Humaling Tunnel, the "No.1 key and difficult project" in lanzhou-chongqing railway, which was praised by tunnel experts at home and abroad as "rare in China and difficult in the world", was successfully completed on June 5438+09, marking the final stage of the opening of lanzhou-chongqing railway.
Lanzhou-chongqing railway is the backbone of the railway network in western China, connecting the Yellow River and the Yangtze River, an important "steel" bridge between the Lan Xin Economic Belt and the Sichuan-Chongqing Economic Belt, and an important traffic artery along the Belt and Road. After lanzhou-chongqing railway is completed and opened to traffic, the trains from Europe and Xinjiang to Chongqing via Lanzhou will no longer need to bypass the Longhai, Xikang and Xiangpu railways, becoming one of the three north-south railway arteries alongside the Beijing-Guangzhou line and the Beijing-Shanghai line, and also an important passage between the western region and the Pearl River Delta and Yangtze River Delta regions.
Lanzhou-chongqing railway, known as "geological museum", is a long mountain trunk railway with the most complicated geological conditions in China. Humaling Tunnel, built by China Railway Construction 19th Bureau Group, has a total length of 13.6 km, which is the most difficult section and the last node project in lanzhou-chongqing railway. Tunnel geology is mainly composed of tertiary mudstone, sandstone mixed with mudstone and water-rich silty fine sand, and the water content of silt is as high as 24%. Humaling tunnel construction is like digging in soft tofu and constructing in mud. Traditional grouting and drainage measures are not effective. In the process of construction, if you dig and flow, the tunnel will deform and collapse. Especially, the area between 1 inclined shaft and No.2 inclined shaft is the tertiary water-rich silt high-pressure water-rich area, and there have been four large-scale water inrush and mud gushing, with a total of 50,000 cubic meters of sand, 6.5438+0.5 million cubic meters of mud and 800,000 cubic meters of water.
In view of this difficulty, since the start of Humaling Tunnel in 2009, various scientific research institutions, Chinese and foreign experts and academicians have entered the market to find the best scheme. After several years of construction, exploration and scientific research, through 100 expert meetings and thousands of process tests, the construction problems have been solved continuously.
Wang Xuezhong, chairman of the 19th Bureau of China Railway Construction, said that new technologies such as "vacuum dewatering" were adopted in the construction, which effectively overcame the flood of water inrush and sand gushing, reliably ensured the construction safety and achieved the goal of treating both the symptoms and root causes.