On December 10, the left line of the Wangjiazhai Tunnel, a critical control project of the Lincang-Qingshuihe Expressway (Linqing Expressway) in Yunnan Province, was completed. The project, undertaken by China Railway Tunnel Group, is considered a world-class challenge and a rare feat both domestically and internationally. The full operation of the expressway is now within reach.
The left line of the Wangjiazhai Tunnel is 8,010 meters long, constructed using a bidirectional tunneling method. The entrance is located in Linxiang District, Lincang City, and the exit in Shuangjiang County, Lincang City. Construction began in March 2018.
The tunnel’s geological conditions include Tertiary water-rich semi-consolidated rock, characterized by poor cementation, extremely soft rock, high saturation, desiccation cracking, poor water stability, and a high risk of disturbances causing sand collapses, mud outbursts, and soil flow.
The most challenging section is the 2.3-kilometer problematic geological zone on the Linxiang side, where tunneling feels akin to digging through a sponge—soft and water-absorbent. The key technical bottleneck was achieving solid-liquid separation.
