The Sichuan Along-the-River Expressway starts from Xinshi Town in Yibin City and extends to the Jinjiang Interchange of G5 Beijing-Kunming Expressway on the east side of Panzhihua City. This route passes through four world-class hydroelectric stations and crosses several strong seismic fault zones. There are 219 bridges on the route, including 37 extra-large bridges, and 93 tunnels, including 35 particularly long tunnels.
The Qingping Tunnel No.1 is located in Qingping Yi Autonomous Township, Pingshan County, Yibin City, with a total length of 2616 meters, and is a two-way four-lane separated tunnel. The terrain and geological conditions of this tunnel are extremely complex. The rocks inside the tunnel are mainly carbonaceous mudstone and medium sandstone, with some coal seams interspersed. These rocks have poor cohesion, are thinly layered, and pose a high risk of gas control, making construction very difficult.
The Qingping Tunnel No.2 is also located in Qingping Yi Autonomous Township, Pingshan County, Yibin City, with a total length of 1634 meters, and is also a two-way four-lane separated tunnel. The terrain and geological conditions of this tunnel are similarly complex. The terrain at the entrance of the tunnel is extremely steep, with a slope of up to 80 degrees and a height difference of nearly 100 meters. The construction process requires traversing more than ten winding gravel roads from the provincial road to the construction site, with local slopes reaching 16% and a vertical rise of nearly 200 meters. The entrance road is very steep. The gravel soil at the entrance of the tunnel is loose, and the space of the construction platform at the entrance of the tunnel is extremely limited, making the site conditions very harsh. Inside the tunnel, there are mainly strongly weathered sandstone, karst filling material, and gravel soil, with many large karst caves and a daily water inflow of up to 13,000 cubic meters, posing high construction difficulty and safety risks.
The LanHi LDG312A intelligent arch frame integrated trolley adopts a lightweight design solution, with light weight and small size. The trolley integrates multiple processes such as measurement point setting, under-excavation operation, arch frame installation, welding mesh, and connection bars, and can complete the excavation and arch frame installation of a double-line tunnel at one go without moving the machine. The whole vehicle adopts an engineering chassis, diesel-electric dual-power system, bidirectional driving platform structure, good driving performance, and can adapt to various complex tunnel road conditions. The boom adopts wireless remote control operation, which is easy to accurately control the action of the mechanical arm and has the characteristics of fast, efficient, energy-saving, and safe.