张靖皋长江大桥南航道桥双主塔封顶

Core Points - The Zhang Jinggao Yangtze River Bridge has completed the main tower construction for both the south and north navigation bridges, marking a transition from substructure to superstructure work [1] - The south navigation bridge features a main span of 2300 meters and is currently the tallest suspension bridge in the world, with both main towers standing at 350 meters [3] - The steel usage for a single main tower is approximately 34,000 tons, equivalent to the steel used in 4.6 Eiffel Towers [3] - The main towers utilize an innovative "steel box-steel pipe concrete constraint composite system," reducing the self-weight of the towers by about 50% and enhancing wind and seismic resistance by 30% [3] - The construction employs a modular assembly approach, with tower columns made of 30 prefabricated segments [3] - The installation of the upper crossbeam involved three segments, with the heaviest segment weighing 262 tons, using a world-first 10,000-ton level tower crane [4] - Advanced 3D digital technology was utilized for the entire process simulation, achieving high precision in the welding seams [4] - Key construction points for both navigation bridges are progressing simultaneously, laying a solid foundation for the subsequent cable system installation [6]