Core Viewpoint - The mainline elevated road project of National Highway 312 from Ningzhen to Qixianghe is set to open on December 31, 2025, significantly improving connectivity between Nanjing and Zhenjiang [1][2]. Group 1: Project Overview - The mainline elevated road spans approximately 2 kilometers, starting from the Ningzhen junction and connecting to the existing sections of National Highway 312 and 346, designed for a speed of 80 km/h [2][3]. - Upon completion, travel time from Zhenjiang city center to Nanjing Xianlin area will be reduced from 1.5 hours to about 40 minutes, enhancing traffic capacity and safety [2][16]. Group 2: Construction Techniques - The project features a high prefabrication rate of 90%, utilizing a modular construction approach where core components are pre-manufactured in factories and assembled on-site, improving construction efficiency by over 30% [5][7]. - A total of 464 box beams, 98 cover beams, and 148 pier columns were used, with innovative "double-segment prefabricated pier column technology" enhancing construction speed while maintaining quality [7][9]. Group 3: Material Innovations - The research segment of the project utilized a high-performance steel-concrete composite structure for the last installed steel beam, achieving lightweight and high-strength characteristics through optimized material ratios and advanced prefabrication techniques [9][11]. - The use of thin-walled designs for prefabricated components effectively reduced the weight of the bridge's superstructure while improving crack resistance and durability [11]. Group 4: Strategic Significance - The project employs a composite design of "elevated mainline + ground auxiliary road," with the ground road expected to be completed by 2026, creating a comprehensive three-dimensional transportation corridor [13]. - This project plays a crucial role in enhancing connectivity between Nanjing and Zhenjiang, facilitating industrial collaboration and talent exchange, and supporting the integrated development of the two regions [16].