经济新方位｜铁龙过江，见证水下盾构技术跃迁

Core Viewpoint - The successful completion of the Chongqing Caiyuanba Yangtze River Railway Tunnel marks a significant advancement in China's underwater shield tunneling technology, showcasing the country's ability to construct complex infrastructure projects with high precision and safety [2][3][11]. Group 1: Project Overview - The Chongqing Caiyuanba Yangtze River Railway Tunnel is approximately 11.9 kilometers long, connecting the Yuzhong District and the Nan'an District of Chongqing, and it traverses four different environments: mountain, city, water, and river [3]. - The underwater section of the tunnel is 1,282 meters long, with challenging geological conditions including varying mudstone and sandstone, and a minimum cover thickness of only 10 meters [3][4]. Group 2: Technology and Equipment - The project utilized a domestically designed large-diameter slurry balance shield machine named "Yangtze No. 1," which has a diameter of 12.66 meters and weighs approximately 3,500 tons [5]. - The shield machine is equipped with a high-precision gas-liquid pressure balance control system, allowing for precise adjustments to withstand significant water and soil pressure during tunneling [5][6]. Group 3: Construction Techniques - Innovative techniques such as precise tunnel axis control and intelligent shield management were applied, enabling real-time data collection and cloud-based collaborative management [6]. - The construction process was conducted entirely underground, minimizing disruption to surface traffic and urban life, marking it as the first high-speed rail large-diameter shield project in China to complete all operations underground [7]. Group 4: Historical Context and Development - The development of underwater tunneling technology in China has evolved significantly over the past two decades, transitioning from reliance on imported technology to achieving self-sufficiency and leading in the field [12][14]. - The successful construction of the Wuhan Yangtze River Tunnel in 2008 and the Nanjing Yangtze River Tunnel in 2009 marked critical milestones in the advancement of China's underwater shield tunneling capabilities [10][11]. Group 5: Industry Competitiveness - China's shield machine industry has rapidly advanced, achieving a 60% share of the global market and developing machines with diameters ranging from 2 meters to 16 meters [12]. - Despite significant progress, challenges remain in the ultra-large diameter shield machine sector, particularly in the complete localization of key components [14].