The 12.3 kilometer Xinhua Tunnel, part of the Dali-Lincang railway, was successfully connected on Tuesday. This is the first tunnel of such a length to be constructed in the Hengduan Mountains in Southwest China's Yunnan Province, the Xinhua News Agency reported.
After completion of the Dali-Lincang railway, the city of Lincang will finally be connected to the country's rail network. It will take just three hours to reach Lincang from Yunana's capital Kunming, improving the overall transportation system in the remote central and western parts of Yunnan. It will help improve transportation connections between China and neighboring countries.
The Dali-Lincang railway is 202 kilometers long with a top speed of 160 kilometers per hour. It is a national I-class electrified railway. Located in Nanzhang county, the Xinhua Tunnel is one of the most difficult projects along the route. Obstacles during the construction process included high water pressure, high geothermal heat, high seismic intensity and high ground stress.
The Xinhua tunnel passes through three faults. Temperatures inside the tunnel can reach beyond 40 C and to ensure safety and the normal operation of construction machinery, two 370 kilowatts super-powerful fans and around 10 tons of ice were used daily to reduce the heat.
