JPH0512344Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is based on an erosion control dam using a steel arched lattice.
In particular, the present invention relates to sabo dams that regulate debris flows in mountain streams and streams in mountainous areas, have excellent structural safety and ease of construction, and do not deteriorate in function over a long period of time.

(Prior Art) Currently used debris flow control means include concrete sabo dams, which are installed in valleys where debris flows frequently occur or are expected to occur. As is well known, concrete erosion control dams, which have been widely used in the past, have a concrete wall extending over the entire surface so as to cross the flow of debris flow. However, although this concrete dam construction method has the advantage of completely controlling small gravel and muddy water contained in debris flows, depending on the scale of the debris flow, it can become full of sand after just one or two debris flows.
There are many problems such as the fact that it quickly loses its function as an erosion control dam, the large-scale structure that absorbs the huge energy of the debris flow, and the construction cost being enormous because it is on-site construction in a mountainous area. It has its drawbacks.

Therefore, in recent years, a slit-type erosion control dam has been proposed and implemented, which has a type of screen effect by restricting only large gravel among the debris flowing down, while allowing small gravel and muddy water to pass downstream. No. 51-58536, Japanese Patent Publication No. 57-29717). or,
A slit-type sabo dam that forms a three-dimensional frame like the Young Gym has also been proposed (Japanese Patent Application Laid-Open No. 1989-1999).
−115520).

Figure 4 shows a conventional slit-type sabo dam; Figure 4a shows a side view of a concrete dam, Figure 4b shows a side view of a slit-type sabo dam using steel pipes, and Figure 4c shows its plan view. The figure is shown below.

In FIG. 4a, the dam body 40 is provided with comb-shaped slits 42 made of concrete. In addition, in FIGS. 4b and 4c, a triangular frame 45 is constructed of steel pipes 44, and although it is not clearly shown in the drawing, a plurality of these frames are arranged to construct a slit type sabo dam. It consists of
In this case, it is necessary to use a large steel pipe in terms of strength.

However, even though the slit type dam as mentioned above can be expected to have a clean effect at first, when large gravel is restricted by the dam due to a debris flow, it becomes clogged and the slit gaps disappear.
No screen effect can be expected from subsequent debris flows, and the structure will be similar to that of conventional concrete dams, which will eventually become filled with debris and lose its functionality.

(Problems to be solved by the invention) The purpose of the invention is to solve the above-mentioned problems of the conventional technology, to exhibit a screen effect as an erosion control function for a longer period of time, and to have excellent structural safety and workability. The purpose of this project is to provide a sabo dam.

(Means for solving the problem) Here, the present invention provides a plurality of horizontal arch members made of steel in the vertical direction, connects each arch member in the vertical direction with a connecting member, and connects each arch member in the vertical direction. A structure in which the lattice spacing formed by the timber and the connecting material is set to a sufficient interval to prevent boulders in a debris flow,
This is an erosion control dam made of a steel arch-shaped lattice, characterized in that the ends of the arch members are fixed to the battlements so that the convex portions of the arch members are located upstream in the flow direction of the river.

In a preferred embodiment of the present invention, a required number of steel frames made of a combination of vertical members and diagonal members are attached to the erosion control dam in a discrete manner in the arch span direction on the downstream side of the arch members, thereby increasing the strength. further reinforced.

Note that the arch material may be made of a short-span steel pipe, and furthermore, the parapet wall may be made of concrete and the other members may be made of reinforcing concrete-filled steel pipes.

In this way, according to the present invention, by adopting a steel arch-shaped lattice instead of the conventional slit-type dam or three-dimensional frame structure, small gravel,
It becomes possible to flow muddy water from the arch section. In addition, by using an arch shape on the front surface, boulders can easily move to the battlements, and the convex part of the arch allows small gravel to be removed.
Since the flow of muddy water is not obstructed, the screen effect as an erosion control function can be exhibited for a longer period of time.

Furthermore, as mentioned above, by constructing the steel arch material from several single-span steel pipe members, it is not only easy to transport to the site and assemble on site, but also to be easily damaged by debris after use. It becomes possible to easily replace the steel pipe member at the location where it has been removed.

In addition, when the arch material is composed of pipe materials,
The inside of the pipe may be filled with concrete or the like to form a solid body. The parapets supporting such an arch on both sides are preferably made of reinforced concrete.

The applicant of this invention previously proposed a slit-type sabo dam using arch-type lattice in Japanese Patent Application No. 251657/1987, but this was a system in which the ends of the steel arch material were fixed to the tie material and main columns, allowing the frame system to withstand the impact force of a debris flow alone, and although the steel arch-type lattice alone was compact, it was necessary to arrange it in multiple rows. The sabo dam of this invention is an improvement that eliminates the tie material and main columns of the steel arch-type lattice and fixes the ends to a concrete breast wall, making it larger and simpler, increasing its strength, and eliminating the multiple-row arrangement, making it able to withstand debris flows as a single unit.

Furthermore, with the above improvements, by moving boulders only to both sides of the channel and limiting the debris flow to the center of the channel, the ability to flow small debris is improved, and it is possible to prevent debris flows from occurring again on both banks. This is an improvement to protect the fixed part.

(Operation) Next, the present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 is a perspective view schematically showing an example of an erosion control method in which a steel arched lattice structure is applied to a river. The illustrated structure is further shown in plan view in FIG.
As shown in the front view in b and in the side view in c, several horizontal arch members 1 and connecting members 2,
It is composed of a parapet wall 4 and a steel arch lattice 3. The ends of the steel arch lattice 3 are fixed and supported by parapets 4, preferably made of concrete. In addition, the legs of the connecting member 2 are
It is embedded into the lower concrete floor 6 by the required length. Therefore, the steel arch lattice 3 is fixed on three sides and has a fairly strong structure in terms of strength. In the illustrated example, a lower concrete floor is formed as the foundation part of the erosion control dam according to the present invention, but this is not necessarily essential. In some cases, it may be sufficient to simply bury it in the ground.

The members constituting such a structure may be joined by welding or bolts. Each arch material 1
The lattice spacing formed by the connecting members 2 and 2 is set to a spacing that prevents boulders from debris flow, and the convex portion of the arch material is placed upstream in the flow direction of the river. The arch material 1 is basically formed of a steel pipe with a closed cross section,
The steel pipe may contain reinforcing bars and be filled with concrete. In that case, the strength of the arch portion will be sufficient to withstand the impact of the boulders.

In order to further increase the strength of the arch, the third
As shown in Figures a, b, c, d and e, the required number of approximately triangular steel frames 5, each consisting of a combination of vertical members 7, diagonal members 8 and horizontal members 9, are arranged discretely in the arch span direction. It is also possible to attach it to the arch material. Regarding the attachment of the steel frame 5 to the arch material, it is preferable to provide the steel frame 5 over the center of the arch lattice in order to increase resistance to impacts from boulders and the like. The legs of the diagonal member 8 are embedded and fixed in the lower concrete floor similarly to the connecting member 2.

Figure 3a is a plan view of the erosion control dam when the steel frame 5 is attached to the arch lattice 3;
and c are lines AA and B in Figure 3a, respectively.
- Fig. 3 is a cross-sectional view taken along line B, d is a schematic plan view of the sabo dam when two steel frames 5 are provided, and e is a schematic plan view showing the structure of only the steel frame 5. FIG.

FIG. 5 is a schematic explanatory diagram showing the behavior of boulders that collided with the arch part of the above structure, and as shown in the figure,
Since this structure has an arch shape, the boulders 10 and the like can easily move toward the parapet wall section indicated by reference numeral 4, and their capture position can always be at the end of the arch lattice. Therefore, small gravel and muddy water can flow through the grid in the center of the arch. The so-called screen effect is exhibited over a long period of time. Moreover, even if this arch lattice part is located in the center, the arch material 1, the connecting material 2,
Further, it is reinforced as required by various actions of the steel frame 5, and can sufficiently withstand the impact of ordinary boulders.

In addition, as shown in Fig. 6, steel arch materials are
It is composed of several short-span steel pipe members 11, each of which may be bolted together using a flange joint 12. Therefore, when such a short span steel pipe is used, it is not only easy to transport to the site and assemble at the site, but also to easily replace damaged parts after use.

From the above description, the details of assembly will be obvious to those skilled in the art, and therefore further explanation will be omitted.

(Effects of the invention) As described above, the present invention is configured to capture only large gravels in a debris flow, allow small gravels and muddy water to pass through, and collect the captured gravels on the parapet, and has the following effects: has.

(1) Only large stones are restricted, and the screen effect is fully demonstrated.Since the structure is made of an arched lattice, boulders are moved to the battlements, and small stones and
It is possible to flush muddy water, and it can provide a long-term screen effect, or erosion control ability, compared to conventional construction methods.

(2) By using a steel arched lattice, it is strong, and by reinforcing it with a steel frame, it is possible to provide a structure with high strength and toughness, so it will not be breached by debris flows. .

(3) When steel arch materials are constructed from short-span steel pipe members, it is easier to transport and assemble on-site, and it is also possible to replace parts damaged by gravel. Workability, maintenance,
Excellent repair performance.

[Brief explanation of the drawing]

Figure 1 is a schematic perspective view of the steel arch lattice sabo dam according to the present invention applied to a river; Figure 2a is a plan view, and Figure 2b is a front view;
Figure 3 (c) is a side view; Figure 3 (a) is a plan view of the sabo dam with a steel frame attached, Figure 3 (b), and Figure 3 (c).
are a cross-sectional view taken along lines A-A and B-B in Fig. 3a, d is a schematic plan view of the sabo dam when two steel frames 5 are installed, and e is
is a schematic side view of only the steel frame 5; FIG.
Each shows a conventional slit-type erosion control dam, where a is a side view of a concrete dam, and b is a side view of a concrete dam.
is a side view of a slit-type sabo dam using steel pipes,
Figure 5 is a schematic explanatory diagram showing the behavior of boulders that collided with the arch of the structure;
and FIG. 6 is a schematic perspective view showing how a steel arch material made of short-span steel pipe members is assembled. 1... Arch material, 2... Connecting material, 3... Steel arch lattice, 4... Concrete parapet, 5... Steel frame.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A plurality of horizontal steel arch members are provided in the vertical direction, each arch member is vertically connected by a connecting member, and each arch member and the connecting member are connected in the vertical direction. The end of the arch material is connected to the parapet so that the convex part of the arch material is located upstream in the flow direction of the river. An erosion control dam made of a steel arch-shaped lattice, which is characterized by being fixed to a steel arch-shaped lattice. (2) The erosion control dam according to claim (1), wherein a required number of steel frames made of a combination of vertical members and diagonal members are installed discretely in the arch span direction on the downstream side of the arch members.