Above the surging tide of Hangzhou Bay, three giant concrete tower columns are piercing the sky at a speed of several meters per day. With the completion of the pouring of the 17th section of the 81st main tower pier constructed by China Railway Bridge Bureau, the heights of the three main towers of the Hangzhou Bay Cross Sea Railway Bridge's middle channel bridge have all exceeded the 100 meter mark. The world's longest and highest standard high-speed railway cross sea bridge under construction is transforming from a blueprint to a reality at an astonishing speed, laying a solid foundation for the integrated development of the Yangtze River Delta.

Breaking the record for cross sea bridge construction

As a controlling project of the Nantong Ningbo high-speed railway, the Hangzhou Bay Cross Sea Railway Bridge has a total length of 29.2 kilometers, a design speed of 350 kilometers per hour, and adopts the standard of double track ballastless track. Among them, the 1.43-kilometer-long Zhonghang Bridge is the world's largest ballastless track three tower cable-stayed bridge, with construction scale and technical difficulty ranking among the world's top. The bridge has three main tower piers, with a middle tower height of 202 meters and a side tower height of 198.5 meters. The entire structure requires the pouring of approximately 40000 cubic meters of high-performance concrete and consumes about 8000 tons of steel reinforcement.

The left limb of the 81st main tower pier poured this time has reached 104.2 meters, and the right limb has reached 110.3 meters; Both limbs of Pier 82 reach 107 meters; Pier 83 has both limbs reaching 109.5 meters. The three main towers are expected to be topped out within the year, marking the fast lane for the construction of the upper structure of the bridge.

Intelligent construction overcomes difficulties

In the face of severe challenges such as strong winds and waves at sea, narrow working spaces, and high salt spray corrosion environments, the construction team has implemented comprehensive and refined control measures. On the material side, high-performance marine concrete is used, and through the whole process of moisture retention and curing technology, the corrosion resistance and crack resistance of the structure are greatly improved, ensuring a hundred year durability. At the construction end, the steel reinforcement processing adopts a workshop prefabrication and on-site installation mode, combined with high-precision measuring equipment and specialized positioning fixtures, to control the spacing error of the steel reinforcement at the millimeter level.

In addition, the project department has established a real-time monitoring system for the construction of the main tower. Stress, settlement, and tilt monitoring points are set up at key parts of the tower columns, and intelligent systems are used to dynamically collect data and adjust construction parameters in real time to offset the impact of wind and waves. In terms of formwork technology, the innovative combination system of chamfered shaped steel formwork and straight hydraulic climbing formwork has been adopted, achieving efficient circulation of segmented pouring. This series of technical combination punches ensures the synchronous construction of the three main tower piers and the synchronous breakthrough of the hundred meter elevation, laying a solid foundation for the subsequent installation of the main beam and inclined cables. Keywords: Cross sea railway bridge, infrastructure construction

From a height of 100 meters, this steel giant dragon is gradually merging. The Hangzhou Bay Cross Sea Railway Bridge is not only a physical transportation hub, but also a concentrated display of China's infrastructure strength. After its completion and opening to traffic in 2027, it will significantly shorten the travel time from Ningbo to Shanghai, extending the urbanization effect of the Yangtze River Delta urban agglomeration from land to sea.Editor/Cheng Liting