Bayu tunnel, the first class high risk tunnel of Lalin railway, has been successfully connected

At 9:50 on November 2, with a blast, the Bayu tunnel, a key control project of Lhasa Linzhi railway, was successfully opened. The tunnel is classified as a first-class high-risk tunnel, which has set a record of 7015 meters of single head driving in the plateau railway tunnel The entrance of

Bayu tunnel is located in qusong Town, qusong County, Shannan City, and the exit is located in rasui Township, Gacha county. The main tunnel is 13073 meters long, the horizontal guide is 9481 meters long, the highest altitude is 3500 meters, and the maximum buried depth is 2080 meters. It is called "the tunnel with stones flying like shells" by the builders. During the construction, the highest ground temperature is 47 ℃, and 94% is located in the rockburst area Qiao Zhibin, director of Lhasa Railway Project Department of

12th Bureau of China Railway, said that rock burst is of high intensity and high frequency. Generally, rock burst lasts for 2 to 6 hours and lasts for more than a week at most. There will be a second rock burst even a few months after the rock burst, which is very rare in the world tunnel construction history. In addition, limited by special geographical conditions, the tunnel can not be set with auxiliary tunnel, only from the two ends of the inlet and outlet of the single head driving. The builder adopts the straight cut hydraulic blasting technology to carry out "weak blasting", and each working procedure adds a "stress release" link to minimize the frequency of rock burst and ensure safe and orderly driving The reporter of

learned that China Railway 12th Bureau and Chinese Academy of Sciences, with the theme of effective rock burst, analyzed and studied the ground stress, rock burst grade, rock burst warning and prevention in front of the tunnel, invented the dynamic layout technology of microseismic sensor array to track rock burst, and built the real-time microseismic monitoring of remote wireless communication transmission of rock burst on the Qinghai Tibet plateau for the first time Measurement system The

Lhasa Nyingchi railway is a key project of the 13th five year plan of the state, with a total length of 435.48 kilometers and a design speed of 160 kilometers per hour. It is the first electrified railway in Tibet. The geological conditions of the project are complex, and the bridge tunnel ratio is as high as 75%. At present, the project has entered a critical period of construction, and is expected to be completed and opened to traffic in 2021. At that time, it will not only effectively improve the layout of China's regional railway network, but also play an important role in promoting the development of economy along the line, improving people's livelihood, and promoting connectivity within and outside the region.