下穿昆明长水机场跑道，渝昆高铁重难点控制性工程贯通

Core Viewpoint - The successful completion of the Changshui Airport Tunnel marks a significant breakthrough in China's high-speed rail construction, particularly in complex geological and sensitive environmental conditions [1][2]. Group 1: Project Overview - The Yukun High-Speed Railway spans approximately 700 kilometers and is a crucial part of the "Eight Vertical and Eight Horizontal" high-speed rail network, significantly reducing travel time between Chongqing and Kunming upon completion [1]. - The railway's segment in Yunnan Province is 388.6 kilometers long and is the first high-speed railway in the province designed for a speed of 350 kilometers per hour, with a high bridge and tunnel ratio of 87.4% [1]. Group 2: Technical Challenges and Innovations - The Changshui Airport Tunnel, measuring 8,770 meters, passes under sensitive structures including the airport's operational area and existing railways, presenting unique geological challenges such as fractured rock and karst development [1][2]. - Traditional blasting methods were avoided to minimize impact on airport operations; instead, advanced cantilever tunneling machines were employed, making this the longest continuous section using this method in China at 4,145 meters [2]. Group 3: Project Progress - With the completion of the Changshui Airport Tunnel, 43 tunnels have been completed in the Yunnan section of the Yukun High-Speed Railway, achieving over 80% completion of the tunnel work [3]. - The project is now in the final stages, with the main structures of the roadbed, bridges, and tunnels nearly complete, while the subsequent electrical and station works are progressing rapidly [3].