On the first phase of Line 1, 17 shield machines are tunneling underground, and the prototype of the underground tunnel is taking shape... On March 1, Yang Zengkuan, Deputy Director of the Publicity Department of the Municipal Party Committee and Party Secretary and President of Lanzhou Daily, led key leaders and core reporters and editors from Lanzhou Daily, Lanzhou Evening News, and Lanzhou Newspaper New Media Center to visit Lanzhou Rail Transit Co., Ltd. to learn about the city's rail transit construction.

　　Main structures of 13 stations capped
　　At the symposium that afternoon, Duan Tingzhi, Party Secretary and General Manager of Lanzhou Rail Transit Co., Ltd., gave a comprehensive introduction to the city's rail transit construction from multiple aspects including the overall project planning, land acquisition and demolition, progress of the first phase of Line 1, and preparations for the first phase of Line 2.

　　The reporter learned from the meeting that the civil construction of the first phase of Lanzhou Rail Transit Line 1 is progressing smoothly. As of February 14, among the 20 stations on the line, the main structures of 13 stations including Olympic Sports Center Station, Century Avenue Station, Yingmentan Station, Matan Station, Tumen Dun Station, West Railway Station, Qilihe Station, Xiaoxihu Station, Cultural Palace Station, Xiguan Cross Station, Panxuan Road Station, Gongxingdun Station, and Donggang Station have been capped. The main structure construction of West Station Cross Station, Eastern Market Station, and Jiaojiawan Station is over 85% complete, that of Wulipu Station is 45% complete, and the main structure construction of Dongfanghong Square Station has begun; Chenguanying Station and Provincial Government Station are undergoing foundation pit earthwork excavation.

　　In addition, the steel grid assembly of the operation building at Chenguanying Parking Lot has been fully completed; the comprehensive building has entered the decoration stage; 95% of the total project investment has been completed. The station main earthwork excavation is underway at the part of Chenguanying Station where the site has been handed over.

　　On the morning of March 1, the interview team arrived at the Panxuan Road launching shaft construction site of the "Panxuan Road to Wulipu shield section" located east of Panxuan Road, opposite the Lanzhou University Computer City. Everything at the site was in order, and the hardened road surface was very clean. To minimize dust generated during construction, in addition to water spraying for dust suppression, all muck excavated during shield tunneling was covered with dust-proof nets.

　　Via the steel staircase connecting above and below ground, the interview team arrived at the Panxuan Road shield launching shaft more than 20 meters underground. Walking along the narrow construction walkway built on the wall of the left tunnel of the Panxuan Road to Wulipu section toward Wulipu, the tunnel was brightly lit, and after shield construction, the tunnel was formed in one pass. In the early spring season when it is warm yet still cold, although the temperature had risen, there was still a bit of chill, but inside the tunnel it was another world. 10 rings, 50 rings, 300 rings... 700 rings, as they went deeper, the temperature inside the tunnel rose higher and higher.

　　After walking for about 20 minutes, a "big guy" came into view. "This is the shield machine. When tunneling, its working principle is like a 'razor', using the cutters at the front to directly crush large-diameter cobbles, and the soil is cut down by the cutters on the rotating cutterhead, then squeezed into the soil chamber through the openings in the cutterhead..." the staff vividly explained the working principle of this "big guy".

　　The muck cut by the rotating cutterhead is transported backward along a specially made belt conveyor to the tail of the shield machine, and then carried out of the tunnel by rail battery locomotives. The so-called one-pass formation means that after the soil is cut, the segment erector picks up the segment and places it in the correct position, where it can be bolted to the previous segment. The other segments are installed in the same way until the entire ring is completed.

　　"The ground above our current location is the Gansu Provincial Health Vocational School," introduced the staff responsible for on-site construction. "The right tunnel of the Panxuan Road to Wulipu shield section has been completed, and the left tunnel where we are now has more than 40 meters to reach the endpoint."

　　Duan Tingzhi, Party Secretary and General Manager of the Municipal Rail Transit Company, introduced that currently there are 17 shield machines tunneling on the entire line. What is proud is that all 17 shield machines are produced and supplied by China Railway Construction Heavy Industry Group Lanzhou Tunnel Equipment Co., Ltd. in Lanzhou New Area. Lanzhou has thus become the second city in the country to use entirely local equipment for underground engineering, saving nearly 100 million yuan in costs compared with imported equipment, and after-sales service and spare parts replacement are more convenient and faster.

　　During the interview, the reporter learned that as of February 16, the cumulative tunneling of the entire shield section has reached 10,423 meters, accounting for 29.5% of the total project volume; the mined section from Gongxingdun to Jiaojiawan and from Jiaojiawan to Donggang has been excavated 2,371 meters, and the secondary lining construction has been completed 1,742 meters.

　　Remote monitoring "ensures safety and protects the blue sky"
　　As the largest project in Lanzhou's urban construction history, while ensuring construction quality and safety, it must also take into account the blue sky overhead.
At the video monitoring center of Lanzhou Rail Transit Co., Ltd., staff are conducting real-time monitoring of the construction site through more than 50 cameras distributed in various work areas of Line 1.
　　
　　According to introduction, at the beginning of the construction of the first phase of Lanzhou Rail Transit Line 1, the company drew on the experience of Beijing, Shanghai, Guangzhou, Shenzhen, Chengdu and other cities, and started early to establish the Lanzhou Rail Transit Engineering Safety Risk Information Monitoring Platform. The video monitoring system is one of the seven components of this platform.
　　
　　The system was completed and put into operation at the end of May 2014. Through high-definition cameras installed in each work area, it collects on-site construction information around the clock and uploads it in real time to safety information platforms at all levels. Staff at the monitoring center can view detailed conditions of the construction work face at any time without leaving the office.