中铁大桥局承建世界最长跨海铁路大桥首座主塔封顶

Core Insights - The Hangzhou Bay Cross-Sea Railway Bridge has reached a significant construction milestone with the successful topping of the 8th main tower, which stands at 200 meters high, marking it as the first main tower to be completed among the three navigation bridges and seven main towers along the bridge [1][6]. Group 1: Project Overview - The Hangzhou Bay Cross-Sea Railway Bridge is a key project for the Tongzhou-Ningbo High-Speed Railway, located north of the existing Hangzhou Bay Cross-Sea Highway Bridge, with a total length of 29.2 kilometers, making it the longest cross-sea railway bridge currently under construction in the world [6]. - The bridge consists of three navigation bridges (north, middle, and south) and 26 kilometers of sea and shallow water approach bridges, designed for a double-track ballastless track with a speed of 350 kilometers per hour, classifying it as a super-long high-speed railway bridge cluster project [6]. Group 2: Engineering Details - The North Navigation Bridge is 932.7 meters long with a main span of 450 meters, making it the largest span ballastless track cable-stayed bridge under construction globally [6]. - The main towers (8th and 9th) utilize a curved H-shaped reinforced concrete structure, both standing at 200 meters tall, with high precision construction requirements [6]. Group 3: Construction Challenges - The construction site is located in the Hangzhou Bay, known for its strong tides, swift currents, and frequent typhoons, presenting significant challenges for bridge construction [12]. - To ensure structural safety in the deep sea, the main pier of the North Navigation Bridge employs 52 piles with a diameter of 2.5 meters and a maximum depth of 150 meters, reinforced using a pile bottom grouting technique [12]. - A massive cap with an area of 1950 square meters, equivalent to five standard basketball courts, has been poured above a single main pier, providing stability against the turbulent sea conditions [12]. Group 4: Future Implications - The Hangzhou Bay Cross-Sea Railway Bridge is expected to be operational by 2027, forming an important part of China's "Eight Vertical and Eight Horizontal" high-speed rail network along the coast [12]. - Once completed, the project will connect with multiple railways, significantly enhancing the regional transportation network and facilitating the integration of the Yangtze River Delta region for high-quality development [12].