Shenzhong Channel will build a two-way eight-lane undersea immersed tube tunnel

Song Shenyou, chief engineer of the Shenzhen-Zhongshan Link Administration Center who participated in the entire process of the project design, holds that the Shenzhen-Zhongshan Link is a world-renowned "tunnel-island-bridge-underwater interchange" cluster project. The 6.8-kilometer extra-long two-way eight-lane steel shell concrete immersed tube tunnel of the project has five major technical difficulties, namely ultra-wide width, variable width, deep burial, large amount of back siltation, and poor formation stability in the sand excavation pit area. It has greater technical challenges and is one of the projects with greater technical difficulty in the world so far.

In fact, there is no precedent for a two-way eight-lane submarine immersed tube tunnel in the world. The innovative structural scheme of steel shell concrete immersed tube, each standard tube section measures 46 10.6 165 meters, is the first of its kind in China and is applied on a large scale internationally, which brings great technical challenges.

Song Shenyou noted that the dimensions of the tube section components of the steel shell concrete immersed tube structure far exceed the experience range of existing foreign engineering cases. At present, China also lacks a complete set of technical standards and specifications for steel shell concrete immersed tube tunnels. In addition, the project has a total of 32 tube sections, each with a steel consumption of about 10,000 tons, and the volume is equivalent to the hull of a medium-sized aircraft carrier. The construction schedule requirement of one tube section per month poses a great challenge to the steel shell manufacturing capacity. Constrained by the water depth conditions of the channel and the dry dock prefabrication yard, the floating transportation distance of the tube section and the horizontal towing distance along the foundation trench are long, which brings high risks to floating transportation and installation.

To address these technical challenges, the administration center adheres to the innovation-driven construction concept, and has carried out a series of scientific and technological researches in terms of structural theory, design methods, technical standards, materials, construction technology, intelligent manufacturing, equipment, detection methods and other aspects, and achieved fruitful results. It not only provides technical support for the construction drawing design and project construction of the immersed tube tunnel, but also fills the technical gap in the construction of steel shell immersed tube tunnels in China.