二十年间，从“万里长江第一隧”到“万里长江高铁第一隧” 铁龙过江，见证水下盾构技术跃迁（经济新方位）

Core Points - 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 capabilities in high-precision construction and innovative engineering solutions [3][4][6][12]. 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 the excavation face pressure to withstand significant water and soil pressure [5][6]. Group 3: Construction Techniques - Innovative techniques such as precise tunnel axis control and intelligent shield management were employed, enabling real-time data collection and cloud-based collaborative management [6][8]. - The construction process was conducted entirely underground, minimizing disruption to surface traffic and allowing for the assembly and disassembly of the shield machine within a deep underground chamber [7][8]. Group 4: Industry Development - The development of underwater tunneling technology in China has evolved significantly over the past two decades, transitioning from reliance on imported equipment to achieving self-sufficiency in shield machine manufacturing [12][13]. - China now holds a 60% market share in the global shield machine market and has developed the capability to produce machines with diameters ranging from 2 meters to 16 meters [12][13]. Group 5: Future Prospects - Despite advancements, challenges remain in the field of ultra-large diameter shield machines, particularly in achieving full domestic production of key components [13][14]. - The industry is also focusing on enhancing the integration of intelligent technologies, although there is still a gap compared to global standards for automation [14].