalent to a 22-story building.

  The Shenzhong Channel is a cross-sea cluster project integrating "bridges, islands, tunnels, and underwater communication". The total length is about 24 kilometers, of which the bridge project is about 17 kilometers long, including the super-span suspension bridge Lingdingyang with a main span of 1666 meters. Bridge, cable-stayed bridge with a main span of 580 meters, Zhongshan Bridge, non-navigation hole approach bridge and land approach bridge, etc.

The approach bridge of the non-navigable hole bridge adopts steel box girders and concrete girders, with a total of 293 pieces. There are many types of girders, heavy tonnage, and high erection accuracy requirements.

  The transportation and erection of the box girders of the non-navigable hole bridges on the whole line is carried out by the "Tianyi", an integrated carrier-transporting ship independently developed by the China Railway Bridge Bureau.

"Tian No. 1" is the first crane vessel for offshore beam erection construction with a single-hull structure and full electric propulsion in China, with a lifting capacity of 3,600 tons.

The use of "Tian No. 1" has effectively reduced the input of tugboats and transport ships and the time for process conversion and handover, and improved the efficiency and safety of box girder erection.

Shenzhen-Zhongshan Channel completed the erection of the highest box girder at sea. Photo courtesy of China Railway Bridge Bureau

  "This erection is a test of the hoisting ability of 'Tian-1'. The box girder erection has long transportation lines and many crossing channels. The construction of beams, transporting and erecting beams requires a specific tide level, which is difficult and has high safety risks. The hoisting operation site is only 375 meters away from the Lingdingyang Channel, and there are many ships passing through the channel, so the surge has a great impact." said Chen Jianbo, Chief Engineer of the Shenzhong Channel Project of the China Railway Bridge Bureau.

  The S07 contract section of the Shenzhen-Zhongshan Channel Project of the China Railway Bridge Bureau established a research group to improve the coordination mechanism between various processes to ensure that the process and process control are in place, and to achieve safe and precise erection.

  At present, the Shenzhen-Zhongshan Channel has completed the erection of 173 offshore box girders. It is planned to complete the erection of the box girders of the whole line of non-navigation hole bridges in October this year, laying the foundation for the completion and opening of the Shenzhen-Zhongshan Channel as scheduled in 2024.