On June 29, 2025, the first prefabricated pier section with a height of 7 meters and a weight of 500 tons at the construction site of the Hangzhou Bay Cross-sea Railway Bridge jointly designed by the China Railway Bridge Institute and China Railway Bridge Bureau jointly designed by the Shanghai-Hangzhou Passenger Dedicated Company and China Railway Bridge Bureau was accurately erected on Pier 108 under the hoisting of the "Yingshang 1" crane ship. This is the world's first time to complete the construction of large-diameter ultra-long pile foundation prefabricated piers under the complex hydrological conditions of strong tide bays, which not only marks a major breakthrough in the construction technology of China's high-speed rail cross-sea bridges, but also accumulates valuable experience for similar projects in the future.

At 3:30 p.m., a prefabricated pier with a height of 7 meters and a weight of 500 tons was steadily lifted by a crane ship on the sea about 8 kilometers from the shore. After more than two hours, the pier was slowly and accurately erected above pier 108 of the Hangzhou Bay Cross-sea Railway Bridge.

Ingenuity: Strict control of quality and casting of high-quality products

Hangzhou Bay cross-sea railway bridge is a new control project of Nantong to Ningbo high-speed railway, including the north, middle and south three waterway bridges and across the embankment, the sea, the shallow area approach bridge, a total length of 29.2 kilometers, using a speed of 350 kilometers per hour double-line ballastless track design, is currently the world's longest length of high-speed railway bridge, the highest construction standards of high-speed railway bridge.

After completion, it will set a number of world records, which is a milestone in the field of railway bridge construction in the world. The approach bridge in the sea adopts the prefabricated pier design, a total of 91 piers, 180 piers, the erection is the 108 pier top section, the section is 9.1 meters long, 4.1 meters wide, 7.0 meters high, weighs 500t, from Zhoushan Jintang pier yard ship to the site, using 1600 tons of floating crane erection, need to go through lifting, anchoring, initial positioning, fine positioning, gluing, pier locking and other processes.

In the face of high standards and strict requirements, the project personnel have made careful planning and strict control of each link to ensure the quality and transportation safety of the pier body segments. The pier adopts the "self-locking prestressed adhesive joint" connection method applied for the first time in the high-speed railway cross-sea bridge, and belongs to the cast-in-situ-prefabricated combined pier section. This innovative connection method not only improves the overall stability and durability of the pier, but also brings great convenience for subsequent construction and maintenance.

Strategic journey: Fearless challenge and brave forward

As a control project of the new Nantong-Ningbo high-speed railway, the Hangzhou Bay Cross-sea Railway Bridge covers three waterway bridges in the north, middle and south, as well as approach bridges across the embankment, the sea and the shoal area, connecting the north-south traffic.When hoisting, the sea breeze and waves in the strong tide bay made it difficult for the "Yingshang 1" crane ship to operate.

Tan Cong, information commissioner of the Hangzhou Bay cross-sea railway bridge project of China Railway Bridge Bureau, said: "After scanning the segments of the prefabricated pier body and the cast-in-place pier body on the spot, the three-dimensional model is processed by the algorithm and pre-assembled on the digital platform to ensure the construction progress of the site and the accuracy of the pre-assembly." ”

In the early stage of construction, the project team carried out tests such as gluing process, prestressed installation, hoisting test assembly, etc., to provide test data for the erection of prefabricated pier body segments and verify the feasibility of the construction plan; At the same time, through desktop deduction and on-site anchoring drills, the anchorage position of the floating crane and the transport ship is accurately located to ensure the safety and accuracy of the hoisting operation. The project team used digital twin pre-assembly technology to generate digital models of prefabricated pier segments and cast-in-place sections through 3D laser scanning, and strictly controlled the matching surface error at the millimeter level with the help of virtual assembly technology.

This construction is the first time in the world to successfully complete the construction of large-diameter ultra-long pile foundation prefabricated piers under the complex hydrological conditions of strong tide bays. It marks a new leap forward in China's high-speed rail cross-sea bridge construction technology.

High-speed linkage: the Yangtze River Delta adds another "golden channel"

Nantong to Ningbo high-speed railway is an important part of China's "eight vertical and eight horizontal" high-speed rail network coastal channel, from Yancheng to Nantong high-speed rail Nantong West Station, south through Suzhou City, Jiangsu Province, Jiaxing City, Ningbo City, Zhejiang Province, the introduction of Ningbo hub Ningbo Station, the new line is 301 kilometers long, the design speed is 350 kilometers per hour, the whole line has 10 stations, and the construction period is 5 years. After the completion of the Nantong-Ningbo high-speed railway, it will be connected to many lines such as the Yancheng-Nantong high-speed railway, the Shanghai-Nanjing high-speed railway along the Yangtze River, the Shanghai-Kunming high-speed railway, and the Ningbo-Taizhou-Wenzhou railway, which is of great significance for improving the road network structure layout in the Yangtze River Delta region, facilitating the travel of the people along the line, and promoting the integrated and high-quality development of the Yangtze River Delta.(This article is from the official website of Seetao www.seetao.com. Reprinting without permission is strictly prohibited. Please indicate Seetao.com + original link when reprinting) Seetao.com Strategy Column Editor/Sun Fengjuan