JP2003193451A - Permeable check dam and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permeable check dam and a manufacturing method therefor, which can inhibit the downstream flow of earth and rocks only in an abnormal deluge while maintaining prescribed strength or above, and which enable the provision of an optimal sediment trapping function based on a condition of sedimentation upstream from the permeable check dam without causing a decrease in strength. <P>SOLUTION: This permeable check dam permits the running earth and rocks to flow downstream in an ordinary deluge, and inhibits the running earth and rocks from flowing downstream in the abnormal deluge. The check dam has: a concrete structure 2 which is equipped with slits 3 for making the earth and the rocks permeate to a downstream side, and laid so as to block the downstream flow of the earth and the rock; cylindrical bodies 5 which are provided in the slits 3 so as to make the upstream side of the concrete structure 2 communicate with the downstream side thereof, and whose bores are set to be equivalent to a maximum gravel diameter of the earth and the rocks, running in the ordinary deluge; and filling concrete parts 4 which are formed by filling the insides of the slits 3 with concrete. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permeation type erosion control dam which permits the flow of debris that flows during normal flooding and prohibits the flow of debris that flows during abnormal flooding.

[0002]

2. Description of the Related Art In the past, when a debris flow was generated, an impermeable erosion control weir, which blocks all the debris flow regardless of its scale, was the mainstream. However, in recent years, impermeable sabo dams cause problems such as riverbed deterioration and coastline receding due to the lack of sediment supply in the downstream region, so the debris flow is dammed only during abnormal floods, and normally the sediment is blocked. Attention has been paid to a slit-type transmission type erosion control dam that can flow down to the downstream, that is, a transmission type erosion control dam having a slit opened in the vertical direction with a constant width.

[0003]

[Problems to be Solved by the Invention] However, in the past,
When constructing such a slit type transmission type erosion control weir with a predetermined strength or more, a portion having a small cross-sectional area is formed due to the provision of the slit, which causes a strength problem in the transmission type dam. . Therefore, there is a problem that the width and the number of slits are limited in order to maintain the strength of the dam more than a predetermined level.

Further, in the debris flow at the time of abnormal flooding, there are many heavy and large gravel diameters near the bottom of the water, and small gravel diameters and small weights near the water surface. Therefore, in order to enhance the ability to capture debris in the event of an abnormal flood, it is expected that a large diameter debris will be captured in the lower part of the permeable sabo dam and a smaller diameter in the upper part. However, like the slit type transmission type erosion control dam shown above, if the slits are opened with a certain width in the vertical direction, the debris trapping capacity will be the same from the upper part to the lower part of the slit. There is a problem that it is not possible to have an optimal sediment trapping function according to the condition of sedimentation upstream of the Sabo dam. It should be noted that it is possible to increase the width of the slit from the upper part to the lower part in order to cope with the condition of sedimentation upstream of the transparent erosion control dam, but in this case,
The problem that the strength of the dam is reduced becomes remarkable.

The present invention has been made in view of the above-mentioned problems, and provides a permeable erosion control dam and a method of manufacturing the same, which can inhibit the flow of debris only during abnormal flooding while maintaining a strength not lower than a predetermined level. This is the first purpose. Further, it is a second object of the present invention to provide a permeable sabo dam and a method for producing the same, which can have an optimal sediment trapping function according to the sedimentation condition upstream of the permeable sabo dam without lowering the strength. To do.

[0006]

In order to solve the above-mentioned problems, the permeable erosion control weir proposal according to claim 1 of the present invention permits the flow of flowing debris during normal flooding, and during abnormal flooding. Is a transmission-type sabo dam that prohibits the flow of flowing debris, has a slit that allows the debris to permeate downstream, and a concrete structure laid so as to block the debris flow, and the upstream side of the concrete structure. And provided in the slit so as to communicate with the downstream side,
It is characterized in that it has a first tubular body set to a diameter of the maximum gravel diameter of the earth and stone that flows at the time of the normal flooding, and a filling concrete portion formed by filling concrete into the slit.

According to the above construction, since the gap between the slit and the first cylindrical body is closed by the filling concrete portion, the entire dam is integrated, so that the slit has a large width. Even when it is formed with or when a lot of slits are formed, it is possible to maintain the high strength of the transmission-type erosion control dam. Therefore, by setting the diameter of the first tubular body to the maximum gravel diameter of the debris that flows during normal flooding, even if the slit in which the first tubular body is provided has a large width, Can be provided with a predetermined strength or more. Thus, the permeable erosion control weir basin having a strength of a predetermined level or more can flow debris of all sizes from the first tubular body during normal flooding, while abnormal flooding causes the size of the gravel to exceed the maximum gravel diameter. When a large-sized debris flows, it is possible to prohibit the debris of this size from flowing down by the first tubular body. Therefore, the flowing-down can be prohibited only at the time of abnormal flooding.

According to a second aspect of the transmission type erosion control dam, in the first aspect, the first tubular body is arranged in a lower region of the slit, and in the upper region of the slit above the first tubular body. Is characterized in that a second tubular body having a smaller diameter than the first tubular body is provided.

According to the above construction, the debris flowing below the debris flow and having the maximum gravel diameter or more is prohibited by the first tubular body, and the debris or driftwood flowing above the debris flow and having a diameter smaller than the maximum gravel diameter is The second tubular body is prohibited from flowing down. As a result, it is possible to provide an optimum sediment trapping function according to the sedimentation condition upstream of the transparent erosion control dam without reducing the strength.

The permeable erosion control dam according to claim 3 is characterized in that, in claim 2, a steel form for holding the first tubular body and the second tubular body is provided.

According to the above arrangement, even when a large number of first tubular bodies and second tubular bodies are arranged in the slit,
Since the first and second cylindrical bodies can be positioned at predetermined positions by the steel frame, the on-site construction can be facilitated.

In the method for manufacturing a permeable sabo dam according to claim 4, a permeable sabo dam that permits the flow of flowing debris during normal flooding and prohibits the flow of flowing debris during abnormal flooding is provided. In the manufacturing method, after cutting the slit in the existing impermeable-type erosion control dam, the first tubular body set to the maximum gravel diameter of the debris that normally flows at the time of flooding is provided in the slit, and then, The feature is that the slit is filled with concrete.

According to the above construction, the existing impermeable-type sabo weir is added to the permeable-type sabo weir having a predetermined strength and having a desired flow-down performance of prohibiting the flow-down only in the event of abnormal water discharge. Can be modified.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, the permeable sabo dam 1
A concrete structure 2 provided with a slit 3, a tubular body 5 provided in the slit 3, and a filling concrete portion 4 formed by filling concrete into the slit 3 provided with the tubular body 5. The water tapping section 6 is provided on the downstream side of the concrete structure 2.

The concrete structure 2 is laid in the width direction of the river so as to block the flow of debris. The concrete structure 2 is made of unreinforced concrete and has side wall portions 2 a arranged on both sides in the width direction of the river and a remaining portion 2 b sandwiched between two slits 3. The side wall portion 2a and the remaining portion 2b are not limited to the unreinforced concrete structure, and may be reinforced concrete structure or the like.

In each of the slits 3, a plurality of tubular bodies 5 are provided in the vertical direction so that the upstream side and the downstream side of the concrete structure 2 communicate with each other. The tubular body 5 is made of a steel pipe, and is set to have a diameter of the maximum gravel of debris that flows at the time of abnormal flooding. The axis of the tubular body 5 is aligned with the downflow direction of the river. The number and the installation positions of the tubular bodies 5 to be provided are not limited to those in the present embodiment, and the number and the installation positions are set according to the state of the debris flow at the installation location of the transmission-type sand control dam 1 and the purpose of the installation. Just decide the position.

The tubular body 5 allows the flowing debris to permeate to the downstream side during normal flooding, and prohibits the flowing debris and a large amount of water flow during abnormal flooding. Then, when the abnormal water discharge state is changed to the normal water discharge state, the debris accumulated on the upstream side of the permeation-type erosion control dam 1, the water and the sand and the like in the irrigation pond are gradually caused to flow down to the downstream side at the time of the abnormal water discharge.

Each slit 3 provided with the above cylindrical body 5
Is filled with concrete.
It is said that. Due to the interlocking concrete portion 4, the side wall portions 2a, 2a provided on both sides in the width direction of the river and the remaining portion 2 are provided.
b and the concrete structure 2 as a whole are integrated.

A water tapping portion 6 is provided on the downstream side of the concrete structure 2 constructed as described above. The water tapping portion 6 has a width larger than the arrangement interval of the slits 3, and both end portions are bent upward in the side wall portion 2a. Then, the water tapping part 5 receives the falling water overflowing / permeating from the concrete structure 2 and flowing it downstream.

A method of manufacturing the transmission type sabo dam 1 having the above structure will be described. In the following description, a case will be described in which an existing impermeable sabo dam is manufactured by modifying an existing impermeable sabo dam.

First, the degree of rainfall, the condition of the ground, and the past debris flow / flood occurrence situation at the installation location of the transparent erosion control dam 1 are investigated. Then, the state of debris flow during normal flood due to small or medium scale rainfall and the state of debris flow / flood during abnormal flood due to large scale rainfall are grasped. At the same time, the maximum gravel diameter of debris and rubble discharged by the debris flow during an abnormal flood and the amount of water discharged by the flood are estimated. In addition, the normal flood means a flood on a scale that does not cause a problem in the area on the falling side even if the debris flows down from the permeation-type erosion control dam 1, and the abnormal flooding means the permeation-type erosion control dam 1.
The flow of debris / flood from a flood means flooding of a scale that causes a problem in the area on the downflow side.

The maximum gravel diameter estimated as described above is used as a catching size to prevent flooding during normal flooding due to medium-scale rainfall, and to provide an optimal sediment trapping function and abnormal water flow uptake during abnormal flooding. To have the ability
The diameter and arrangement of the tubular body 5 are set. The debris and the like having a size larger than the trap size is prohibited from flowing down by the tubular body 5, and the debris and the like having a size smaller than the trap size are allowed to flow down from the tubular body 5. In addition, an amount of water that exceeds the flow capacity of the tubular body 5 is dammed up upstream of the permeable erosion control dam 1, and an irrigation pond is formed.

As for the gravel and the like contained in the debris flow that flows down at the time of abnormal flooding, the weight of the gravel as a single body is large near the water bottom of the river and the gravel diameter is large, but as the water surface approaches, the weight of the gravel as a single body increases. Small and small gravel diameter is flowing. Therefore, in order to capture the entire amount of debris flow, it is desired that the tubular body 5 provided in the slit 3 has a large diameter and a large capturing size in the lower portion of the concrete structure 2, while it has a small diameter and a capturing size in the upper portion. Small things are desired. In addition, the bottom of the river is not flat in the width direction, and there is a difference in depth depending on the flow of water flowing through the river and the degree of bending of the river. It is also necessary to understand the condition of debris and gravel contained in the debris flow of the cross section of the river by the shape of the water bottom.

Next, as shown in FIG. 1, the tubular body 5 determined as described above is installed by removing a part of concrete from the concrete structure 2 of the impermeable sabo barrier. The slit 3 which can be formed is formed. Then, the tubular body 5 is installed in the slit 3 with the diameter and arrangement determined as described above. Concrete is filled in the slits 3 in which the tubular body 5 is installed to form the interlocking concrete portion 4, whereby the side wall portion 2a and the remaining portion 2b are firmly connected. This allows
The existing impermeable sabo dam will be converted into the permeable sabo dam 1 having high performance.

Next, the operation of the transmission type sabo dam 1 manufactured as described above will be described.

When a flood occurs due to rain or snow melt, the flood causes debris, gravel, and trees to be washed away, resulting in a debris flow and a flood. When the debris flow flows into the permeation-type erosion control dam 1 during such an abnormal flood, debris is captured by the permeation-type erosion control dam 1 because boulders are concentrated at the tip of the debris flow. Then, while depositing only debris, gravel and the like on the upstream side of the transmission type erosion control dam 1, water is made to flow downstream. At this time, the amount of accumulated debris is planned and set in advance by adjusting the diameter and arrangement of the tubular body 5. When the flood flows into the permeable erosion control dam 1, a large amount of water flows up the upstream of the permeable erosion control dam 1 to form an irrigation pond.
When earth and sand flow into this irrigation pond, the earth and sand are accumulated while forming a sediment shoulder. At this time, the speed at which the flood is dammed
The amount is adjusted by adjusting the diameter and arrangement of the tubular body 5.
It is planned and set in advance.

In the above-mentioned permeable erosion control dam 1, the debris of all sizes can be flowed down from the tubular body 5 during normal flooding. On the other hand, at the time of normal water discharge, if debris of a size larger than the maximum gravel diameter flows, the tubular body 5 can prevent the debris of this size from flowing down. When a large amount of water flows, it is dammed upstream of the transparent sabo dam 1, and sediment is temporarily deposited in the irrigation basin formed by it, and then it is made to flow down from the tubular body 5 at the end of the flood. You can At this time, even if a load of debris or earth and sand is applied to the transmission-type erosion control dam 1, the concrete structure 4 is formed in the slit 3 and is integrated as a whole, so that the concrete structure 2 collapses or becomes horizontal. It does not fall down. In addition, by setting the diameter of the tubular body 5 to the maximum gravel diameter of the debris that normally flows at the time of flooding, the slit 3 in which the tubular body 5 is provided is formed to have a large width or many slits 3 are formed. Even in such a case, since it is integrally formed as described above, it has a predetermined strength or more,
It does not collapse or fall sideways.

By such an operation, at the time of normal water discharge, which is a small-scale or medium-scale water discharge, the flowing debris is caused to flow down through the tubular body 5 of the permeation-type erosion control dam 1, resulting in a large-scale water discharge. In case of abnormal flood, transparent sabo dam 1
It is possible to prevent the flow of debris as a whole. Therefore, in the downstream region of the transparent erosion control dam 1, there is no reduction in the riverbed or receding of the coastline, and even if a large-scale debris flow occurs, a certain amount of debris is temporarily blocked. There will be no flooding that will cause problems in the downstream areas.

As described above, the permeable erosion control dam 1 of this embodiment allows the flow of flowing debris during normal flooding and prohibits the flow of flowing debris during abnormal flooding. In the dam, a concrete structure 2 provided with a slit 3 for transmitting debris to the downstream side and laid so as to block the flow of debris, and a concrete structure 2
Of the cylindrical body 5 (first cylindrical body), which is provided in the slit 3 so as to communicate the upstream side and the downstream side of the water, and is set to the diameter of the maximum gravel diameter of the debris that normally flows at the time of flooding, and the slit 3 And a filling concrete portion 4 formed by filling concrete therein.

As a result, the gap between the slit 3 and the tubular body 5 is closed by the tubular body 5, so that the entire dam 1 is integrated, so that the slit 3 is formed with a large width. Or, even when many slits 3 are formed, the transmission type sand control dam 1 can be maintained at high strength. Therefore, by setting the diameter of the tubular body 5 to the maximum gravel diameter of the debris that normally flows at the time of flooding, even if the slit 3 in which the tubular body 5 is provided has a large width, the permeable sand control dam 1 Can be provided with a predetermined strength or more. In addition, the permeable erosion control dam 1 having the strength of a predetermined level or more as described above can flow debris of all sizes from the tubular body 5 at the time of normal water outflow, while the abnormal water outflow causes the size of debris to exceed the maximum gravel diameter. When a large-sized debris flows, it is possible to prohibit the debris of this size from flowing down by the tubular body 5. Therefore, it is possible to prohibit the flowing-down only at the time of abnormal flooding.

Further, the method of manufacturing the transparent sabo dam 1 according to the present embodiment allows the flowing debris to flow down during normal flooding and prohibits the flowing debris flow during abnormal flooding. In the manufacturing method of 1., after the slit 3 is cut in the existing impermeable sabo dam, the tubular body 5 is set to have a diameter of the maximum gravel diameter of debris that normally flows at the time of flooding.
The (first tubular body) is provided in the slit 3, and then the slit 3 is filled with concrete. As a result, it is possible to modify the existing impermeable-type sabo dam to the permeable-type sabo dam 1, which has a desired strength and has a strength not less than a predetermined level and prohibits the spillage only when an abnormal water flow occurs.

In the present embodiment, the case where the tubular bodies 5 are arranged in the vertical direction has been described, but the present invention is not limited to this. That is, the tubular body may be arranged in the width direction of the river. In FIG. 2, the transparent erosion control dam 11 has a tubular body 15 provided in a slit 13 of a concrete structure 12 having side wall portions 12a on both sides in the river width direction and a slit 13 provided with the tubular body 15. And a filling concrete portion 14 formed by filling concrete. In this way, since the permeable concrete sabo dam 11 is integrated as a whole by the stuffed concrete portion 14, the slit 13 can be provided large and the tubular body 15 can be arranged in the width direction of the river. As a result, it is possible to increase the permeation cross-sectional area in the river width direction and improve the debris flow capability at a predetermined height of the permeation-type erosion control dam.

Further, in the present embodiment, the case where the diameters of the tubular members are all the same has been described, but the present invention is not limited to this. That is, the cylindrical bodies having different diameters may be arranged. In FIG. 3, the transparent erosion control dam 21 is arranged in the slit 23 of the concrete structure 22 having the side wall portions 22a on both sides in the width direction of the river, and the first tubular body 25a is arranged in the lower region of the slit 23. A second tubular body 25b having a smaller diameter than the first tubular body 25a is provided in an upper region inside the slit 23 above the tubular body 25a. As a result, debris with a maximum gravel diameter that flows below the debris flow is prohibited by the first tubular body 25a, and debris and driftwood with a diameter less than the maximum gravel diameter that flows above the debris flow is the second tubular body 25b. The flow of water is prohibited in the area and the debris flow can be sufficiently dammed in the event of an abnormal flood. The diameter of the second cylindrical body 25b to be installed is not limited to a single diameter as long as it is smaller than that of the first cylindrical body 25a, and may be a plurality of diameters. For example, the diameter of the second tubular body 25b may be reduced as it is located from the lower side to the upper side of the slit 23. In this case, the state of debris flow (large debris exists on the lower side, It is possible to obtain a transmission type sabo dam corresponding to the situation where small debris are present.

Further, in the present embodiment, the case where the slit 3 of the concrete structure 2 is a non-reinforced concrete structure in which only concrete is filled has been described, but the present invention is not limited to this. That is, as shown in FIGS. 4 and 5, the permeable erosion control dam 31 includes the first tubular body 35a and the second tubular body 35a provided in the slit 33 of the concrete structure 32 having the side wall portions 32a on both sides in the river width direction.
Steel form 37 for holding the tubular body 35b, and steel form 37
It may be configured to include a filling concrete portion 34 formed by filling concrete in the slit 33 provided with. As a result, the first tubular body 35a and the second tubular body 35a
Even when a large number of tubular bodies 35b are arranged in the slit 33, the first and second tubular bodies 35a and 35b can be positioned at predetermined positions by the steel mold 37. On-site construction can be facilitated.

[0036]

As described above, according to the invention of claim 1, the gap between the slit and the first cylindrical body is closed by the filling concrete portion, so that the entire dam is integrated. Therefore, even when the slits are formed to have a large width or a large number of slits are formed, the permeation-type erosion control dam can be maintained at high strength. Therefore, by setting the diameter of the first tubular body to the maximum gravel diameter of the debris that flows during normal flooding, even if the slit in which the first tubular body is provided has a large width, Can be provided with a predetermined strength or more. Thus, the permeable erosion control weir basin having a strength of a predetermined level or more can flow debris of all sizes from the first tubular body during normal flooding, while abnormal flooding causes the size of the gravel to exceed the maximum gravel diameter. When a large-sized debris flows, it is possible to prohibit the debris of this size from flowing down by the first tubular body. Therefore, the flowing-down can be prohibited only at the time of abnormal flooding.

According to the second aspect of the present invention, the debris having a maximum gravel diameter or more flowing under the debris flow is prohibited by the first tubular body, and the debris or driftwood having a diameter less than the maximum gravel flowing above the debris flow is prohibited. , The second tubular body is prohibited from flowing down. As a result, it is possible to provide an optimum sediment trapping function according to the sedimentation condition upstream of the transparent erosion control dam without reducing the strength.

According to the third aspect of the invention, even when a large number of the first tubular body and the second tubular body are arranged in the slit, the first and second tubular bodies are made of steel. Since it can be positioned at a predetermined position, the on-site construction can be facilitated.

According to the fourth aspect of the present invention, the existing impermeable sabo barrier is an existing impermeable sabo barrier that has a desired strength and has a strength not less than a predetermined level and prohibits the flow only when an abnormal water flow occurs. Can be modified.

[Brief description of drawings]

FIG. 1 is a perspective view of a transparent sabo dam.

FIG. 2 is a perspective view of another transparent sabo dam.

FIG. 3 is a perspective view of another transparent sabo dam.

FIG. 4 is a perspective view of another transparent sabo dam.

5 is a cross-sectional view of the transparent sabo dam in FIG. 4 in the river downflow direction.

[Explanation of symbols]

1 Transmission type Sabo dam 2 concrete structures 3 slits 4 Paved concrete section 5 Cylindrical body (first cylindrical body)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shima ▲ length ▼             1-3-18 Wakihama-cho, Chuo-ku, Kobe-shi, Hyogo               Kobe Steel, Ltd. Kobe Head Office

Claims (4)

[Claims] 1. A permeation-type erosion control dam that allows the flow of debris that flows during normal flooding and prohibits the flow of debris that flows during abnormal floods, comprising a slit that allows the debris to pass downstream. A concrete structure laid so as to block the flow of the debris, and provided in the slit so that the upstream side and the downstream side of the concrete structure communicate with each other, the maximum gravel diameter of the debris flowing at the time of the normal flooding A permeable erosion control weir, characterized in that it has a first tubular body set to a diameter of 1 and a filling concrete portion formed by filling the slit with concrete. 2. The first tubular body is arranged in a lower region of the slit, and the second tubular body having a smaller diameter than the first tubular body is provided in an upper region of the slit above the first tubular body. The permeable erosion control weir according to claim 1, wherein a tubular body is provided. 3. The permeation-type sand control weir according to claim 2, further comprising a steel mold holding the first tubular body and the second tubular body. 4. A method of manufacturing a permeable erosion control dam, which allows flowing debris during normal flooding and prohibits flowing debris during abnormal flooding. After notching the slit, the first tubular body set to the diameter of the maximum gravel diameter of the debris that normally flows at the time of flooding is provided in the slit, and then the concrete is filled in the slit. Type Sabo weir.