(TibetanReview.net, Apr08’20) – China said Apr 7 it had achieved a major progress in the building of the Lhasa-Nyingchi railway within Tibet Autonomous Region with the completion of the building of all 47 tunnels under the project. The project is part of the mammoth Sichuan-Tibet Railway which is expected to open Tibet for massive influx of Chinese settlers. The Lhasa-Nyingchi section is expected to open next year.
Construction on the last two of the 47 tunnels on a 435-km railway linking Lhasa and Nyingchi (Tibetan: Nyingtri) was completed on Apr 7, marking huge progress for the mammoth project, reported China’s official Xinhua news agency Apr 7.
One of the tunnels completed was stated to be the Mainling Tunnel, located in the city of Nyingchi. It is 11,560 metres long with an average elevation of 3,100 metres above sea level and a maximum burial depth of about 1,200 metres. It is believed to be one of the most difficult tunnels ever built, the report added.
The other was stated to be the 8.7-km Zagar Tunnel in the city of Shannan (Lhokha), which traverses seven faults of complex geological structures, including one of the thickest water-rich moraine layers, the report said.
“Rockbursts occurred in about 65 per cent of the tunnel, or 7,500 meters, causing high safety risks,” He Xu, a director of the project, was quoted as saying. “During the construction of certain sections, the rocks burst like loaded guns, threatening the workers’ lives.”
Workers were also stated to have frequently encountered noxious gases.
The report cited Yang Zeng, a chief engineer of the Zagar Tunnel, as saying it took over two years to overcome the engineering roadblocks brought by the 960-meter-thick water-rich moraine layer in the tunnel.
The report said the completion of the two tunnels on the Lhasa-Nyingchi railway had increased the total tunnel length to 216.5 km, almost half of the railway’s length.
The report said 75 per cent of the railway was bridges and tunnels, with over 90 per cent of the railway being at over 3,000 metres above sea level on the Qinghai-Tibet Plateau.
The report said over 20,000 builders had been working on the railway since the end of 2014.
As of Apr 7, a total of 119 bridges had been built, leaving just one bridge to be completed, the report said. Also, about 115 km of tracks had been laid, with the rest to be completed by the end of this year.
The first electric railway in the region with a designed speed of 160 km per hour will be completed and put into operation in 2021, the report said.