The first ten thousand meter long tunnel of Dalin railway runs through

Our correspondent Jiang Zhuocheng, correspondent Zhang Weiming, reported yesterday that after nearly four years of hard work by railway builders, Xinhua tunnel, the first long tunnel with a length of more than 10 kilometers from Dali to Lincang railway, was successfully completed, marking a major breakthrough in the construction of key and difficult control projects along the line.

Xinhua tunnel with a total length of 12.3km is a key and difficult control project of China Myanmar international channel Dalin railway, which is located in Nanjian County, Dali Prefecture. The tunnel passes through the junction of Wuliang Mountain and Ailao Mountain in Hengduan Mountain range. The mountain range is vertical and horizontal, the terrain is precipitous, the valley is deep, and the geological structure is extremely complex. It belongs to the national level I high-risk tunnel. In the process of construction, the construction headquarters of West Yunnan Railway of Kunming Railway Bureau Group of China Railway organized the participants to overcome many problems, such as high water pressure, high heat, high seismic intensity and high stress. "Below the tunnel exit is the Lancang River, and above the slope is a large reservoir with a water storage capacity of 15 billion cubic meters. The whole construction work is basically carried out more than 100 meters below the water level of the reservoir, which is equivalent to a huge pressure of 15 billion cubic meters of water. The tunnel is very permeable with a maximum daily inflow of 70000 cubic meters. In order to avoid mud inrush and water inrush, the builders used seismic wave, infrared water detection, transient electromagnetic and other methods to pre detect the geology in advance, and set up a three-stage pump station with double pipeline and anti slope pumping to ensure the safe tunneling of the tunnel. " Zhao fan, manager of the third work area of Dalin Railway Project Department of China Railway 12th Bureau, said.

in the "waterfall gathering" environment, the high temperature and humidity also test the construction personnel. The maximum temperature in the tunnel can reach more than 40 degrees, just like a "sauna room". Every day, two 370 kW super power fans continue to relay air supply, and 10 tons of ice blocks cool down day and night, so that construction personnel and mechanical equipment can maintain normal construction operations.

through the establishment of information linkage mechanism with the monitoring departments of earthquake, safety, quality and so on, the construction party takes the smart phone terminal as the carrier, effectively combines the information technology with the project construction, implements a series of information measures such as "full coverage of the face network" and "remote visual monitoring", providing guarantee for the construction safety and quality. Through field measurement, the vertical error of the tunnel is 7mm, the horizontal error is 12mm, and the construction accuracy is higher than that of similar long tunnels.

is a 202 km long Dalin railway, which is an important part of China Myanmar international channel. The design speed is 160 km / h. After completion and opening to traffic, Kunming Lincang railway can reach about 3 hours, which is of great significance to boost the interconnection between Southwest China and surrounding countries.