靠近泉水敏感区，怎样修建地铁？（美丽中国）

Core Viewpoint - The Jinan Metro Line 4, which is the first subway line near the sensitive spring area in Jinan, Shandong Province, has entered trial operation and is expected to open by the end of the year. The line has been designed to avoid sensitive spring areas and minimize the impact on underground water resources, providing a reference for urban rail transit construction in karst terrain cities [2][5][13]. Group 1: Project Overview - Jinan Metro Line 4 has a total length of 40.3 kilometers and is located only 1.4 kilometers from Baotu Spring and 1.5 kilometers from Black Tiger Spring [6]. - The line's construction has successfully navigated the critical water supply channels of the Baotu Spring area, marking a significant step in Jinan's metro development [5]. Group 2: Technical Innovations - A comprehensive underground three-dimensional model has been developed based on over 60 years of hydrological data and recent exploration data, allowing for a clearer understanding of the underground water system [8]. - The project utilizes advanced technologies such as "transient electromagnetic—geological drilling—cross-hole CT" for geological surveys, enhancing the accuracy of underground assessments [8]. Group 3: Environmental Considerations - The design and construction teams have prioritized spring water protection by elevating the station depth and implementing water passage structures to maintain the dynamic balance of underground water [10][11]. - The construction process has included the use of new permeable filling materials and water recycling techniques, achieving a 90% rate of returning extracted groundwater to its original aquifer [12][14]. Group 4: Challenges and Solutions - The construction faced challenges due to the complex geology of the karst area, with nearly 300 caves identified along a 1-kilometer stretch, necessitating advanced geological forecasting and customized equipment for tunneling [13]. - The project has successfully implemented a green construction approach, recycling water and materials during the construction process [14]. Group 5: Monitoring and Results - Throughout the construction, 64 long-term groundwater monitoring points have been established to ensure real-time monitoring of groundwater levels and quality [14]. - As of May 16, the water levels of Baotu Spring and Black Tiger Spring have risen, indicating the successful integration of metro construction with spring water protection [14].