Recently, the right tube of the Dayangan Tunnel on the Yunnan Tianma Expressway was successfully holed through, making it the first single-tube tunnel to be completed across the entire line.

The Tianma Expressway is located within Wenshan Zhuang and Miao Autonomous Prefecture. The route starts and ends at the Tianbao Port on the China-Vietnam border and terminates in Malipo County. The main line is 52.6 kilometers long, built to a two-way four-lane standard with a design speed of 80 kilometers per hour, and the proportion of bridges and tunnels reaches 88%.

The Dayangan Tunnel, whose single tube was holed through this time, is located in Dayangan Village, Malipo County. It is a separated tunnel, with the left tube 75 meters long and the right tube 155 meters long. The tunnel site area features low-mountain topography with considerable terrain undulation, and both the entrance and exit sections are located on steep slopes at angles of nearly 60°. "During tunnel construction, the project followed the principles of 'short advance, weak blasting, strong support, frequent measurement and rapid sealing,' and proposed a method for sectional construction of pipe roofs suitable for entering large asymmetrically loaded tunnels, avoiding large-scale excavation for tunnel entry and effectively reducing damage to the original ecology at the portal. Ultimately, the right tube was successfully holed through in 125 days," introduced the person in charge of the Tianma Expressway TJ-3 Section Project of CCCC Second Harbor Engineering Co., Ltd., which is responsible for tunnel construction.

After the project is completed and opened to traffic, the journey from Tianbao Port to the Malipo county seat will be shortened from the current 50 minutes to 20 minutes. The Tianma Expressway is an important component of Yunnan Province's medium- and long-term expressway layout of "five vertical, five horizontal, one side, two rings and twenty links." It will become an important corridor from Yunnan to Vietnam and Myanmar, and is of great significance for Yunnan to proactively serve and integrate into the Belt and Road Initiative, improve the local expressway network, optimize the structure of the interconnected regional road network, promote regional economic development and the building of demonstration zones for prosperity of border areas and enrichment of the people, and safeguard harmony and stability in border and ethnic minority areas.