Recently, the left tube of the Tianfuwan Tunnel on the Lichuan-Xianfeng Expressway in Enshi, Hubei, constructed by CCCC Second Harbor Engineering Co., Ltd., was successfully holed through. This is the first long tunnel to be holed through along the entire Lixian Expressway.

　　The fourth bid section of the Lixian Expressway project comprises a total of 5 tunnels, of which the Tianfuwan Tunnel is the second longest. Its entrance section is located in Lizixi Village, Xiaocun Township, and its exit section in Shabaoxi Village, Tangya Town. The left tube is 2,515 meters long with a maximum buried depth of 386.64 meters, and the right tube is 2,635 meters long with a maximum buried depth of 388.99 meters. Construction is carried out by two-way excavation from both the entrance and the exit.

　　The area where the Tianfuwan Tunnel is located features tectonic erosion-denudation mid- and low-mountain topography. The surrounding rock consists of moderately weathered sandy shale intercalated with shale; the rock mass is relatively fractured, has weak water yield, and poor self-stability, making roof collapse highly likely. To ensure safe and smooth excavation of the tunnel, the project department organized meticulously and planned scientifically, strictly following the construction principles of "advanced pipe forepoling, weak blasting, strong support, frequent measurement, and early closure." At the same time, it established and improved a tunnel advanced geological forecasting system, carried out full-process tunnel monitoring and measurement to guide on-site construction, and applied new equipment and new processes such as wet-spraying robotic arms, semi-automatic waterproofing and drainage laying trolleys for secondary lining, and automatic distribution trolleys for secondary lining with formwork grouting, ensuring reliable safety and quality of the project.

　　The Lixian Expressway project is a major transportation artery that opens up the core area of the Wuling Mountains spanning Hubei, Hunan, Chongqing, and Guizhou. Once completed, the driving distance from Lichuan to Xianfeng will be shortened from 2.5 hours to 1 hour, effectively solving the rapid travel problem for nearly 400,000 people in Lichuan and Xianfeng counties, and is of great significance for driving the development and utilization of clean energy, ecological and cultural tourism, and other resources in the Wuling Mountain area.