Recently, with the successful breakthrough of the final layer of rock and soil, the left tube of the Longtou Tunnel of the Batai-Huanren Expressway Project (Section 8), invested in and constructed by China Railway (Liaoning) Benhuan Expressway Co., Ltd. and undertaken by China Railway Guangzhou Engineering Group, was successfully holed through. This marks the **th double-arch tunnel on the entire line to achieve breakthrough, 52 days ahead of the scheduled construction period.

The Longtou Tunnel is located in Dachuantou Town, Kuandian Manchu Autonomous County, Dandong City, Liaoning Province. It is one of the two double-arch tunnels on the entire line. The left tube is 300 meters long and is a shallow-buried tunnel. It adopts the CD construction method, which is slow in construction speed and high in safety risk. In response to construction difficulties and safety risks, the project team actively organized technical research, established a risk early-warning mechanism, and adopted advanced technologies and techniques such as advanced horizontal drilling, curtain grouting, wet spraying for initial tunnel support, and trolley cavity alarm, effectively overcoming difficulties such as tunnel water inrush, rockburst, and rockfall. On the premise of ensuring quality and safety, it adopted new techniques such as automated trolleys and prefabricated center partitions, efficiently organized construction production, and achieved the smooth breakthrough of the left tube.

It is reported that the Benhuan Expressway is a key infrastructure project planned and constructed during the "14th Five-Year Plan" period in Liaoning Province. After opening to traffic, it will form a rapid transportation network with a 3-hour traffic radius centered on Shenyang, while also improving the transportation network of the Liaodong region and even Liaoning Province, promoting the rapid development of tourism in the Liaodong region, accelerating the construction of the ecological tourism experimental zone in Liaoning Province, helping to enhance the locational advantages of Benxi, and promoting economic development.