On April 9, the exit section of the Yingpanshan Tunnel on the Huali Expressway, constructed by China Construction Seventh Engineering Division, successfully broke through to the No. 2 inclined shaft, marking a key victory in the Huali Expressway project and laying a solid foundation for opening to traffic by the end of 2021.

　　The Yingpanshan Tunnel is one of the controlling projects of the Huali Expressway, with a total length of 11.28 kilometers. It is a high-risk tunnel located in the hinterland of the Hengduan Mountains on the northwestern Yunnan-Guizhou Plateau, with a maximum buried depth of 877 meters. It is situated in densely jointed and fractured rock masses and structural fracture zones, with a maximum daily water inflow of up to 100,000 cubic meters, equivalent to the water volume of 40 standard swimming pools. Above the tunnel is a coal mining goaf, and the lowest point of the roadway is only 92 meters from the tunnel crown. The geological and hydrological conditions are extremely complex, with high risk levels, great construction difficulty, and strict construction requirements.

　　In response to the complex and variable surrounding rock geology of the Yingpanshan Tunnel and major adverse geological risks such as water inflow, mud outbursts, deformation, karst, rock bursts, and gas, the project team promoted the transformation and application of a series of innovative achievements including new processes, new equipment, and new technologies in water discharge construction during dynamic construction. They conducted numerous expert demonstration meetings, scheme comparison and optimization, and scientific research. According to the surrounding rock conditions and risk levels of different sections of the tunnel, corresponding targeted comprehensive prevention and control measures were taken, construction schemes were dynamically adjusted, and construction organization was scientifically optimized. During construction, comprehensive exploration methods such as three-dimensional geological radar, mobile drilling, and advanced horizontal drilling were used to identify the distribution of major faults, karst, and other adverse geological conditions and their impact on the tunnel. Comprehensive treatment schemes such as water discharge efficiency, pre-reinforcement of fracture zones, optimization of drainage systems, and strengthening of support systems were proposed in a timely manner, overcoming technical difficulties such as high water pressure, mud and water outbursts, and large deformation of soft rock. At the same time, "standardized design and construction" was implemented, and complete sets of equipment such as secondary lining thickness pre-inspection trolleys and wet spraying manipulators were equipped to help create a premium demonstration project.

　　As a key project of the "Belt and Road" initiative, the Huali Expressway passes through the residential areas of multiple ethnic minorities such as the Yi, Shuitian, Lisu, and Dai. Upon completion, it will play an important role in promoting regional development in northwestern Yunnan, poverty alleviation and development, and driving the development of tourism and other industries. It will open up the transportation lifeline for residents along the route, benefiting 1.1 million people of all ethnic groups along the line.