长江深处的“极限握手”——高水压强渗透软土地层大直径盾构对接纪实

Core Viewpoint - The successful completion of the Jiangyin-Jingjiang Yangtze River Tunnel marks a significant breakthrough in tunnel engineering, overcoming challenges related to high water pressure and soft soil conditions, showcasing China's advanced capabilities in underground engineering [1][9]. Group 1: Project Overview - The Jiangyin-Jingjiang Yangtze River Tunnel spans approximately 6.4 kilometers and is designed to connect the two banks of the Yangtze River [1]. - The project faced a major setback in February 2023 when a shield machine encountered an unexpected halt after advancing 3.2 kilometers, leaving 1.7 kilometers to be completed [2]. Group 2: Innovative Solutions - The construction team proposed an innovative solution to deploy a second shield machine from the opposite bank to meet the first machine, a method that had not been previously considered [2]. - Extensive discussions and validations involving multiple experts and academicians were conducted to ensure the feasibility of the shield machine docking approach [2][3]. Group 3: Technical Challenges - The primary challenge was achieving precise docking of two shield machines in a high-pressure, water-rich geological environment, requiring millimeter-level accuracy [3]. - A comprehensive monitoring system was developed, incorporating cameras and sensors to collect real-time data on the excavation process and surrounding conditions [3]. Group 4: Successful Docking - The docking was successfully achieved with a horizontal error of 0 millimeters and a vertical error of 2 millimeters, surpassing initial design expectations [4]. - The successful docking was a critical milestone, allowing the project to proceed to the next phase of construction [4]. Group 5: Groundwater Control - To manage the groundwater in the soft soil surrounding the docking segment, a non-symmetric freezing method was employed, creating a solid "ice barrier" to ensure safety during subsequent construction [5]. - The freezing process involved drilling over 300 pipes to lower the temperature of the water-rich soil, with strict precision required to avoid any deviations that could compromise the project [5][6]. Group 6: Final Steps - The final phase involved the dismantling and removal of the shield machines, which required careful cutting and manual labor due to space constraints [7][8]. - The entire process of cutting and transporting approximately 2000 tons of material was executed with meticulous attention to maintain the integrity of the frozen soil [8]. Group 7: Project Completion - The tunnel's main structure was completed on November 29, 2025, with no safety incidents reported throughout the construction process [9]. - The project is expected to be fully operational by mid-2026 and serves as a model for future complex underground construction projects [9].