The cross-sea passage connecting Shenzhen and Zhongshan
On June 30, 2024, a world-renowned super project in the Guangdong-Hongkong-Macao Greater Bay Area, the Shenzhen-Zhongshan Passage opened to traffic upon its completion.
The construction of the 24-kilometer cross-sea passage was started on February 2017. The passage is the world's first cross-sea cluster project integrating "bridges, artificial islands, tunnel and underwater highway interchanges" and featuring with major structures such as an extra-wide and extra-long steel-shell concrete immersed tube tunnel, super long span suspension bridges and artificial islands in the sea, and the underwater highway interchanges for the Shenzhen Airport. As a key "cross" in the framework of the A-shaped transportation network around the Pearl River Estuary, the passage spans the Lingdingyang Bay at the Pearl River Estuary, reducing travel time between Shenzhen and Zhongshan from about two hours to under 30 minutes, which is of great significance in propelling the economic and social development of the Greater Bay Area.
The passage is located in the core area of the Pearl River Delta, about 30km from the Humen Bridge in the north and 38km from Hong Kong-Zhuhai-Macao Link in the south. It is surrounded by important ports such as the Guangzhou Port and Shenzhen Port, the largest main port hub in South China. The bridge zone of the passage is traversed by important waterways such as the Guangzhou Port sea-going channel. It is one of the navigable waters with the most dense coastal routes and ships in China. Featured by the dynamic geomorphologic pattern of "three shoals and two troughs" of the Lingdingyang Bay, the passage is in an extremely complicated environment of water-sediment movement. The construction of the bridges in the passage faces a series of challenges, such as bridge site selection, arrangement of major navigable zone, artificial island plane optimization, and reasonable span of bridge aperture.
Physical model test
Nanjing Hydraulic Research Institute (NHRI) has given full play to its technical advantages and undertaken water-related special researches during the whole process of the construction of the Shenzhen-Zhongshan Passage, including the stages of planning, design and construction, over the past 10 years. At the stage of project feasibility study, NHRI adopted comprehensive research measures, including field observation, water-sediment mathematical model calculation and physical model test, to select and optimize bridge type and the layout of artificial islands and the tunnel, and demonstrated the good water distribution of the kite-typed island and the stability of the submerged tube base groove, providing an important scientific basis for determining the overall scheme of "west bridges, east tunnel and kite-typed artificial island" for the Shenzhen-Zhongshan Passage. At the stage of project preliminary design, NHRI completed the analysis of the evolution of water-sediment environment in the project sea area and the special study of back-siltation in base groove, and solved the problem of high sedimentation in base groove, providing important technical support for the safe floating and smooth sinking of submerged tubes. At the stage of project construction, NHRI conducted more than 10,000 laboratory tests, more than 1,000 sets of single compartment model tests and several full scale model tests to verify the complex structure of steel-shell concrete sandwich adopted for the first time in China, proposed a high-precision nondestructive testing method for calculating the disengaging of concrete inside steel shell based on the attenuation degree of neutron source energy, and independently developed the first set of millimeter-level nondestructive testing equipment of concrete disengaging, completing the detection of more than 100,000 measured points in all tube segments of the Shenzhen-Zhongshan Passage in a safe, efficient and high-quality manner.
Detection of concrete disengaging by NHRI engineer under the scorching sun
Along with the official opening of the Shenzhen-Zhongshan Passage, NHRI will, as always, strive to solve the key technical problems in the construction of comprehensive transportation system in the Greater Bay Area, and contribute wisdom to building the Greater Bay Area into a strategic fulcrum of the new development pattern, a demonstration site for high-quality development, and a leading place for Chinese-style modernization.
