At 5 PM on November 18, after 20 consecutive hours of uninterrupted pouring construction, the first large compartment underwater bottom-sealing construction of the north anchorage foundation of the south channel bridge of the Zhangjinggao Yangtze River Bridge was successfully completed. This bottom-sealing construction also marks that the anchorage construction has officially entered a stage of rapid advancement.

Construction site

The Zhangjinggao Yangtze River Bridge is the world's largest-span suspension bridge under construction and also China's pioneering work for bridges spanning 2,000 meters, boasting six "world bests" and six "world firsts." Among them, the north anchorage foundation of the south channel bridge is 118.05 meters long, 75.05 meters wide, with a wall depth of 69.5 meters and a foundation pit excavation depth of 38.5 meters. Once completed, it will be the world's largest-volume diaphragm wall anchorage foundation and will also realize the world's first ultra-large-scale composite diaphragm wall anchorage foundation combining support and structure.

As the "heavy counterweight" that helps a suspension bridge "stand firm," the anchorage serves to anchor the entire main cable and is crucial to the whole construction operation. The north anchorage of the south channel bridge, with an area of about 20 standard basketball courts, is enormous in "size," and the construction scene is quite spectacular. The entire anchorage foundation is formed by connecting 32 small compartments built along the perimeter with 15 large compartments in the middle, creating a pioneering "composite" anchorage structure. The first large compartment sealed on that day is located on one side of the anchorage. On site, 6 giant conduits, 10 cement tanker trucks, and 3 mixing stations operated simultaneously, pouring more than 2,800 cubic meters of C30 underwater concrete into the large compartment, with construction elevations from 35 meters underground to 27 meters underground, and the entire operation took 20 hours.

Construction site

"The north anchorage of the south channel bridge is regarded as the 'no man's land' and the 'ceiling' of anchorage diaphragm wall construction, and is recognized as the 'world's No. 1 anchorage.'" Yang Yuan, on-site technical director of the north anchorage of the south channel bridge in Section A2 of the Zhangjinggao Yangtze River Bridge, introduced that this bottom-sealing construction was difficult to organize and required high safety and quality control. The construction team discussed and refined the bottom-sealing plan multiple times and conducted several rounds of simulated rehearsals, ensuring the speed and quality of the bottom sealing.

"We will adopt a phased pouring method for the 15 large compartments and complete the bottom sealing one by one. The total pouring volume is about 44,500 cubic meters, equivalent to the volume of 23.5 standard swimming pools," Yang Yuan said. The large compartments of the north anchorage of the south channel bridge are expected to complete all bottom sealing before the Lunar New Year, laying the foundation for subsequent construction of the base slab, core filling, and top slab. The entire anchorage foundation project is expected to be completed in 2024, after which it will enter the ground engineering construction stage.

Construction site

As a river-crossing channel project prioritized for construction during the national "14th Five-Year Plan" period, the Zhangjinggao Yangtze River Bridge connects to the G40 Shanghai-Shaanxi Expressway in the north and the Zhangjiagang Port Expressway in the south, crossing the Yangtze River within Zhangjiagang, Jingjiang, and Rugao, and promoting integrated cross-river development. The entire bridge is built to expressway standards, with the river-crossing section having eight lanes in both directions and a design speed of 100 kilometers per hour, and the connecting sections on both sides having six lanes in both directions and a design speed of 120 kilometers per hour. Once completed, it will be of great significance for implementing the national strategies of integrated development of the Yangtze River Delta region and development of the Yangtze River Economic Belt, optimizing the layout of river-crossing channels along the Yangtze River mainline, improving the regional road network layout, promoting integrated cross-river development, and building a high-level Yangtze River city cluster.