In recent years, due to the national promulgation of "nine safety tunnel construction", strict control of the number of people operating, operating requirements for mechanization and so on. More and more projects choose to use mechanized equipment for arch construction to improve the level of project construction. Among them, jiumian high-speed baima tunnel, contracted by sichuan luqiao group, has taken the lead in the mechanization reform.

Project description: the G8513 jiuzhaigou county to mianyang section begins at qinglong bridge (ganchuan boundary), guoyuan township, jiuzhaigou county, and ends at zhangjiaping, youxian district, mianyang city, with a total length of 241.295 kilometers. The designed speed is 80 km/h, and the subgrade width is 25.5 meters. When the jiumian expressway is completed, the journey from mianyang to jiuzhaigou will be shortened to three hours. The project is an important part of pingliang-mianyang highway, the yinchuan - kunming (G85) highway link in the national highway network planning, and occupies an important position in the national and regional highway network.

Jiumian high speed control engineering — & ndash; Baima tunnel is a double-line separated tunnel, with a length of 13013m for the left line and 13000m for the right line. The tunnel is a gas tunnel with large water inflow. The entrance construction is located at a steep mountain, with complicated geology, difficult conditions and difficult construction organization. In the construction process, the vault and side wall are easy to collapse, and the initial support is prone to large deformation,

In 2018, the baima tunnel project has been under construction for more than three years. In mechanized construction, such as wet spray manipulator, hydraulic trestle, automatic casting lining trolley and other equipment have been applied. However, during the construction of the project, the leader of the project department took the lead in realizing that the traditional manual method was still used in the arch erection process of the tunnel, which not only had high safety risk but also low construction efficiency. It is imperative to improve the technology and introduce mechanical equipment. Through the investigation and discussion, the baima tunnel project finally chose the tunnel multi-functional arch frame installation vehicle produced by the five new tunneling.

In November 2018, five new multi-function arch frame installation vehicles entered the field. At first, during the on-site training, there was no significant acceleration in the arch time due to the lack of familiarity with the new equipment. After only a few weeks of training, the workers gradually mastered the operation skills of the equipment, and their cooperation with each other became more orderly. Even during the operation, the workers summarized a set of their own construction skills.

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of construction of three truss-of-arch in baima tunnel

Baima tunnel adopts the full-section construction method. In the construction process of the multi-functional arch frame installation vehicle of the five new tunnels, 2 operators and 4 auxiliary workers are required. One person from each station on the left and right sides of the operation platform is responsible for operating equipment clamping, installing arch frames, welding mesh, etc. Ground support personnel 4 people, responsible for lifting the arch to the ground tripod, at the same time to deal with the arch foot gravel.

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During the construction, it took more than 20 minutes to clamp and install one truss, and when the first truss was installed, the ground support personnel lifted and connected the next truss in place, reducing the time of the whole process. In the connection of the arch frame, the bolts are not locked, so as to leave some adjustment space when docking, can be timely alignment.

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3 trusses of arches are installed during the period from equipment entry to departure. The total time is about 1 hour and 30 minutes. If the construction conditions are better, the time can be further shortened.

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Due to the excellent performance of the multi-functional arch frame installation vehicle in wuxin tunnel, the project department purchased another arch frame installation vehicle in October 2019 to provide services for the right entrance of baima tunnel. At present, the vertical arch technology of jiumian high-speed baima tunnel project has formed a demonstration effect, and has become the preferred site for each construction unit to investigate the mechanized vertical arch construction.

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At present, domestic tunnel construction “ Standardization, mechanization, specialization, informatization ” It is urgent to improve the level of tunnel construction, improve the safety and efficiency of tunnel construction, tunnel construction machinery instead of artificial is the trend of future development, five new tunnel multi-functional arch frame installation vehicle in the field of tunnel construction in China, will have a very broad market prospects.