Modern Express News (Correspondent Huo Wei, Lin Feng, Reporter Liu Weijuan) On May 13, the "Ningwu" shield machine with an excavation diameter of 9.33 meters was successfully rolled off the assembly line in Changsha City, Hunan Province, and will arrive in Nanjing in the near future. The Modern Express reporter learned that the shield machine will be used for the shield section of the Nanjing South Tunnel of the Ningwu Railway Expansion and Reconstruction Project. This marks important progress in the construction of the Ningwu Railway Expansion and Transformation Project.
△ Ningwu railway route map. Photo courtesy of correspondent
Nanjing South Tunnel is a full-line control project of the Ningwu Railway Expansion and Reconstruction Project, spanning Qinhuai District, Yuhuatai District and Jiangning District of Nanjing, and passing through Ning'an High-speed Railway, Beijing-Shanghai High-speed Railway, Shanghai-Rong Railway and other trunk railways, as well as Ningdan Highway, Niushou Avenue and other traffic arteries. The tunnel has a total length of 14.442 kilometers and is a single-hole single-track tunnel with a design speed of 120 kilometers per hour, of which the shield section is about 2.4 kilometers long, and is constructed by an earth pressure balance shield machine.
△ The "Ningwu" shield machine was successfully rolled off the assembly line for acceptance. Photo by Zheng Tao
Shao Xiaoming, technical director of the second division of the Ningwu Railway Project of the 14th Bureau of China Railway, introduced that the tunnel shield section starts from the working well of Meixiang Road, Yuhuatai District, and ends at the existing tunnel reception in Hanfu Mountain, Jiangning District, and then crosses the Nonghua River and the Airport Expressway, crosses the S1 subway line, and runs parallel to the S3 subway line for a long distance, and crosses the existing tunnels of the Qinhuai Xinhe and Hanfushan Beijing-Shanghai high-speed railways, etc., and passes through argillaceous sandstone, silty sandstone and other strata, which have the characteristics of many waters, complex surface and underground environment. In particular, the shield machine passes through the Qinhuai New River section, and the shallowest overburden is only 2.6 meters, which is the shallowest overburden encountered in the domestic shield project.
△ Technicians carry out offline acceptance of the shield machine. Photo by Zheng Tao
In view of the characteristics of many construction difficulties, high safety risks and complex technical conditions in the shield section of Nanjing South Tunnel, the construction management unit of the project, Hefei Railway Hub Project Construction Headquarters, together with China Railway 14th Bureau and other participating units, jointly developed and manufactured the "Ningwu" shield machine in Changsha Shield Industrial Base with China Railway Construction Heavy Industry Group. The shield machine excavation diameter of 9.33 meters, the total length of the whole machine is 132 meters, the weight is about 1375 tons, the total installed power is 4305 kilowatts, in the cutterhead structure, cutter layout, muck transportation, excavation control, shield tail detection and other aspects of targeted improvement, the application of excavation bin visual system, shield tail brush wear detection system and other advanced intelligent technology. At the same time, the shield machine is equipped with wear-resistant toothed hobs, single-pipe single-pump muck improvement system, continuous belt conveyor, etc., which will realize the effective control of shield construction risks, comprehensively improve the tunneling efficiency, and fully demonstrate the advanced level of high-end intelligent equipment for railway construction.
△ Acceptance and commissioning are carried out in the operating room of the shield machine. Photo by Zheng Tao
In order to highlight the characteristics of the railway, the cutterhead design of the "Ningwu" shield machine is painted with a locomotive pattern, with red and yellow colors as the keynote, implying that the old railway will achieve a "new look" through new technologies such as shield construction.
It is reported that the Ningwu Railway is mainly freight, taking into account a small amount of passenger transport, and is an important infrastructure to enhance the freight capacity of the eastern section of the Yangtze River Economic Belt and an important part of the railway corridor along the Yangtze River. The Ningwu Railway Expansion and Reconstruction Project starts from Nanjing East Marshalling Station (not included) in the north, enters Ma'anshan City of Anhui Province through Qixia District, Qinhuai District, Yuhuatai District and Jiangning District of Nanjing City, passes through Dangtu County into Wuhu City, and ends at Wuhu East Station (not included). After the reconstruction, the total length of the line is 102.2 kilometers, of which the new outer winding and realignment project from Cangbomen Station to Guxiong Station in Nanjing City is a new outer bypass realignment project, with a length of 29.7 kilometers, and the remaining sections are electrified and expanded, with a main line length of 72.48 kilometers. After the project is completed and put into operation, it will further optimize the layout of the regional railway network, which is of great significance for implementing the concept of "ecological priority and green development", accelerating the upgrading and adjustment of the industrial structure of the regions along the line, optimizing the spatial layout of urbanization, and enhancing the flexibility of the road network.