宁芜铁路扩能改造工程南京南隧道盾构段贯通

Core Viewpoint - The successful breakthrough of the "Ningwu" earth pressure balance shield machine marks significant progress in the Nanjing South Tunnel of the Ningwu Railway capacity expansion project, which aims to enhance safety and reduce urban disruption caused by the railway [1][3]. Group 1: Project Overview - The Ningwu Railway capacity expansion project includes a realignment of the Nanjing urban section, which will eliminate safety risks associated with level crossings and address urban issues such as noise, pollution, and traffic congestion [3]. - The Nanjing South Tunnel, a key component of the project, is 14.442 kilometers long with a design speed of 120 km/h, traversing through multiple districts in Nanjing [3][9]. - The shield section of the tunnel spans approximately 2.4 kilometers and involves complex geological conditions, including various soil types and proximity to existing infrastructure [3][5]. Group 2: Construction Challenges and Solutions - The construction faced high safety risks due to dense surface structures and limited working space, leading to the adoption of shield tunneling as the primary method [5]. - The project team developed a customized "Ningwu" shield machine, which is 132 meters long and weighs 1375 tons, featuring advanced technologies for safety and efficiency [5][7]. - Techniques such as "micro-disturbance excavation" and "precise guidance" were employed to ensure safe tunneling through critical risk areas, including the crossing of major rivers [7]. Group 3: Future Implications - Upon completion, the Ningwu Railway expansion will enhance the freight capacity of the eastern section of the Yangtze River Economic Belt and improve regional railway network layout [9]. - The project aligns with the principles of "ecological priority and green development," facilitating industrial upgrades and optimizing urban spatial layouts along the railway [9].