as of September 15th, the China five Bureau of China Railway Company Lanzhou project department to undertake the construction of Lanzhou Xinjiang Railway second double heavy and difficult to control projects – Xining tunnel excavation exceed 5000 m mark, into a hole over 4700 meters, more than 85% of the amount of engineering design, construction has entered a stage of high and stable yield of the work.
Xining tunnel length of 5750 meters, is the second Lanzhou Xinjiang control throat engineering, complex geological conditions, the tunnel surrounding rock is weak, there are more than 1370 meters of the shallow buried section crossing the Lanxi highway, East District, village of Linjiaya village and small Beichuan River, and the water rich area, poor construction environment, the project risk is high, monitoring the difficulty is, the Ministry of Railways as first class high risk tunnel. In addition, the Xining tunnel continuous 1300 meters using double side heading method construction, which pioneered the five Bureau of China Railway Tunnel Construction Company in the history of precedent, comparable to the city subway.
started, the project department constantly sum up experience in construction management, to overcome the difficulties of shallow buried section, expansive rock mountain breakthrough bottleneck footage difficult. Strategically, the Xining tunnel is divided into mountain section and shallow buried section, which is adjusted according to the different assessment standards and the actual situation. Technical problems of project chief engineer personally imported shallow section, to ensure the safety of quality, and actively promote the new scheme, new technology, high requirement of 26 meters per month. The engineering department is responsible for solving some difficult technical problems of mountain footage, rock burst down, less than two weeks time, quickly solve the expansive rock drilling and blasting a new scale blasting technology of 3.5 meters to speed up the problem, the rapid advance of Xining tunnel. (author: Kong Xiangrui & Wen Yongguo)