The S1 section of the Leshi Expressway is a new expressway, starting from Mabian and then connecting to the Renmu New Expressway's Mabian branch line, ending at Gudui Township in Leibo County, with a total length of 71.66 kilometers. This route passes through the Ma Bian East Wind Forest Farm. The S1-5 section of the Leshi Expressway in Gaozhuo Ying Township, Mabian Yi Autonomous County, Leshan City, is approximately 7.631 kilometers long, with 92% of the route consisting of bridges and tunnels. This section of the road has become an important part of the Leshi Expressway's entry into the uninhabited area for construction.
The Luoshanxi Tunnel of the Leshi Expressway is located in Gaozhuo Ying Township, Mabian Yi Autonomous County. It is a separated tunnel, with a single uphill direction throughout, with a gradient of 2.56%. The left line is 2,225 meters long, and the right line is 2,228 meters long. The net width of the tunnel is 10.75 meters, the net height is 7.15 meters, and the maximum burial depth reaches 311 meters. The main surrounding rocks are of grades IV and V. This tunnel is located on the southwest edge of the Sichuan Basin, connecting the transitional zone of the Yunnan-Guizhou Plateau, crossing very complex mountainous terrain and geological conditions.
The LanHi Multifunctional Tunneling Machine is a specialized equipment used for tunnel excavation. It primarily uses high-frequency hammers or breakers to break rocks, or utilizes bucket teeth or rod wedges to crush rocks, while also leveraging the gravity below the surrounding rock to automatically break rocks. This machine can be operated through local control or wireless remote control and is suitable for excavating tunnels with diameters ranging from 6 to 9.5 meters. It integrates functions such as high-frequency rock breaking, rapid excavation in soft soil, profile trimming, and spray dust removal, suitable for construction in areas where blasting is restricted, such as airports, residential areas, and wildlife reserves. This machine exhibits strong adaptability, capable of meeting various rock construction requirements while also minimizing issues such as over-excavation, under-excavation, and collapse.
During the project construction, the construction team overcame many difficulties, such as complex geological conditions, safety production, and ecological protection. They adopted the concept of "permanent convergence" and used the completed Xiaoliangshan Bridge as a construction platform to ensure the smooth construction of the Luoshanxi Tunnel of the Leshi Expressway. While ensuring safety and environmental protection requirements, they optimized the design of the Luoshanxi Bridge, reducing costs and shortening the construction period by 6 months. The project also introduced advanced technologies such as the tunnel information center control room and personnel positioning system, using equipment such as light-sensitive probes for comprehensive monitoring inside the tunnel to ensure construction safety. They also used wet spraying machinery instead of manual tunneling operations to effectively reduce risks, safeguard workers' health, and improve project quality. The project also actively practiced the concept of green expressway construction, avoiding damage to the original ecological vegetation caused by blasting construction by building tunnels and investing heavily in vegetation greening work.