Concrete spraying support system

Abstract

To provide a concrete spraying support system capable of indicating a proper locus to move a spraying nozzle for automatization of spray work for solving a problem in a prior art.SOLUTION: A concrete spraying support system of the present invention for supporting concrete spraying performed on a surface to be sprayed for tunnel excavation, comprises diffusion area calculation means and nozzle locus setting means. The nozzle locus setting means sets a plurality of line segments almost parallel with each other as individual loci, calculate a width of strip-like concrete on which concrete is spayed along each of line segments based on a diffusion area, and further sets intervals between the individual loci based on the width of the strip-like concrete.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to sprayed concrete, one of the support methods used in tunnel excavation, and more specifically, to a concrete spraying support system that can guide the spray nozzle of a spraying machine to perform automatic construction. [Background technology]

[0002] It is said that roughly two-thirds of Japan's land area is mountainous, and as a result, roads and railway tracks (hereafter referred to as "roads, etc.") almost always have sections that pass through mountainous areas. To build roads, etc. in mountainous areas, it is common to employ either the cut earth method, which excavates part of the slope, or the tunnel method, which hollows out the interior of the natural ground. While the tunnel method tends to have a higher construction cost (construction cost per length of road, etc.) than the cut earth method, it also tends to require less excavated soil (i.e., the amount of soil discharged), and has the advantage of allowing greater freedom in the linear planning of roads, etc. (for example, shortcuts can be taken), and it is said that more than 10,000 tunnels have been constructed in Japan to date.

[0003] Until the 1970s, the mainstream construction method for mountain tunnels was the "sheet pile method," which combined steel arch supports with wooden sheet piles to support the natural ground, but now the New Austrian Tunnelling Method (NATM), which actively utilizes the strength of the natural ground, has become mainstream. NATM's main feature is its design philosophy that relies on the strength of the natural ground (arch effect), which makes it possible to reduce the scale of the tunnel supports compared to the conventional sheet pile method, and also reduces construction costs by improving construction speed.

[0004] Here, we will briefly explain the excavation procedure using NATM. First, the tunnel face is excavated. In the case of blasting excavation, a drill jumbo is used to drill a hole and load explosives (dynamite), and then the workers and the drill jumbo evacuate before blasting. On the other hand, in the case of mechanical excavation, the tunnel face is cut by a free-section excavator. The excavation length (one span length) of one cycle varies depending on the support pattern set according to the strength of the ground, but generally excavation is performed with a span length of 1.0 to 2.0 m. After one span length is excavated, the debris is removed (debris removal) by a dump truck (or rail method) while "scrambling" is performed to remove unstable ground parts (loose stones, etc.). After the debris removal, mirror spraying or primary concrete spraying is performed, and then steel supports are erected as necessary (depending on the support pattern), secondary concrete spraying is performed, and then rock bolts are installed. The primary concrete spraying work, secondary concrete spraying work, and rock bolting work will be carried out on the inner surface of the tunnel (the surface from the side wall to the top) for the length of the excavated span.

[0005] In this way, NATM is a construction method in which excavation is carried out one span (1.0 to 2.0 m) at a time by repeatedly carrying out a series of processes such as rock drilling (for example, drilling holes at the face and blasting), removing debris, erecting steel supports, spraying concrete, and driving rock bolts. Each process in NATM is carried out by an operator operating a dedicated machine.

[0006] For example, concrete spraying work uses a specialized machine called a spraying machine, and the operator sprays the concrete by remotely controlling the spray nozzle at the end of the machine. The "Tunnel Standard Specifications [Mountain Construction Methods]" (Japan Society of Civil Engineers) requires the quality of spraying work as follows: In order to minimize rebound, the spraying nozzle should be kept perpendicular to the surface to be sprayed, and the distance between the nozzle and the surface and the impact speed should be appropriate, and work should be managed to prevent material blockage. Furthermore, it stipulates that the work should be done in a way that eliminates unevenness in the ground, and if there is steel support, care should be taken to ensure that the concrete and the steel support are integrated.

[0007] Proper spraying work requires considerable operating skills, but it is difficult to formulate work procedures or operation manuals, and currently the work relies on the operator's sense based on their experience. On the other hand, the labor shortage in the construction industry has become a serious problem in recent years, and the number of new recruits is decreasing, especially in mountain tunnels, where the inside of the tunnel becomes hot and dusty during excavation. Therefore, the number of skilled operators who perform spraying work will continue to decrease in the future, which is an extremely serious situation for mountain tunnel construction.

[0008] Therefore, there is a strong demand for the establishment of an automated application technique for sprayed concrete, and various application techniques have been proposed. For example, Patent Document 1 focuses on the relationship between the moving speed of the spray nozzle and the thickness of the concrete, and proposes an automated application technique in which the spray nozzle moves at a low speed when spraying onto the excavated ground, and at a high speed when spraying onto the concrete surface. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2019-167678 A Summary of the Invention [Problem to be solved by the invention]

[0010] The technology disclosed in Patent Document 1 is a technology used for automating the spraying work, and aims to smooth the sprayed surface by controlling the moving speed of the spray nozzle. On the other hand, in order to automate the spraying work, it is extremely important to move the spray nozzle on an appropriate trajectory (track) according to the measured face finished shape (amount of overexcavation). In this case, the speed at which the spray nozzle moves is also important, and it is also necessary to pay attention to spraying while overlapping (lapping) between tracks to ensure the designed thickness. However, in the conventional technologies including Patent Document 1, the trajectory of the spray nozzle is not presented in this way.

[0011] The object of the present invention is to solve the problems associated with the prior art, i.e., to provide a concrete spraying support system that can indicate an appropriate trajectory for moving a spray nozzle when automating spraying work. [Means for solving the problem]

[0012] The present invention was made with a focus on calculating the spread area of ​​concrete when it adheres to the sprayed surface, and calculating the trajectory of the spray nozzle based on that spread area, and is an invention based on an unprecedented idea.

[0013] The concrete spraying support system of the present invention is a system that supports concrete spraying performed on a spraying surface (face or excavated ground) in tunnel excavation, and includes a spread area calculation means and a nozzle trajectory setting means. The spread area calculation means is a means for calculating the "spread area" of concrete when it adheres to the spraying surface based on the "spraying distance" from the discharge port of the spraying nozzle to the spraying surface and the "discharge amount" of concrete per unit time. The nozzle trajectory setting means is a means for setting a "nozzle trajectory" that is the path of the spraying nozzle when spraying concrete. The nozzle trajectory setting means sets a plurality of substantially parallel (including parallel) line segments as "individual trajectories", calculates the width of the "strip concrete" formed by spraying concrete along the individual trajectories based on the spread area, and further sets the interval between the individual trajectories based on the width of the strip concrete. When concrete is sprayed along the nozzle trajectory composed of the plurality of individual trajectories, the concrete adheres to the entire spraying surface.

[0014] The concrete spraying support system of the present invention can also be configured to set the intervals between the individual trajectories so that adjacent strips of concrete overlap by a predetermined value.

[0015] The concrete spraying support system of the present invention may further include a speed calculation means. The nozzle speed calculation means is a means for calculating the "movement speed" of the spray nozzle based on the "total spraying time" and the "extension of the nozzle trajectory" required to ensure the "designed sprayed concrete thickness" over the entire range of the sprayed surface. The nozzle speed calculation means calculates the "unit time sprayed concrete thickness" based on the concrete discharge amount per unit time, the rebound rate, and the diffusion area, and calculates the "individual spraying time" required to ensure the designed sprayed concrete thickness based on the unit time sprayed concrete thickness and the design sprayed concrete thickness, and further calculates the total spraying time based on the total area of ​​the sprayed surface, the diffusion area, and the individual spraying time, and then calculates the movement speed of the spray nozzle. In this case, the extension of the nozzle trajectory and the total spraying time are calculated based on the following formula, and the value obtained by dividing the extension of the nozzle trajectory by the total spraying time can be calculated as the movement speed of the spray nozzle. Bn=Qn×(1-R)÷An (Formula 1) Tn=Bd÷Bn (Formula 2) T=α×A÷An×Tn (Formula 3) Qn: Amount of concrete discharged per unit time R: Rebound rate An: diffusion area Bn: Thickness of sprayed concrete per unit time Bd: Design thickness of shotcrete Tn: Individual spray time A: Total area T: Total spray time α: coefficient

[0016] The concrete spraying support system of the present invention may further include an autonomous concrete spraying machine that moves along a nozzle trajectory set by a nozzle trajectory setting means and sprays concrete onto a target surface at a preset amount of concrete discharged per unit time. Effect of the Invention

[0017] The concrete spraying support system of the present invention has the following effects. (1) It is possible to calculate the appropriate trajectory and movement speed of the spray nozzle according to the face shape (amount of overexcavation). This improves the reliability of sprayed concrete construction. (2) Based on the calculated trajectory and movement speed of the spray nozzle, the operation of the boom or arm that controls the spray nozzle can be determined, which means that the spraying work can be automated. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing a situation in which concrete is being sprayed onto a tunnel face using a spraying machine. [Diagram 2] 1 is a block diagram showing the main configuration of a concrete spraying support system according to the present invention. [Diagram 3] FIG. 2 is a side view showing a schematic diagram of the spraying distance from the nozzle outlet of the spray nozzle to the tunnel face. [Figure 4] A model diagram showing the relationship between the flying distance of concrete and its diffusion area. [Diagram 5] FIG. 1 is a front view of a tunnel face, showing a schematic diagram of individual trajectories set with intervals above and below. [Figure 6] (a) is a front view of a tunnel face showing, as a schematic, a situation in which adjacent strips of concrete are formed so that they come into contact with each other above and below, and (b) is a front view of a tunnel face showing, as a schematic, a situation in which adjacent strips of concrete are formed so that they partially overlap (lap) above and below. [Figure 7] FIG. 2 is a flow diagram showing an example of a main process flow of the concrete spraying support system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of the concrete spraying support system of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a situation where concrete is sprayed onto a tunnel face using a spraying machine. The concrete spraying support system of the present invention supports the concrete spraying work by the spraying machine shown in FIG. 1, and one of its technical features is to guide the so-called moving path (hereinafter referred to as the "nozzle trajectory") of the "spraying nozzle" provided at the tip of the spraying machine. Note that concrete spraying work in NATM is performed on "spraying surfaces" such as the unexcavated part of the excavated span (tunnel inner surface) and the tunnel face (mirror surface), but for convenience, an example in which the tunnel face is used as the spraying surface will be described here.

[0020] 2 is a block diagram showing the main components of the concrete spraying support system 100 of the present invention. As shown in this figure, the concrete spraying support system 100 of the present invention is configured to include a calculation processing device 110, and can also be configured to include a concrete spraying machine 120. This calculation processing device 110 is configured to include a diffusion area calculation means 111 and a nozzle trajectory setting means 112, and can also be configured to include a nozzle speed calculation means 113, a measurement means 114, a nozzle control means 115, a measurement data storage means 116, and the like. The concrete spraying machine 120 is configured to include a multi-joint relay mechanism 121 consisting of a boom, an arm, and a hydraulic cylinder, a vehicle body, a traveling means, and the like, in addition to a spraying nozzle 122.

[0021] Among the elements constituting the arithmetic processing device 110, the diffusion area calculation means 111, the nozzle trajectory setting means 112, the nozzle speed calculation means 113, and the nozzle control means 115 can be manufactured as dedicated means, or a general-purpose computer device can be used. That is, the computer device executes arithmetic processing according to a predetermined program, thereby performing processing specific to each means. This computer device is equipped with a processor such as a CPU, memories such as ROM and RAM, input means such as a mouse and a keyboard, and a display, and executes arithmetic processing according to a predetermined program, and can be constituted by a personal computer (PC), a server, a tablet PC such as an iPad (registered trademark), a mobile terminal including a smartphone, or the like.

[0022] The measurement data storage means 116 stores the results of measurements (hereinafter referred to as "measurement data") obtained by the measurement means 114, and can be, for example, a storage device of a personal computer, or can be constructed in a database server. When constructed in a database server, it can be placed in a local network (LAN: Local Area Network), or can be a cloud server that stores data via the Internet.

[0023] Below, each of the main elements constituting the concrete spraying support system 100 of the present invention will be described in detail.

[0024] (Method of measurement) The measuring means 114 is a means for measuring the shape and area (face finished shape) of the tunnel face (sprayed surface) as well as the distance from the discharge port of the spray nozzle 122 to the tunnel face (sprayed surface) as shown in Fig. 3 (hereinafter referred to as "sprayed distance"), and can be mounted on the concrete spraying machine 120. As the measuring means 114, for example, a laser measuring device that performs measurement using a laser sensor, an image acquisition means (such as a camera or video camera) for photo measurement (measurement using a set of two stereo pair images), a total station, etc. can be used.

[0025] The tunnel face finished shape measured by the measuring means 114 is, so to speak, the actual finished shape after excavation (blasting, etc.), that is, it includes "overexcavation". Therefore, the planned finished shape (designed finished shape) and the actual finished shape can be displayed in a superimposed manner, and the amount of overexcavation can be calculated. On the other hand, when acquiring the spraying distance, the spraying distance can be calculated after acquiring the coordinates of the outlet of the spraying nozzle 122 and the tunnel face, respectively, or, if the relative positions (particularly the horizontal distance) of the measuring means 114 and the spraying nozzle 122 are known, the spraying distance can be calculated based on the distance from the measuring means 114 to the tunnel face. Alternatively, the spraying distance can be measured directly by using a tape (measuring means 114). The measurement data (actual finished shape and spraying distance) acquired by the measuring means 114 are stored in the measurement data storage means 116.

[0026] (Diffusion area calculation means) As shown in FIG. 4, the area of ​​concrete discharged from the spray nozzle 122 when it adheres to the tunnel face (hereinafter referred to as the "spread area") is smaller as the flying distance is shorter, and conversely, the longer the flying distance is, the larger the spreading area is, and the diameter related to the spreading area (hereinafter referred to as the "spread diameter") and the flying distance are in a proportional relationship. For example, in FIG. 4, the spreading area An1 related to the flying distance L1 is the smallest, and the spreading area An3 related to the flying distance L3 is the largest, and if the flying distance L3 is three times the flying distance L1, the spreading area An3 is nine times the spreading area An1 (the square of the spreading diameter). On the other hand, since the amount of concrete discharged per unit time (hereinafter referred to as the "unit discharge amount") is usually constant, the shorter the flying distance is, the larger the thickness (hereinafter referred to as the "adhesion thickness") when it adheres to the tunnel face is, and the longer the flying distance is, the smaller the adhesion pressure is. For convenience, the relationship between the flying distance of concrete and the spreading area is referred to as the "distance-area relationship".

[0027] The diffusion area calculation means 111 is a means for calculating the diffusion area. More specifically, the diffusion area calculation means 111 reads out the spraying distance from the measurement data storage means 116, and calculates the diffusion area based on the spraying distance and the distance-area relationship. Incidentally, although the unit discharge amount during the spraying work is constant, the unit discharge amount may be changed depending on the construction site or for each tunnel face. The distance-area relationship differs depending on the unit discharge amount, that is, the scattering angle of the sprayed concrete shown in FIG. 4 differs. Therefore, it is advisable to grasp the distance-area relationship according to the unit discharge amount in advance by carrying out test construction while changing the unit discharge amount. In this way, by using the unit discharge amount and the spraying distance as input values, that is, the diffusion area can be calculated by the distance-area relationship according to the unit discharge amount and the spraying distance.

[0028] (Nozzle trajectory setting means) The nozzle trajectory setting means 112 is a means for setting the “nozzle trajectory (the movement path of the spray nozzle 122).” Below, the procedure by which the nozzle trajectory setting means 112 sets the nozzle trajectory will be described with reference to FIGS.

[0029] First, the nozzle trajectory setting means 112 sets a plurality of line segments that are approximately parallel (including parallel) as "individual trajectories." For example, in Fig. 5, five individual trajectories are set at the tunnel face so that they are approximately horizontal and have intervals above and below. Of course, as long as they can be set so that they are approximately parallel, the individual trajectories can be set in any direction, such as vertical or diagonal, not limited to the horizontal direction.

[0030] The interval between the individual tracks is set based on the diffusion area. When concrete is sprayed along the individual tracks, a strip of concrete (hereinafter, simply referred to as "strip concrete") is formed with a width dimension that is approximately the diffusion diameter (diameter related to the diffusion area). Therefore, the interval between the individual tracks is set according to the width of the strip concrete (i.e., the diffusion diameter). For example, in FIG. 6(a), strips of concrete adjacent to each other are formed to be in contact with each other, and in this case, the interval between the individual tracks is set as the diffusion diameter. On the other hand, in FIG. 6(b), strips of concrete adjacent to each other are formed to be partially overlapped (lapped), and in this case, the interval between the individual tracks is set to a dimension shorter than the diffusion diameter. Although efficient spraying work can be performed by setting the individual tracks as in FIG. 6(a), there is a risk that the reliability of the construction cannot be ensured, such as the occurrence of missed spraying. Therefore, in order to ensure the reliability of the construction, it is better to set the individual tracks as in FIG. 6(b). In addition, the dimension by which the concrete strips are overlapped, i.e., the "lap length" shown in Figure 6(b), can be set in advance as a fixed value (e.g., 3 cm) or according to the width of the concrete strip (e.g., width x 10%).

[0031] When the intervals between the individual trajectories are set, the nozzle trajectory setting means 112 sets a series of nozzle trajectories by connecting a plurality of individual trajectories. Of course, the nozzle trajectory setting means 112 sets the nozzle trajectories so that the shotcrete is applied to the entire tunnel face.

[0032] (Nozzle speed calculation means) The nozzle speed calculation means 113 is a means for determining the movement speed of the spray nozzle (hereinafter referred to as "nozzle movement speed"). Below, the procedure by which the nozzle speed calculation means 113 calculates the nozzle movement speed will be described.

[0033] First, the nozzle speed calculation means 113 calculates the thickness of the sprayed concrete per unit time (hereinafter referred to as "thickness of sprayed concrete per unit time") based on the unit discharge amount (amount of concrete discharged per unit time), rebound rate, and diffusion area. For example, when the unit discharge amount is Qn, the rebound rate is R, and the diffusion area is An, the thickness of the sprayed concrete per unit time Bn can be calculated by "Equation 1". Bn=Qn×(1-R)÷An (Formula 1)

[0034] Next, the nozzle speed calculation means 113 calculates the spraying time (hereinafter referred to as "individual spraying time") required to ensure the designed sprayed concrete thickness based on the unit time sprayed concrete thickness and the planned thickness of the sprayed concrete (hereinafter referred to as "designed sprayed concrete thickness"). For example, if the designed sprayed concrete thickness is Bd, the individual spraying time Tn can be calculated by "Equation 2". Tn=Bd÷Bn (Formula 2)

[0035] Once the individual spraying times are obtained, the nozzle speed calculation means 113 calculates the spraying time (hereinafter referred to as the "total spraying time") required for the sprayed concrete to adhere to the entire tunnel face (sprayed surface) based on the total area and spreading area of ​​the tunnel face (sprayed surface) and the individual spraying times. For example, if the total area is A, the total spraying time T can be calculated using "Equation 3." Note that the coefficient α in Equation 3 is a value that is set according to the "lap length" when strips of concrete overlap, and should be set to a value of 1.0 or less. T=α×A÷An×Tn (Formula 3)

[0036] Once the total spray time is obtained, the nozzle speed calculation means 113 calculates the nozzle movement speed. Specifically, the extension of the nozzle trajectory is obtained, and the nozzle movement speed is divided by the total spray time to calculate the nozzle movement speed.

[0037] (Nozzle control means) The nozzle control means 115 is a means for controlling the automatically operated concrete spraying machine 120 in accordance with the nozzle trajectory and nozzle movement speed output by the arithmetic processing device 110. Specifically, the nozzle control means 115 controls a multi-joint relay mechanism 121 consisting of a boom, an arm, and a hydraulic cylinder so that the spraying nozzle 122 moves at the nozzle movement speed along the nozzle trajectory.

[0038] (Processing flow) Hereinafter, the main processing of the concrete spraying support system 100 of the present invention will be described in detail with reference to Fig. 7. Fig. 7 is a flow diagram showing an example of the flow of main processing of the concrete spraying support system 100 of the present invention, in which the central column shows the processing to be executed, the left column shows information required for that processing, and the right column shows information resulting from that processing.

[0039] As shown in Fig. 7, first, the shape and area of ​​the tunnel face are measured by the measuring means 114, and the spraying distance is also measured (Step 201 in Fig. 7). Once the spraying distance is obtained, the measuring means 114 calculates the diffusion area based on the distance-area relationship according to the unit discharge rate and the spraying distance (Step 202 in Fig. 7).

[0040] When the diffusion area (diffusion diameter) is obtained, the nozzle trajectory setting means 112 sets a plurality of individual trajectories as shown in FIG. 5 (Step 203 in FIG. 7). Note that the individual trajectories at this point are provisional arrangements and are not final arrangements for determining the nozzle trajectory. Next, the interval between the individual trajectories is set based on the diffusion area (diffusion diameter). For example, the interval between the individual trajectories is set so that adjacent strip-shaped concretes on the top and bottom are in contact with each other as shown in FIG. 6(a), or the interval between the individual trajectories is set so that adjacent strip-shaped concretes on the top and bottom are partially overlapped as shown in FIG. 6(b). After the interval between the individual trajectories is set, the arrangement of the individual trajectories is adjusted to the interval (Step 204 in FIG. 7). Then, the nozzle trajectory setting means 112 sets a series of nozzle trajectories by connecting the plurality of individual trajectories.

[0041] Once a series of nozzle trajectories have been set, the nozzle speed calculation means 113 calculates the nozzle movement speed based on the extension of the nozzle trajectory and the total spraying time (Step 205 in FIG. 7). Then, once the nozzle trajectory and nozzle movement speed are obtained, the nozzle control means 115 controls the automatic concrete spraying machine 120 to move the spray nozzle 122 at the nozzle movement speed along the nozzle trajectory (Step 206 in FIG. 7). [Industrial Applicability]

[0042] The concrete spraying support system of the present invention can be used for the first concrete spraying and the second concrete spraying in tunnel excavation. It can also be used for lining concrete for underground cavities such as former air raid shelters and mining sites, or spraying concrete for steep cliffs and slopes to prevent weathering and spalling of rocks, not limited to mountain tunnel construction. The present invention makes it possible to carry out mountain tunnel construction even in the midst of the recent labor shortage, and considering that the construction of construction infrastructure such as roads and railways will continue in the future, it is an invention that can be expected to not only be used industrially but also to make a great contribution to society. [Explanation of symbols]

[0043] 100 Concrete spraying support system of the present invention 110 (Concrete spraying support system) processing unit 111 (Concrete spraying support system) diffusion area calculation method 112 (Concrete spraying support system) nozzle trajectory setting means 113 (Concrete spraying support system) nozzle speed calculation method 114 (Concrete spraying support system) measuring means 115 Nozzle control means (for concrete spraying support system) 116 (Concrete spraying support system) measurement data storage means 120 (Concrete spraying support system) Concrete spraying machine 121 (Concrete spraying machine) multi-joint relay mechanism 122 (Concrete spraying machine) spray nozzle

Claims

1. A system for supporting concrete spraying performed on a spraying surface such as a face or an excavated ground in tunnel excavation, a diffusion area calculation means for calculating a diffusion area of ​​the concrete when the concrete adheres to the sprayed surface based on a spray distance from a discharge port of the spray nozzle to the sprayed surface and an amount of concrete discharged per unit time; a nozzle trajectory setting means for setting a nozzle trajectory which is a path of the spray nozzle when spraying concrete, the nozzle trajectory setting means sets a plurality of parallel or approximately parallel line segments as individual trajectories, calculates a width of a strip-shaped concrete formed by spraying concrete along the individual trajectories based on the diffusion area, and sets an interval between the individual trajectories based on the width of the strip-shaped concrete; When concrete is sprayed along the nozzle trajectory composed of the plurality of individual trajectories, concrete adheres to the entire sprayed surface. A concrete spraying support system.

2. The nozzle trajectory setting means sets the intervals between the individual trajectories so that adjacent strips of concrete overlap each other by a predetermined value.

2. The concrete spraying support system according to claim 1 .

3. Further provided is a nozzle speed calculation means for calculating a moving speed of the spray nozzle based on a total spray time required to ensure a designed spray concrete thickness over the entire range of the spray surface and an extension of the nozzle trajectory, the nozzle speed calculation means calculates a unit time thickness of sprayed concrete based on the amount of concrete discharged per unit time, the rebound rate, and the diffusion area, and calculates an individual spraying time required to ensure the design sprayed concrete thickness based on the unit time thickness of sprayed concrete and the design sprayed concrete thickness, and further calculates the total spraying time based on the total area of ​​the sprayed surface, the diffusion area, and the individual spraying times, and then calculates the moving speed of the spray nozzle; 2. The concrete spraying support system according to claim 1 .

4. The nozzle speed calculation means calculates the thickness Bn of the sprayed concrete per unit time by (Equation 1) using the amount Qn of concrete discharged per unit time, the rebound rate R, and the diffusion area An, Bn=Qn×(1-R)÷An (Formula 1) The nozzle speed calculation means calculates the individual spraying time Tn by (Equation 2) using the unit time sprayed concrete thickness Bn and the design sprayed concrete thickness Bd, Tn=Bd÷Bn (Formula 2) Furthermore, the nozzle speed calculation means calculates the total spraying time T by (Equation 3) using the total area A of the spray surface, the diffusion area An, the individual spraying time Tn, and a coefficient α, T=α×A÷An×Tn (Formula 3) The extension of the nozzle trajectory divided by the total spray time T is set as the movement speed of the spray nozzle.

4. The concrete spraying support system according to claim 3.

5. It is also equipped with an autonomous concrete spraying machine. the concrete spraying machine sprays concrete onto the spraying surface at a preset discharge amount of concrete per unit time while the spraying nozzle moves along the nozzle trajectory set by the nozzle trajectory setting means; 2. The concrete spraying support system according to claim 1 .

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