The first unmanned urban railway in China has begun its trial run! Viaduct is assembled by prefabricated segments

On September 8, with the unmanned vehicle driving out of Xuchang East Station, the Zhengzhou-Xuchang Municipal Railway, which was built by the China Railway 16th Bureau, began its no-load trial operation, laying a solid foundation for its official opening. The Zhengzhou-Xuchang Municipal Railway is the first unmanned urban railway in China and the first unmanned rail transit line in Henan Province.

The Zhengxu Municipal Railway starts from Zhengzhou Xinzheng Airport Comprehensive Transportation Transfer Center in the north and ends at Xuchang East Station of Beijing-Guangzhou High-speed Railway in the south, with a total length of 67.13 kilometers. The line connects Xinzheng Airport, Zhengzhou Airport Economic Comprehensive Experimental Zone, Changge and Xuchang, runs through the core area of the Zhengzhou-Xuchang industrial belt in the Central Plains urban agglomeration, and is connected to the Zhengzhou subway network.

"The Xuchang section of the Zhengxu City Railway is the largest single project invested in Xuchang City since the founding of the People's Republic of China, and it is also a leading project to accelerate the process of 'Zheng-Xu integration' and promote the construction of the Central Plains urban agglomeration. After completion, Xuchang will officially open a new era of rail transit." said He Jijun, chairman of Xuchang Construction Investment Co., Ltd.

According to Xia Lei, commander of the Zhengxu City Railway Engineering Headquarters of the China Railway 16th Bureau, different from the traditional large-volume box girder, the viaduct of the Xuchang section of the Zhengxu City Railway is assembled with small-volume segment box beams. The prefabricated sections need to be produced in sections in the prefabricated beam yard in advance, hoisted on site by a bridge erecting machine, and assembled in the form of "building block assembly".

"We actively responded to the national concept of green prefabricated building construction, and used BIM technology, big data, and the Internet of Things to build a 'smart beam field' covering an area of about 300 acres. The production, storage and maintenance of 736-hole and 8640-segment beams have been completed. The factory-like organization of production is convenient for overall quality control and helps to protect the surrounding ecological environment. "Hao Wenchao, Secretary of the Party Working Committee of the Zhengxu City Railway Engineering Headquarters of the China Railway 16th Bureau, said, "In addition, the steel bars, formwork and concrete processes in the prefabrication link have been produced in workshops, forming a mature segmental beam prefabrication construction process."

During the construction, the segmental beams are prefabricated by the method of "curve beam and curve", and are produced by the short-line matching method. Compared with the technology of cast-in-place section + segmental prefabrication on the top of the pier, which is commonly used in segmental beams in the industry, the whole-hole prefabrication has more precise requirements on the linear quality of the beam body. In order to overcome this technical difficulty, the construction team of China Railway 16th Bureau dispatched mature technical backbones to form a technical special class, and carried out technical research on prefabricated formwork system, three-dimensional linear monitoring technology, comprehensive maintenance technology and information technology. And jointly developed the linear control software "Precise Measurement Control APP" with the project design unit Tie Siyuan, fully considering the linear parameters in the production stage. By adjusting the coordinates of the matching segments, the splicing accuracy of the matching joints of adjacent beam segments is ensured, the segment beam production accuracy is 100%, and the assembled line shape is completely consistent with the design line shape.

"We innovatively applied the 'overhead catenary + special return rail' grid-rail hybrid traction power supply system, which solved the technical problem of stray current corrosion from the root." According to Liang Zhengang, head of the Zhengxu Project of the Electrification Company of the China Railway 16th Bureau, the Zhengxu Municipal Railway "Four Electricity" project applies a number of new technologies, and the signal system adopts the current highest-level GOA4 driverless technology to achieve full-featured automatic operation control. The Xuchang section adopts the energy storage regenerative energy absorption technology, and innovatively applies the four-rail return technology in the power supply system to effectively solve the stray current hazards.

The construction team not only actively carries out technological innovation, but also adopts a number of measures in construction management to strictly control the "green environmental protection" of the project. "The construction line traverses the Shuangji River National Wetland Park. By setting up a steel trestle as a construction platform, we chose to carry out construction during the dry season to maximize the protection of the topography." Fang Zhiqiang, deputy chief engineer of the Zhengxu Municipal Railway Engineering Headquarters of the China Railway 16th Bureau, said. The construction team focuses on fighting the blue sky defense battle. On the basis of the "six hundred percent" requirement for dust control in Henan Province, two measures have been added, including "100% recycling of waste concrete and 100% dust reduction by spraying along the fence" to achieve "eight hundred percent", which achieved "eight hundred percent" and achieved "zero accidents" in the dust control work.

It is reported that the no-load trial operation will last for 3 months. After the safety assessment, it will be put into operation to carry passengers, and the "railway public transportation" operation with high density and short marshalling will be adopted. It will speed up the process of "Zheng-Xu integration", vigorously promote the construction of the Central Plains urban agglomeration, and drive the economic and social development of the regions along the route.