China News Service, Xining, April 9th (Reporter Zhang Tianfu) The reporter learned from the Qinghai Provincial Traffic Control Group on the 9th that the right hole of the Lehua Tunnel of the Lehua Expressway Project was successfully connected, marking the first difficult control project of the project. Significant progress has been made.
The picture shows the entrance of Lehua Tunnel. Photo courtesy of Qinghai Provincial Traffic Control Group
The Lehua Tunnel is located in Qutan Town, Ledu District, Haidong City, and Bayan Town, Hualong County, Qinghai Province. It is the highway tunnel with the largest burial depth (740m) in Qinghai Province and the third longest tunnel in Qinghai Province. Construction management is difficult and safe. The risk is high.
It is reported that the total length of the right line of the tunnel is 5,933 meters, all of which are grade IV and V surrounding rocks, of which grade V accounts for 74.2% and grade IV accounts for 25.8%. The average altitude of the tunnel site is 3,500 meters. The regional topography, geology, and hydrological environment are complex and unfavorable. The main geological phenomena include fault fracture zones, extreme geostress and seasonal frozen soil. The fault fracture zones were passed through five times during the excavation process.
Since the construction of the tunnel started, all the construction personnel have overcome a series of difficulties such as high cold and hypoxia at the construction site, complex geological conditions of the tunnel, rich water, difficult construction management, and high environmental protection requirements. In only three and a half years, nearly 6,000 tunnels have been completed. The excavation task of 100,000 square meters has created the "Lehua Speed" of high-quality tunnel construction in the province.
The smooth penetration of the right tunnel of the Lehua Tunnel has created favorable conditions for the full penetration of the Lehua Tunnel and the early opening of the project. After the completion of the Lehua Expressway, it will realize the regional high-speed "network", promote the interconnection between Haidong City and various counties and districts, give full play to the benefits of the expressway network, improve Qinghai Province's external development space, improve traffic conditions along the route, and enhance Radiating ability, it is of great significance to promote the tourism development of Qutan Temple and other places. (over)