It's really fast! Shennong tunnel of Taijiao high speed railway is about to be paved

"When filling these construction reserved holes, they must be careful and free of gaps." Recently, at the construction site of "Shennong tunnel" of Taijiao railway near Xiba village, Bayi Town, Shangdang District, the person in charge of ballastless track bed construction carefully inspected the construction progress and urged the construction personnel to pay attention to the construction safety and quality. The Shennong tunnel, with a total length of 11.54 kilometers, is the most complex, risky and difficult to construct in the geology of Taiyuan Jiaotong railway. Among them, the length of the line in Shangdang District, Changzhi City is 4.9 kilometers, including the entrance work area of Shennong tunnel in Xiba village, Bayi Town and Shennong tunnel 1 inclined shaft work area in nanquanzhuang village. The exit of the tunnel is located in Shennong Town, Gaoping City.

since the start of the project, the China Railway Tunnel Bureau, which undertook the construction of the project, has scientifically arranged the construction scheme, reasonably allocated resources, further defined the target of the node construction period, adhered to the refined management and high standard construction, overcome a series of difficulties such as high safety risk, great construction difficulty and tight construction period, and successfully completed the connection task on January 18 this year. As one of the key projects of Taiyuan Jiaotong railway, the ballast bed construction technology of the whole ballastless track in Shennong tunnel is adopted. According to Yang Zhou, the Engineering Department of the project, ballastless track is a track structure that uses concrete, asphalt mixture and other integral foundations to replace granular ballast bed. It is an advanced track technology in the world. Compared with ballasted track, ballastless track avoids splashing ballast, has good smoothness and stability, long service life, good durability and less maintenance, but requires high precision during construction, and many construction surfaces need to be completed by fine adjustment of trolley. The construction surface of

tunnel is limited and the construction is difficult. The construction personnel carefully operate various construction machinery and carry out various construction operations in strict accordance with the engineering technical standards and operation requirements. At the scene, the reporter saw two 10 meter high gantry cranes almost the same width as the tunnel. Chen shuning, a staff member, said, "this is the machine used to pour concrete to the track bed that has already been supported." It turns out that before construction, workers should first bind the reinforcement mesh of ballastless track slab, and then transfer the prefabricated sleepers from the ground to the tunnel under the ground, and then use the special track array to position the sleepers one by one, and then pour the ballastless track slab. In order to seize the construction period, the ballastless track laying in the tunnel is carried out in 24-hour shifts. A 6031 a 6031 goes inside the tunnel to the maintenance area of the monolithic track bed. The monolithic track bed just poured is covered with membrane and geotextile. There are a lot of water drops on the geotextile, which should have just been watered. Chen shuning told reporters that the monolithic track bed is made of concrete, which needs to be covered for half a month and sprinkled twice a day. This is a very important link in concrete construction, which can improve the strength of concrete and prevent its cracking.

in the finished area of the monolithic track bed, engineers and technicians are manually filling the circular holes in the track bed. Chen shuning said that these holes are reserved for construction. At the end of the construction task of the monolithic track bed, it is necessary to fill them with high-strength mortar, and then polish them with a polishing machine to ensure the integrity of the monolithic track bed. At present, the construction of ballastless track bed of Shennong tunnel has been completed about 10 kilometers. Yang Zhou, the Ministry of engineering, said: "the ballastless track bed work of Shennong tunnel started on June 25, and the remaining one kilometer has been completed. That is to say, before the end of October, the whole ballastless track bed construction of Shennong tunnel has been completed in an all-round way. Although the time is tight and the task is heavy, the project department will overcome all difficulties, carry out construction with high standards, create first-class products and complete construction tasks with high quality. " (source: Shangdang financial media reporter: Jin Xiaoshu and Zhang Yanke)