Skip to content
Home » Kashima Automating and unmanning “slip-out” in mountain tunnel construction

Kashima Automating and unmanning “slip-out” in mountain tunnel construction

Automating and unmanning “slip-out” in mountain tunnel construction ~Improving safety and reducing manpower during shearing by leveraging automatic operation of wheel loaders~
Kajima (President: Hiromasa Amano) is proceeding with the development of the next generation automated mountain tunnel construction system “A4CSEL for Tunnel” (Quad Axel for Tunnel). During demonstration work at the Kamioka Test Mine (Hida City, Gifu Prefecture), we succeeded in automating a series of tasks from scooping up shear (rock debris) using an automatic wheel loader to transporting and unloading. Did. By linking this technology with a remotely controlled backhoe, it becomes possible to completely unmann the area near the working face, resulting in significant labor savings and dramatic improvements in safety.
[Image 1:×417.png ]
Shear transportation situation using automatic wheel loader
[Image 2:×323.png ]
Unloading situation by automatic wheel loader
Development background
[Image 3:×266.png ]
Concept of “A4CSEL for Tunnel”
In the construction industry, “lack of skilled workers,” “high incidence of industrial accidents,” and “low productivity” are urgent issues, and mountain tunnel construction is no exception.
Therefore, our company is proceeding with the development of “A4CSEL for Tunnel” to solve these issues. This system divides the excavation work for mountain tunnel construction into six construction steps: 1. Drilling 2. Charge/blasting 3. Shedding 4. Removal of hit 5. Shotting 6. Driving rock bolts, and the heavy equipment used in each step This is a next-generation construction production system that automates and centrally manages them.
Of these, 3. Shearing is the work of scooping up the shear generated at the face due to blasting using a wheel loader and loading it onto a transport machine or device such as a dump truck placed several tens of meters behind it. In standard tunnel construction, a wheel loader must make 40 to 60 round trips between the face and a dump truck, etc. per blasting process to remove the shear generated during blasting. It is dangerous because it approaches the face immediately after blasting, and combined with the work environment of traveling on a narrow and uneven roadbed, shearing is a task that places a heavy burden on the mind and body of technicians.
In June 2021, we succeeded in automating a series of tasks in a mock tunnel (Fuji City, Shizuoka Prefecture), from scooping up shear with an automatic wheel loader to loading it into a hopper. On the other hand, since the position and shape of the face changes each time, automating shearing in an actual tunnel requires solving problems unique to actual construction, such as securing a work route while avoiding contact depending on the situation. I had to go.
Overview and features of automated shearing
The machinery used in the shearing automation demonstrated in the Kamioka test tunnel consists of an automatic wheel loader, remote backhoe, hopper feeder (loading relay machine), and remote control room.
[Image 4:×1764.jpg] Mechanical configuration and work area for automated shearing The work procedure for automated shearing is as follows.
(1) An automatic wheel loader scoops up the shear scattered near the face due to blasting while accumulating it on the face side. (2) The automatic wheel loader moves backwards to the hopper feeder located 40 to 60 meters behind the face and injects shear. Shedding is automatically loaded onto a dump truck connected to a hopper feeder. (3) During the shear scooping process, the amount of shear remaining is estimated by measuring the weight of the scooped up shear using the automatic wheel loader’s sensor. When the amount remaining falls below a certain level, an operator in a remote control room collects the scattered scraps using a remote backhoe in order to maintain work efficiency (equalizing the amount scooped per operation by the automatic wheel loader). , continue to slide out
[Image 5:×1732.jpg] (1) Scooping up shear with an automatic wheel loader
[Image 6:×2925.jpg] (2) Adding shear to the hopper feeder
[Image 7:×2925.jpg] (3) Accumulation of shear by remote backhoe
[Image 8:×411.png ]
Automatic wheel loader monitoring screen in remote control room
[Image 9:×241.png ]
Automatic wheel loader self-position created using SLAM technology  Since satellite positioning systems (GNSS) cannot be used inside tunnels, it has been difficult to dynamically measure the position of machines inside tunnels. The newly developed automation system uses SLAM*2 technology to estimate the machine’s position in real time while creating a map of the mine from measurement data from LiDAR*1 mounted on an automatic wheel loader. As a result, we have established technology that can automatically operate within a tunnel, where conditions change with each blast, with an accuracy of within 30 cm of deviation from the planned route.
As a result of demonstration at the Kamioka test tunnel, we confirmed that it is possible to unmanned the area near the face during shearing, dramatically improving safety and relieving operators of work that is physically and mentally taxing.
*1 Irradiates laser light and measures distance etc. from its scattering and reflected light.
*2 Estimating your position and creating an environmental map at the same time the next deployment
In the future, we will continue to develop the technology so that it can be applied to more construction projects and types of work, with the aim of further improving the efficiency of the start-up process. Kajima will continue to work toward unmanned work areas through automation and remoteization of construction machinery, as well as creating rational operating procedures and operating methods suited to each task, and optimizing work plans for collaborative work involving multiple machines. We aim to improve efficiency.
Kamioka test tunnel construction overview
Location: Kamioka-cho, Hida City, Gifu Prefecture
Specifications: Tunnel excavation length: 321.3m Excavation
cross-sectional area: Approach section 43.9m2, automated construction test section 73.5m2
“Video of Kashima’s civil engineering technology” Mountain tunnel “A⁴CSEL for Tunnel” actual scale construction test in an actual mine tunnel has finally started
(Press release October 7, 2021)

Development of automated construction system “A⁴CSEL for Tunnel” for mountain tunnels
(Press release June 30, 2021)
More details about this release: