On July 29, after 14 years of arduous tunneling, good news came from the Dali-Ruili Railway, an important part of the China-Myanmar international railway corridor: the Dapoling Tunnel, located in a strong earthquake zone, achieved breakthrough.

The Dapoling Tunnel is located in Yongping County, Dali Prefecture, Yunnan Province, with a total length of 14.66 kilometers. The tunnel passes through seven large unfavorable geological zones. At the same time, the construction section is located in the strong earthquake zone of the Lancang River in southwest China. During the 14 years of construction, the tunnel experienced nearly 100 earthquakes of magnitude 3 to 6.

Facing various difficulties, all builders rose to the challenge. Starting with scientific construction, they invited experts to conduct a "consultation" on the special geological and topographic conditions, carried out advance detection, and promptly adjusted the excavation construction methods according to possible geological problems predicted. In response to different situations, they adopted methods such as advance small pipes, advance pipe roofs combined with steel supports for joint reinforcement, and glass fiber pre-reinforcement of the tunnel face, effectively reducing the impact of earthquakes and large deformation of soft rock on construction and increasing the tunneling speed from 60 meters to 85 meters per month.

The Dali-Ruili Railway is about 331 kilometers long and is an important project in China's Medium- and Long-Term Railway Network Plan for improving the road network layout and developing the western region. Once completed, it will end the history of no train service in ethnic minority areas such as Baoshan and Dehong in Yunnan. At that time, the travel time from Dali to Baoshan will be shortened from the current 2 hours by road to about 1 hour, and from Dali to Ruili from 6 hours to about 2 hours.