Yiliang County in Zhaotong City, Yunnan Province, lies deep in the Wumeng Mountains, where high mountains and deep valleys make transportation the biggest obstacle to local economic and social development. In 2019, construction began on the Yunnan section of the Chongqing–Kunming High-Speed Railway, and tens of thousands of railway builders converged here. As the Spring Festival of the Year of the Rabbit approached, in order to complete the railway as soon as possible and benefit the local area, many work sites on this railway kept working through the holiday, and thousands of railway builders chose to celebrate the New Year where they work. During this year's Spring Festival, the reporter visited the Yiliang Tunnel on the Chongqing–Kunming High-Speed Railway.

The Yiliang Tunnel lies deep in the Wumeng Mountains, where high mountains and deep valleys make the terrain extremely steep and rugged. It is a controlling project on the entire Chongqing–Kunming High-Speed Railway line. The Yiliang Tunnel is a double-track, separately built twin-bore single-track tunnel, with the left bore 24.78 km long and the right bore 24.8 km long.

Wang Xutao, 28, is the on-site technical supervisor of No. 2 inclined shaft of the Yiliang Tunnel. His organization undertakes the construction task of Section 1 of the Yunnan–Guizhou portion of the Chongqing–Kunming High-Speed Railway. On January 21, New Year's Eve, Wang Xutao, as usual, got up early and began a busy day.

Wang Xutao (first from right) at work

"Old Wu, the surrounding rock at this section of the tunnel face is not in good condition. When you lead the shift, be sure to give clear instructions: strictly control the depth of the blast holes and the charge weight, keep an eye on changes in the surrounding rock at all times, and pay close attention to safety." At the tunnel face of No. 2 inclined shaft of the Yiliang Tunnel, Wang Xutao repeatedly reminded shift foreman Wu Kai.

Tunnel construction runs 24 hours without interruption. After the advance support crew finished its work, it was the turn of the excavation crew. Wang Xutao went with them to the tunnel face to inspect the night shift's work.

"Tunnel construction is one process after another, a continuous cycle, and no process allows the slightest carelessness. Taking a look on site gives me a comprehensive grasp of the night shift's progress, quality and process coordination, and then I have confidence when arranging and organizing the day's construction production," Wang Xutao explained.

According to Wang Xutao, the Yiliang Tunnel is a key controlling project on the entire line, and the time of its breakthrough restricts the time when the whole line can be completed and opened to traffic. At present, all work sites of the Yiliang Tunnel have entered main tunnel construction. Due to geographical constraints, mechanical equipment, the entry of raw materials and the hauling of spoil all pose obstacles to the schedule.

Access road for the Yiliang Tunnel project (the "13 Hairpin Bends" scenic spot)

The portal of No. 2 inclined shaft of the tunnel is located at the bottom of a valley with a vertical drop of 600 meters. To ensure that mechanical equipment, raw materials and tunnel spoil can enter and exit smoothly, a 7.5-kilometer access road had to be built from the mountaintop downward. The construction access road, built along the mountain contours, has 13 turns, so netizens vividly call it the "13 Hairpin Bends" scenic spot, and it has even become an internet-famous photo spot.

To break through the tunnel as soon as possible without affecting subsequent construction, many builders have made arduous efforts. During the Spring Festival, in Work Area 2 of Section 1 of the Yunnan–Guizhou portion of the Chongqing–Kunming High-Speed Railway alone, more than 400 builders stayed on the construction front line. Wang Xutao's wife, Song Yaming, is a site records clerk responsible for collecting, summarizing and compiling project documents. Although the couple works on the same project, they actually do not have many chances to meet.

"We got married in June 2022. Although we are in the same project department, he is at the work area and I am at the project department, so in fact we see each other once a week. We gave the chance to go home for the New Year to colleagues who have children or elderly parents. Staying at the construction site for the New Year will be more memorable," Song Yaming said with a smile.