On August 6, 2022, the No. 4 branch tunnel of Taihe Tunnel was excavated to the main tunnel of the second-phase project of the Daqiao Reservoir Irrigation District in Liangshan Yi Autonomous Prefecture, Sichuan Province, and successfully intersected with the main tunnel section. So far, all four branch tunnels of Taihe Tunnel have entered the main tunnel for construction, and important progress has been made in the excavation of Taihe Tunnel, a control project of the entire line.

The engineering design irrigation area is 458,500 mu, the total length of the new main and branch canals is 179.65 kilometers, and the installed capacity of the canal power station is 8150 kilowatts. Among them, the construction line has a total length of 176.69 kilometers, including 79 tunnels, 87.55 kilometers long; 54.73 kilometers of open canals; 7.8 kilometers of aqueducts, 7 inverted siphons (PCCP pipes), 7.54 kilometers long; 19.07 kilometers of culverts.

According to the person in charge of the second branch of the project, Taihe Tunnel has a total length of 12.05 kilometers and is the longest tunnel in the whole line. The maximum buried depth of the tunnel is 646 meters, and the maximum daily water inflow is 12,083 cubic meters. , high safety risks such as rock burst, water inrush, deformation and instability, and difficult construction.

After the completion of the second-phase project of the Daqiao Reservoir Irrigation District in Liangshan Prefecture, it will send the water of life to 450,000 mu of farmland, moisten the three counties (cities) of Mianning, Xichang and Dechang, and solve the problems of high-quality drinking water and irrigation for millions of people along the line.Editor/Ma Xue