包银高铁银巴支线贺兰山隧道贯通

Core Viewpoint - The successful completion of the Helan Mountain Tunnel marks a significant milestone in the construction of the Baoyin High-speed Railway, which is a crucial part of China's national high-speed rail network [1] Group 1: Project Overview - The Helan Mountain Tunnel, constructed by China Railway Fifteenth Bureau, has a total length of 8,792 meters and is located at the boundary between Alxa Left Banner in Inner Mongolia and Yinchuan in Ningxia [1] - The tunnel's geological conditions are extremely complex, with a maximum burial depth exceeding 230 meters, and it requires passing under six fractured zones and the Ming Great Wall, categorizing it as a Class I high-risk tunnel [1] Group 2: Construction Techniques - To minimize disturbance to the Ming Great Wall, the construction team upgraded traditional blasting methods to a low-disturbance combination technique involving "mechanical excavation + C6 drilling machine operation + dynamic monitoring," ensuring high-quality and efficient tunneling [1] Group 3: Strategic Importance - The Baoyin High-speed Railway is an important component of the national "Eight Horizontal and Eight Vertical" high-speed rail network, with the Yinba branch line starting in Yinchuan and ending in Bayannur, Inner Mongolia [1] - The Helan Mountain Tunnel is identified as a critical and challenging control project within this branch line [1]