JP3922440B2 - Steel frame dam - Google Patents

Description

[0001]
[Technical field belonging to the invention]
The present invention relates to a steel frame dam such as a sabo dam which is suitable for application when there is a possibility that the downstream surface of the steel frame may be damaged due to the flow of a debris flow.
[0002]
[Prior art]
Conventionally, a cubic lattice-shaped steel frame assembled by connecting a large number of column members, horizontal materials in the left-right direction and depth materials in the front-rear direction by bolt joints, and a screen material on the front and rear surfaces of the steel frame Installation and filling of the inside filling material to construct a steel frame dam such as a sabo dam.
[0003]
Steel frame dams are superior to concrete structure dams in that they are easy to construct, have a shorter construction period, are less expensive to construct, and are water permeable. In addition, because it is a structure that consists of subdivided members connected with bolts, it is a place that requires urgency, a place that is difficult to transport concrete, a place with poor ground conditions, a place that can only be installed with a steel frame structure such as a landslide belt It is ideal for building a sabo dam.
Some conventional steel frame dams of this type protect the upstream surface from impacts such as debris flow by providing a buffer wall on the upstream surface of the steel frame (see JP 2000-144692 A). The downstream surface side is not particularly considered, and the column surface, the horizontal material, and a large number of screen materials simply face the downstream surface.
[0004]
[Problems to be solved by the invention]
The conventional steel frame dam can prevent damage to the upstream surface of the steel frame due to the impact of the debris flow at the buffer wall on the upstream surface. However, when the debris flow exceeds the dam, when the debris flow flows down the inclined downstream surface of the dam, the flowing debris flow may damage the downstream surface of the steel frame. In particular, when the screen material is sideways, it is easily damaged by the flowing debris flow, and in that case, the filling material may flow out.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a steel frame dam such as a sabo dam that does not cause the downstream surface of the steel frame to be damaged by the debris flow.
[0006]
[Means for Solving the Problems]
The present invention that solves the above-mentioned problem is that a plurality of pillar materials, a horizontal material in the left-right direction, and a depth material in the front-rear direction are connected by bolt joining, and a plurality of steel frames are formed on at least the front and rear surfaces. A steel frame dam constructed with screen materials attached at intervals and filled with filling material inside,
A number of protective materials made of steel bars are vertically mounted on the downstream surface of the steel frame with left and right intervals, and the upper end portion of the protective material is fixed to the top-end protective concrete and the lower end portion is fixed to the hammered concrete. It is characterized by.
[0007]
According to a second aspect of the present invention, in the steel frame dam according to the first aspect, the screen material is mounted horizontally with a vertical space between the left and right column members.
[0008]
According to a third aspect of the present invention, in the steel frame dam according to the first or second aspect, the H-shaped steel is used as a protective material, the flange surface is directed in the front-rear direction, and the inner flange portion is bolted to the horizontal material or the screen material. It is characterized by being attached with.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied as a sabo dam installed in an upstream area of a river will be described with reference to FIGS.
FIG. 1 is a schematic cross-sectional view (on the right side is upstream) of a sabo dam 11 constructed by applying the present invention. FIG. 6 is a perspective view schematically showing a steel frame 13 constituting the sabo dam 11, and FIG. 5 is a perspective view showing a detailed structure of one box frame 6 constituting the steel frame 13.
As shown in these drawings, the steel frame 13 connects the upper and lower portions of the column members 1 and 2 made of, for example, H-shaped steel provided in the front and back, respectively, with a depth material 3 made of, for example, groove-shaped steel. The upper and lower portions of the column members 1, 1 (or 2, 2) are connected by a horizontal member 5 made of, for example, grooved steel, and the upper and lower portions of the column members 1, 2 are, for example, grooved steel or angle steel. As shown in FIG. 6, the box frame 6 is continuously formed in the left, right, front, back, top and bottom and assembled as necessary. Then, a plurality of screen materials 9 are mounted horizontally with vertical spacing between the left and right column members 1, 1 (or 2, 2) on at least the front and rear surfaces of the steel frame 13, and the steel is formed at an appropriate stage. The sabo dam 11 is constructed by filling the inside of the frame 13 with a filling material and providing a lid screen material (not shown) on the uppermost upper surface. In addition, although the detail of the connection structure of each member is abbreviate | omitted, all are bolt joining (joining by a volt | bolt nut). Moreover, the screen material 9 shown in the figure is a lightweight grooved steel, and is fixed to the inner side surfaces of the outer flanges of the column members 1 and 2 that are H-shaped steel with bolts and nuts.
[0010]
In the present invention, on the downstream surface of the steel frame 13 (the surface on the left side of FIGS. 1 and 2 (a)), for example, a large number of protective members 15 made of H-shaped steel are attached vertically with a space left and right, The upper end portion of the protective material 15 is fixed to the top end protective concrete 16, and the lower end portion is fixed to the water hitting concrete 17.
The protective material 15 is divided into protective material pieces 15 ′ having the same length as the pillar material 1 of each box frame 6, and as shown in detail in FIGS. 15 'are in contact with each other, and the joint plate 20 applied to the H-shaped web surface is fastened with bolts and nuts to be connected to each other to form one continuous protective material 15 from the upper end to the lower end.
Further, in the illustrated example, each protective material piece 15 ′ is attached in a state where the H-shaped inner flange portion 15a is applied to the horizontal material 5 and the screen material 9, but in the illustrated example, the inner flange portion 15a is horizontally disposed. The material 5 and the three screen materials 9 are fixed with bolts 22 and nuts 23 via a taper washer 21. Although it is appropriate that the length of the protective material piece 15 ′ constituting the protective material 15 is the same as that of the pillar material 1 as in the embodiment, it is not necessarily the same.
In addition, a concrete wall 25 is formed in the inner portion of the screen material 9 at the lowermost portion of the downstream surface of the steel frame 13.
Note that the column members 1 adjacent to each other in the vertical direction are connected to each other by fastening a joint plate 26 (see FIG. 4A), which is in contact with an H-shaped outer flange surface, with a bolt and a nut.
[0011]
In the above-mentioned sabo dam 11, when a debris flow including gravel and driftwood occurs on the upstream side and exceeds the sabo dam, the debris flow (including gravel and driftwood) flows down the downstream surface of the steel frame 13, but the debris flow Flows down along the vertical protective material 15 arranged on the downstream surface of the steel frame 13 and does not hit the horizontal screen material 9 and the horizontal material 5 inside thereof. That is, the screen material 9 and the horizontal material 5 are protected by the protective material 15 and are prevented from being worn or damaged by the flowing debris flow.
Further, a downward impact load due to the debris flow acts on the protective material 15 to which the flowing debris flow hits. However, since the lower end portion of the protective material 15 is fixed to the water-splashing concrete 17, the shock load passes through the water-spreading concrete 17. It is transmitted to the ground and not transmitted to the steel frame 13. Therefore, there is no possibility of damaging the connecting portion of each member of the steel frame 13.
Also,
Further, the protective material 15 is H-shaped steel, and the inner flange portion is attached to the horizontal material 5 and the screen material 9 with bolts, so that the bolt mounting portion is protected by the outer flange portion of the H-shaped steel, There is little risk of debris flow and direct damage.
[0012]
In addition, the space | interval of the left-right direction of the protective material 15 is good to set to an appropriate space | interval according to the debris flow which may flow down.
In the embodiment, each protective material piece 15 ′ constituting the protective material 15 is attached to four locations of the horizontal material 5 and the three screen materials 9, but the horizontal material 5 and four or more or two or less screens. It may be attached to the material 9, or may be attached to only one or a plurality of screen materials 9 or only to the horizontal material 5.
When the screen material 9 is horizontal, it is easily damaged by the debris flow that flows down. Therefore, the present invention is preferably applied, but the present invention can also be applied when the screen material is vertical.
Although the H-shaped steel is suitable for the protective material 15, a grooved steel or other strip steel may be used.
The present invention is suitable for application to a sabo dam, but is not limited to this, and can also be applied to a normal dam.
[0013]
【The invention's effect】
According to the steel frame dam of the present invention, on the downstream surface of the steel frame, a large number of protective materials such as H-shaped steel are vertically attached with a space left and right, and the upper end portion of the protective material is a top-end protective concrete. In addition, since the lower end portion is fixed to the water hitting concrete, the following effects are obtained.
(1) Even if the debris flow crosses the steel frame dam and flows down the downstream surface, the debris flow will flow along the vertical protective material, and the screen material and horizontal material inside it will be protected and damaged by the protective material. There is no fear.
(2) Since the lower end portion of the protective material is fixed to the hammered concrete, the downward impact load due to the debris flow acting on the protective material is transmitted to the ground through the hammered concrete and not to the steel frame. Therefore, there is no possibility of damaging the connecting portion of each member of the steel frame.
(3) According to claim 3, the bolt mounting portion of the protective material to the steel frame is hidden inside the outer flange portion of the protective material which is H-shaped steel, so that the debris flow directly collides with the bolt mounting portion. There is little fear, and the bolt mounting part of the protective material itself can be prevented from being damaged by the debris flow.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a steel frame dam according to an embodiment of the present invention.
2A is an enlarged view of a downstream portion of FIG. 1, and FIG. 2B is a left side view of FIG.
FIG. 3 is a detailed enlarged view of a part A in FIG. 2;
4A is a left side view of FIG. 3, and FIG. 4B is a plan view of FIG.
FIG. 5 is a perspective view of one box frame at the uppermost stage of the steel frame in the steel frame dam.
FIG. 6 is a perspective view schematically showing a steel frame in the steel frame dam.
[Explanation of symbols]
1 and 2 Column material 3 Depth beam 5 Horizontal material 6 Box frame 7 Brace 9 Screen material 11 Sabo dam (steel frame dam)
13 Steel frame 15 Protective material 15 ′ Protective material piece 16 Top end protection concrete 17 Water hammering concrete 20 Joint plate 21 Taper washer 22 Bolt

Claims (3)

A plurality of screen materials are attached at intervals to at least the front and rear surfaces of a cubic lattice-shaped steel frame assembled by connecting a large number of pillar materials, horizontal materials in the left-right direction and depth materials in the front-rear direction by bolt joining, It is a steel frame dam constructed by filling the filling material inside,
A number of protective materials made of steel bars are vertically mounted on the downstream surface of the steel frame with left and right intervals, and the upper end portion of the protective material is fixed to the top-end protective concrete and the lower end portion is fixed to the hammered concrete. A steel frame dam characterized by 2. The steel frame dam according to claim 1, wherein the screen material is attached horizontally with a vertical space between left and right column members. 3. The steel according to claim 1, wherein an H-shaped steel is used as the protective material, the flange surface thereof is directed in the front-rear direction, and an inner flange portion is attached to the horizontal material or screen material with bolts. A frame dam.

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