JPH058320B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a nozzle used in the shotcrete method for spraying concrete onto tunnel walls, etc., and applies quick-setting concrete uniformly over the entire thickness of the primary lining. This invention relates to a concrete spraying nozzle for forming a primary lining that has no cavities and is excellent in strength by spraying concrete.

(Conventional technology) The shotcrete method is a construction method that can be constructed to suit the shape of a fairly wide area without the need for formwork, and conventionally there are dry, wet, and semi-wet methods for this construction method. Generally adopted.
Each of the above three methods has advantages, but all have the disadvantage of generating a large amount of dust and splashing. Various new materials and new construction methods using these new materials are being developed to eliminate these drawbacks. However, although new materials and construction methods have reduced the amount of dust and splashes,
Complete resolution has not yet been reached.

In view of the above-mentioned circumstances, the applicant of the present invention previously proposed a lining method and apparatus as disclosed in Japanese Patent Application Laid-Open No. 61-53999.

In this direction, as shown in FIG. 4, a formwork 8 having an endless belt 7 wound around a large number of rollers 6 is placed facing the tunnel wall with a predetermined gap, and the belt type formwork 8 is Rapidly setting concrete 11 is supplied from the installed nozzle 10 to the gap between the belt type formwork 8 and the tunnel wall surface 9 and placed, and the poured concrete 12 is poured into the tunnel wall surface 9 by the belt type formwork 8. The primary lining is constructed while the belt-type formwork 8 is raised at a speed corresponding to the hardening time of the concrete 12 while being pressed in the direction, and is a new construction method that does not generate dust or splashing.

(Problem to be solved by the invention) Nozzle 10 used in the above construction method
is an extremely common type in which the exit part is simply cylindrical, and if the tunnel wall surface 9 is in good condition and the primary lining thickness is relatively thin (6 to 10 cm), the nozzle It is possible to pour and fill the gap with the quick-setting concrete 11 that is sprayed in a conical shape from the concrete 10 without any trouble.

However, the condition of the tunnel wall surface 9 is poor,
When there is a lot of excess digging or when the primary lining is thick (10
~30cm or more), use nozzle 10 as described above.
In this case, there was a problem in that the sprayed quick-setting concrete 12 did not spread throughout the void, resulting in the formation of a cavity 13.

This invention was made to solve the above-mentioned problems of the conventional ones, and its purpose is to spray and supply concrete to the entire predetermined gap, regardless of the condition of the tunnel wall surface or the thickness of the lining. To provide a concrete spraying nozzle that can provide a concrete wall lining of good quality.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a plurality of inclinations at different angles in the direction of blocking the flow of concrete on a part of the periphery of the spray nozzle of the spray nozzle body. This concrete spraying nozzle is characterized by being provided with inclined plates and having an opening that is not obstructed by the inclined plates.

(Operation) Concrete sprayed from the spray nozzle body collides with multiple inclined plates installed at different angles of inclination in the direction that blocks the flow, and is sprayed along them in different angular directions. On the other hand, the concrete is sprayed in a straight line in the same direction as the axial direction of the spray nozzle body from the opening that is not obstructed by these, and in this way, the concrete is sprayed onto the tunnel wall surface with a wide range of angular spread. As a result, the water is supplied throughout the predetermined gap on the tunnel wall surface, and no cavities are created in the concrete lining wall.

(Embodiment) Figures 1 and 2 show an embodiment of the present invention, in which a concrete spraying nozzle, generally designated by the reference numeral 1, has a prismatic spraying nozzle body 2, and a part of the outlet peripheral edge 2a thereof is The side plate extends at the portion to form an extending portion 3. The extension part 3 has two inclined plates 4 and 5.
is fixed, and a slit-shaped opening 6 is formed between both inclined plates 4 and 5. Both inclined plates 4 and 5 are inclined in a direction that blocks the flow of concrete, and the inclined angle α of one inclined plate 4 is larger than the inclined angle β of the other inclined plate 5.

With the above configuration, the spray nozzle body 2
The flow of concrete sprayed by air from the opening 6 is in a straight line direction similar to the direction of the spray nozzle body 2 shown by arrow A, and in a small direction shown by arrow B after colliding with the inclined plate 5 and along it. Incline angle β
and the direction of the large inclination angle α shown by arrow C, which collides with the inclined plate 4 and follows it, respectively, and the spray direction expands angularly and becomes fan-shaped, hitting the tunnel wall surface. It is sprayed and evenly distributed and filled throughout the predetermined voids in the tunnel wall. When primary lining is performed using such a concrete spraying nozzle 1 as shown in FIG. The filling is evenly distributed and filled throughout the gap between the tunnel wall surface 9, and no cavities are generated as in the conventional case. Furthermore, even when a reinforcing wire mesh 14 or the like is installed inside the primary lining concrete wall, the directionality of the flow makes it easier for concrete to pass through the mesh, so the amount of concrete that hits the wire mesh 14 and bounces back is extremely small. Almost no support.

The inclination angles α and β of the inclined plates 4 and 5 are determined depending on the lining thickness or the unevenness of the tunnel wall surface, such as α = 40° and β = 30° when the lining thickness is 10 to 15 cm, for example. Various changes are made. It is desirable that the size of the opening 6 is slightly smaller than the maximum coarse aggregate size in the concrete.

Although there are two inclined plates in this example,
The number of openings is not limited to this, and the number of openings may be three or more, and the opening may have various shapes such as circular or square instead of a slit. The nozzle of the present invention can be applied not only to the tunnel lining method described above, but also to general concrete spraying methods.

(Effects of the Invention) As described above, this invention provides a plurality of inclined plates that are inclined at different angles in the direction of blocking the flow of concrete on a part of the periphery of the spray port of the spray nozzle body, and Since an unobstructed opening is formed by the inclined plate, the concrete sprayed from the spray port of the spray nozzle body is
Through the opening, the spraying direction is directed in a straight line similar to the direction of the spray nozzle body, and in directions of different angles of inclination, colliding with a plurality of inclined plates and along them, so that the spraying direction expands angularly. It is sprayed onto the tunnel wall in a fan shape, and is evenly distributed and filled into the entire predetermined gap on the tunnel wall, regardless of the condition of the tunnel wall surface or the thickness of the lining. Unlike conventional nozzles, no cavities are created, and the effect is that high-quality concrete walls can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the nozzle according to the present invention, FIG. 2 is a right side view of the same, and FIG.
The figure is a vertical cross-sectional view showing the usage condition of the same as above.
The figure is a longitudinal cross-sectional view showing the state of use of a conventional device. 1... Nozzle, 2... Nozzle body, 4, 5...
Inclined plate, 6...Opening, 9...Tunnel wall surface, 11
... Rapid setting concrete, 13 ... Cavity part.

Claims (1)

[Claims] 1 Part of the periphery of the spray nozzle body,
A concrete spraying nozzle characterized in that a plurality of inclined plates are provided that are inclined at different angles in a direction that blocks the flow of concrete, and an opening that is not blocked by these inclined plates is formed.