JP6692379B2 - dam - Google Patents

Description

  The present invention relates to a dam installed in a river or the like.

  In rivers such as mountains, dams are installed to prevent sediment-related disasters due to typhoons and heavy rains (see, for example, Patent Document 1). The dam prevents the rocks and driftwood contained in the debris flow from passing through while allowing water to pass through. The walls of the dam dam the debris flow and weaken the rocks and driftwood. In recent years, in order to capture only rocks and driftwood without blocking the passage of water, a slit is formed in a part of the dam, and this slit is provided with a trap-shaped trap body made of steel pipes, etc. A mold dam is constructed (see, for example, Patent Document 2).

In recent years, in order to suppress damage caused by sediment disasters, attempts have been made to newly install catchers in the water passage part even for existing dams that do not have catchers. As shown in FIG. 10, in order to provide the catching body 103 on the existing dam 100, it is necessary to raise the sleeve portion 105 around the catching body 103 in order to secure the water passage portion 104. By raising the circumference of the capturing body 103, as shown in FIG. 11, while capturing the driftwood or the like 106 with the capturing body 103, the space formed above it can be used as the water passage portion 107.
Further, as shown in FIG. 12, when the catching body 111 is provided on the existing dam 110 having a short floor width (width along the flow direction of the river), the upstream side or the downstream side of the water passage portion 112 of the dam 110. The belly portion 113 is provided at the bottom, and the catching body 111 is provided by utilizing the bottom of the water passage portion 112 and the belly portion 113.

Japanese Patent Publication No. 2-55566 JP, 2005-63840, A

However, if the weir is raised, the external force of the debris flow that acts on the wall also becomes large, so the strength of the weir becomes insufficient, and cost and time are required for improvement work to eliminate the insufficient strength.
Also, in so-called impermeable dams that do not have traps, because the width of the water passage is narrow in order to control the flow of water, the traps that are provided in the water passage become smaller, and the It will become clogged and will easily overflow from the sleeve of the dam. As a result, not only the function of catching driftwood etc. cannot be fully exerted, but also improvement work on the downstream side of the dam is required in preparation for an overflow, resulting in cost and time. On the other hand, it may be possible to expand the water passage, but this also costs money and time.
In addition, even if a belly portion is provided on the dam, the construction work will be costly and time consuming.
Also, in order to newly fix the trapping body to the existing dam, it is necessary to put concrete for the water passage part and then to place concrete for the trapping body, which requires cost and time such as construction of scaffolding. Will end up.

  Then, this invention is made | formed in view of the said subject, and an object of this invention is to provide the dam which can install a capture body more easily than before and can suppress the cost and time required for construction.

  In order to solve the above-mentioned problems, the present invention is a dam having a water passage part, which is provided on a wall surface on the upstream side of the dam, and includes a trap body that traps driftwood flowing from upstream and allows the running water to pass. At least a part of the trapping body is provided at a position facing away from the water passage portion on the upstream side of the water passage portion.

  Further, it is preferable that the capturing body is inclined toward the upstream side as it goes upward.

  Further, the capturing body has a first leg portion having one end fixed to an upstream wall surface of the dam, one end fixed to an upstream wall surface of the dam, and the other end to the first leg portion. It is preferable to provide a plurality of pillars having the connected second legs and a beam connecting the pillars.

  Further, it is preferable that the first leg portion inclines toward the upstream side from one end toward the other end.

  Further, it is preferable that the second leg portion is arranged along an inclination of the ground where the dam is installed.

  Further, it is preferable that the other end of the first leg portion is above the bottom surface of the water passage portion.

  Further, it is preferable that the length of the capturing body is longer than the width of the water passage portion.

  Further, it is preferable that the pillars are arranged at a distance corresponding to ½ of the maximum driftwood length or the maximum gravel diameter.

  According to the present invention, the capturing body can be installed more easily than before, and the cost and time required for construction can be suppressed.

(A) is a front view of the dam, and (b) is a side view of the dam. It is the front view which looked at the dam from the upstream. It is the perspective view which looked at a dam from the upper right side. It is the perspective view which looked at a dam from the lower right side. It is a top view of a dam. It is a side view of a dam for explaining the state of a trap when sediment is deposited on the upstream side of the dam. In a river sweep section, (a) is a front view of a weir for explaining the state of capturing driftwood and allowing water to pass, (b) is a side view of the weir, and (c) is a side view of the weir. It is a top view. In the debris flow section of a river, (a) is a front view of a dam for explaining the state of capturing driftwood and sediment and allowing water to pass through, (b) is a side view of the dam, and (c) is the dam. FIG. (A) is the front view which looked at the dam which concerns on a modification from the upstream, (b) is the perspective view which looked at the dam which concerns on a modification from the upper right side. In the prior art, (a) is a front view of a dam for explaining a method of raising the dam to provide a trap body, and (b) is a side view of the dam. In the prior art, (a) is a front view of a weir for explaining a state in which driftwood is captured and water is allowed to pass through the weir of FIG. 9, and (b) is a side view of the weir. FIG. 9 is a side view of a dam for explaining a state in which a belly portion for providing a catching body is provided on the dam in the related art.

  A preferred embodiment of the present invention will be described with reference to the drawings. It should be noted that the embodiment described below is merely an example, and various embodiments can be adopted within the scope of the present invention.

<Structure of dam>
As shown in FIG. 1, the dam 1 includes a main body 2 and a capturing body 3. The dam 1 has a catcher 3 newly installed on an existing main body 2 already installed in a river to enhance the function of catching driftwood and rocks.

(Body)
As shown in FIG. 1, the main body 2 has its bottom portion buried in the ground and is constructed so as to extend along the width direction of the river so as to cross the river. The main body 2 is constructed of, for example, concrete or soil cement. In the main body 2, the wall surface facing the upstream or downstream side of the river may be a steel plate wall formed by connecting a plurality of steel segments, and the inside thereof may be filled with concrete or soil cement.
At the upper end near the center of the main body 2 along the width direction of the river, a water passage portion 21 is formed so as to be cut (recessed) so that the upper end is lower than the surroundings. The water passage portion 21 is formed so as to collect the flowing water flowing from the upstream in the vicinity of the center of the main body 2 and flow it to the downstream.
The main body 2 includes an upstream wall portion 22 facing the upstream side of the river and a downstream wall portion 23 facing the downstream side of the river. The upstream wall portion 22 inclines toward the upstream side as it goes downward from the bottom surface of the water passage portion 21. The downstream wall portion 23 inclines toward the downstream side as it goes downward from the bottom surface of the water passage portion 21.

(Catcher)
As shown in FIGS. 1 to 5, the trap 3 traps the driftwood flowing from the upstream of the river and allows the running water to pass through, and is provided on the upstream wall portion 22 of the main body 2. The capturing body 3 is provided along the extending direction of the main body 2, that is, along the width direction of the river. At least a part of the capturing body 3 is provided on the upstream side of the water passage portion 21 so as to be separated from the water passage portion 21 and to face the water passage portion 21. The capturing body 3 inclines toward the upstream side as it goes upward. The capturing body 3 is constructed such that the length L in the width direction is longer than the width W of the water passage portion 21. The capturing body 3 is provided in the main body 2 so that at least a part thereof is located above the bottom surface of the water passage portion 21 of the main body 2.

The capturing body 3 includes one beam portion 31 extending along the width direction of the main body 2 (width direction of the river) and a plurality of beam portions 31 connected at predetermined intervals along the extending direction of the beam portion 31. And a column portion 32.
The beam part 31 and the column part 32 are formed of, for example, a steel pipe. The column portion 32 includes a first leg portion 32a and a second leg portion 32b.
One end (lower end) of the first leg portion 32a is fixed to the upstream wall portion 22 of the main body 2 with anchor bolts and nuts. The first leg portion 32a is connected to the beam portion 31 at the other end (upper end). As a result, the pillar portions 32 are connected by the beam portion 31. The first leg portion 32a is provided on the upstream wall portion 22 so as to incline toward the upstream side from one end fixed to the upstream wall portion 22 toward the other end.
One end of the second leg portion 32b is fixed to the upstream wall portion 22 of the main body 2 by an anchor bolt and a nut. The second leg 32b is connected at the other end to the central portion in the longitudinal direction of the first leg 32a. Here, if the second leg portion 32b is arranged along the slope of the riverbed on the upstream side, the force of the debris flow can be received along the axial direction of the second leg portion 32b. The second leg portion 32b is preferable because it can suppress the force of peeling off the second leg portion 32b from the upstream wall portion 22 of the main body 2. As a result, the pillar portion 32 is constructed in a substantially λ shape in a side view, and the first leg portion 32a is longer than the second leg portion 32b.
The interval S between the adjacent pillars 32 is half the length of the maximum driftwood that is assumed to flow through the river, or the length corresponding to the maximum gravel diameter that is assumed to flow through the river. Is preferably

<How to install the capturing body>
Next, a method of installing the trap 3 when the trap 3 is provided on the main body 2 of the existing dam to construct the dam 1.
First, the installation position of the capturing body 3 in the upstream wall portion 22 of the main body 2 is drilled, an anchor bolt is embedded in the formed hole, and mortar or the like is filled in the hole and fixed.
Next, the anchor bolt is passed through a flange portion provided at one end of the first leg portion 32a and the second leg portion 32b, and fixed with a nut. Here, in the capturing body 3, the beam portion 31 and the column portion 32 each made of a steel pipe are joined in advance by welding or the like, and are fixed by nuts while being suspended by a crane or the like. Here, the length of the capturing body 3 (the length of the beam portion 31) is preferably constructed to be at least longer than the width of the water passage portion 21 of the main body 2.
When the capturing body 3 is provided on the main body 2, the capturing body 3 is attached to the main body 2 so that a part of the capturing body 3 is located above the bottom surface of the water passage portion 21 of the main body 2.
Through the above steps, the trap 3 can be installed in the main body 2 of the existing dam, and the dam 1 having an enhanced function of catching driftwood of the existing dam is constructed.

As described above, by providing the catching body 3 on the upstream wall portion 22 of the main body 2 of the existing dam, the function of catching driftwood, earth and sand, etc. can be added, and the function as the dam 1 can be improved. Can reduce disasters.
Further, since the capturing body 3 can be provided in advance in the main body 2 in consideration of the occurrence of a debris flow due to a typhoon or heavy rain, a sediment disaster can be prevented in advance.
Moreover, since the 1st leg part 32a of the capture | acquisition body 3 inclines toward an upstream side as it goes to an upper part, the driftwood and the boulder which flowed in go down below the dam 1 along the 1st leg part 32a. Thus, the effect of preventing overflow of driftwood and the like can be further enhanced.
Further, since the capturing body 3 is arranged so as to project above the bottom surface of the water passage portion 21, as shown in FIG. 6, after a long time has passed, earth and sand accumulate on the upstream side of the dam 1. Even if it does, the function of capturing driftwood can be maintained.
Further, since the capturing body 3 is provided so that the portion facing the water passage portion 21 is separated from the water passage portion 21, it is possible to capture the driftwood or the like before the driftwood or the like flows into the water passage portion 21.
Moreover, since the 2nd leg part 32b is arrange | positioned along the slope of the ground (river bottom) where the dam 1 is installed, the collision energy of the driftwood etc. which are transmitted from the 1st leg part 32a is set along an axial direction. Since the second leg 32b can be received, the force of the second leg 32b attempting to separate from the main body 2 can be minimized.
In addition, since the length of the capturing body 3 is longer than the width of the water passing portion 21, most of the drift wood or the like can be captured before the driftwood or the like flows into the water passing portion 21.

Here, when the trap body 3 is provided in the existing water passage portion 21, it is necessary to raise the main body of the dam in order to provide a new water passage portion. Since it is provided separately from the water passage portion 21, it is not necessary to raise the main body 2 and the improvement work for eliminating the insufficient strength of the dam 1 is unnecessary.
In addition, in order to prepare for overflow from the main body 2, it is not necessary to perform improvement work on the downstream side of the dam 1, widening work of the water passage part 21, and belly work, so it is possible to reduce the construction cost and the construction period. You can
Further, in order to raise the main body 2 and install the capturing body 3, it is not necessary to install concrete for fixing the capturing body 3 after the concrete of the water passage portion 21 is set up, and the existing main body 2 can be greatly expanded. No need to improve.
Therefore, the capturing body 3 can be installed on the main body 2 more easily than before, and the construction cost and the construction period can be shortened.

  Here, if the installation location of the dam 1 is a river sweep section, as shown in FIG. 7, only the driftwood 41 is captured by the capturing body 3, and the running water 42 passes through the capturing body 3 and the water passage portion 21. Be led to. As a result, the driftwood 41 accumulates in the opening of the water passage portion 21 and obstructs the flow of water, and it is possible to prevent overflow from the sleeve portion of the main body 2 due to an increase in water volume, and the dam 1 needs to be raised. Disappears. Therefore, the capturing body 3 can be installed so that the driftwood 41 can be effectively captured without modifying the existing dam, and the cost and time required for the construction can be suppressed.

  On the other hand, if the location where the dam 1 is installed is in the debris flow section of the river, as shown in FIG. Be led to. As a result, the driftwood 41 and the earth and sand 43 are accumulated in the opening of the water passage portion 21 to obstruct the flow of water, and it is possible to prevent overflow from the sleeve portion of the main body 2 due to an increase in the volume of water, so that the dam 1 is closed. There is no need to raise it. Therefore, the capturing body 3 can be installed so that the driftwood 41 and the sand 43 can be effectively captured without modifying the existing dam, and the cost and time required for the construction can be suppressed.

<Other>
The present invention is not limited to the above embodiment. For example, the structure of the capturing body can be freely changed as long as it has a function of capturing driftwood and boulders. In addition, the method of fixing the capturing body to the main body can be freely changed as long as it is arranged at a position satisfying the above-mentioned conditions.
Further, the capturing body is not limited to being attached to an existing dam, and may be constructed together with the main body when constructing the dam.

<Modification>
Next, a dam 1A according to a modification will be described with reference to FIG. In the following description, only the portion different from the dam 1 according to the above-described embodiment, particularly the capturing body 5, will be described.
The capturing body 5 includes one beam portion 51 extending along the width direction of the main body 2 (width direction of the river) and a plurality of beam portions connected along the extending direction of the beam portion 51 at predetermined intervals. And a column portion 52.
The beam portion 51 and the column portion 52 are formed of, for example, a steel pipe. The column portion 52 includes a first leg portion 52a and a second leg portion 52b. The distance S1 between the adjacent pillars 52 is half the length of the maximum length of driftwood assumed to flow through the river, as in the distance S between the pillars 32 in the above-described embodiment, or It is preferable that the length is equivalent to the maximum gravel diameter expected to flow through the river.
The beam portion 51 and the column portion 52 (the first leg portion 52a and the second leg portion 52b) of the capturing body 5 have the same configuration as the beam portion 31 and the column portion 32 of the capturing body 3 and therefore are specifically described. The description of the detailed configuration is omitted.
The capturing body 5 is constructed so as to be longer than the width of the water passing portion 21, that is, the pillar portions 52 provided at both end portions in the width direction (river width direction) of the capturing body 5 are at least the main body. 2 is disposed on the upstream wall 22 side. Specifically, in the capturing body 5, three pillars 52 of the pillars 52 on both end sides in the width direction face (cover) the main body 2 on the side of the water passage portion 21 in the width direction. It is installed in. In other words, when the interval S1 between the pillar portions 52 and the pillar portions 52 is 1 span, the capturing body 5 is constructed so as to face the main body 2 by 2 spans. Of the two spans facing the main body 2, one span on the water passing portion 21 side may be at least partially facing the main body 2.
Further, the range of the capturing body 5 facing the main body 2 is, for example, 1 depending on the maximum length of driftwood, the maximum gravel diameter, the scale of the dam 1 to be installed, etc. It can be appropriately changed so as to face the main body 2 by a span, a span of 3 or more.
As described above, the catching body 5 extending to the position facing the main body 2 in the width direction with respect to the water passage portion 21 widens the range in which the driftwood and boulders that have flowed are captured in the width direction, and driftwood and boulders are present. Can be effectively prevented from wrapping around from the side of the capturing body 5.

1, 1A Dam 2 Main body 3, 5 Capture body 21 Water passage part 31, 51 Beam part 32, 52 Column part 32a, 52a First leg part 32b, 52b Second leg part

Claims (11)

A dam having a water passage,
Provided on the wall surface on the upstream side of the dam, and equipped with a trap body for trapping the driftwood flowing from the upstream and passing the running water,
At least a part of the capturing body is provided at a position facing away from the water passage portion on the upstream side of the water passage portion ,
The dam is characterized in that the capturing body is inclined toward the upstream side as it goes upward . The capturing body is
A first leg having one end fixed to the upstream wall of the dam, and a second leg having one end fixed to the upstream wall of the dam and the other end connected to the first leg. A plurality of pillars having a section,
A beam connecting the pillars to each other,
The dam is provided with the dam according to claim 1 . The dam according to claim 2 , wherein the first leg portion is inclined toward the upstream side from one end toward the other end. The dam according to claim 2 or 3 , wherein the second leg is arranged along an inclination of the ground on which the dam is installed. The other end of the said 1st leg part is above the bottom face of the said water passage part, The dam bank as described in any one of Claim 2 to 4 characterized by the above-mentioned. A dam having a water passage ,
Provided on the wall surface on the upstream side of the dam, and equipped with a trap body for trapping the driftwood flowing from the upstream and passing the running water,
At least a part of the capturing body is provided at a position facing away from the water passage portion on the upstream side of the water passage portion,
The capturing body is
One end has a leg portion fixed to the wall surface on the upstream side of the dam,
The other end of the leg portion is above the bottom surface of the water passage portion. The capturing body is
A plurality of pillar portions including the leg portion and a second leg portion having one end fixed to a wall surface on the upstream side of the dam and the other end connected to the leg portion;
A beam connecting the pillars to each other,
Equipped with
The embankment according to claim 6, which is characterized in that. The dam according to claim 6 or 7, wherein the leg portion is inclined toward the upstream side from one end toward the other end. The dam according to claim 7, wherein the second leg portion is arranged along an inclination of the ground on which the dam is installed. The dam body according to any one of claims 6 to 9 , wherein the capturing body is inclined toward the upstream side as it goes upward. The dam according to any one of claims 1 to 10 , wherein a length of the capturing body is longer than a width of the water passage portion.