According to the Ningbo Maritime Safety Administration, at 11 a.m. on April 14, as the drilling vessel "Zhepu Gong 25" slowly pulled the last casing out of the borehole, the geological exploration work for the Hangzhou Bay Cross-Sea Bridge of the newly built Nantong-Suzhou-Jiaxing-Ningbo Railway was successfully completed.


　　The Hangzhou Bay Bridge of the newly built Nantong-Suzhou-Jiaxing-Ningbo Railway is an important part of the national "Eight Vertical and Eight Horizontal" high-speed railway coastal corridor. It is located about 7 km upstream of the existing Hangzhou Bay Highway Bridge, with a sea section length of about 29.2 km. The bridge includes three navigation channel bridges: north, middle, and south. Once completed, it will become the world's longest and highest-standard cross-sea high-speed railway bridge. This geological exploration is to determine the specific location of the bridge route and to ascertain in detail the engineering and hydrogeological conditions of the bridge site area. Since the project started on October 18 last year, 9 drilling platforms, 17 construction vessels, and more than 420 workers have been involved, completing a total of 401 offshore exploration points, one and a half months ahead of the original schedule.


　　The natural environment of the Hangzhou Bay sea area is harsh, with a maximum tidal range of nearly 9 meters, a maximum flow velocity of up to 5 meters per second, and frequent "microclimates." The upper mud layer of the seabed is 20 to 40 meters thick, and the operation also involves nearly 3 kilometers of offshore tidal flat sections. The interface of the silty sand layer often contains honeycomb-like shallow gas, which poses great challenges to offshore exploration operations. To ensure construction safety, the Navigation Management Office of the Ningbo Maritime Safety Administration established a special task force to guide the preparation of a navigation safety assurance plan. In response to the safety risks of tidal flat construction, they guided the project department to achieve the first "sitting on the beach" construction method within Zhejiang Province.


　　To enable the project to start as early as possible, under the guidance of the Zhejiang Maritime Safety Administration, the maritime departments of Ningbo and Jiaxing implemented a five-dimensional model of "nearby application, joint review, single licensing, territorial supervision, and mutual recognition of results" to improve regulatory and service efficiency. During the Spring Festival, under the unified leadership of the construction units (Suzhou Command, Ningbo and Jiaxing Railway Command), the construction contractors (China Railway Bridge Institute, China Railway Design) actively seized the construction window period, adhered to 24-hour operations, ensured the project was completed with quality and quantity, and laid a solid foundation for subsequent preliminary design and construction.