JP3996407B2 - Sediment accumulation structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an accumulation structure of earth and sand formed in a dam lake, a reservoir and a river.
[0002]
[Prior art]
In general, there is almost no flow of water in the dam lake, so sediments such as fine-grained soil called floating road and floating sand that have flowed along with muddy water accumulate on the bottom of the lake. When this amount of sediment is increased, the amount of stored water decreases and the original function of the dam cannot be exhibited, so dredging is performed by various methods.
[0003]
[Problems to be solved by the invention]
However, the wash road with an average particle size of about 0.017 mm and suspended sand with a particle size of 0.15 to 0.25 mm are deposited as a thin layer over the entire lake bottom, so the dredging area becomes wide. There was a problem that efficient dredging was not possible.
[0004]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an integrated structure capable of efficient dredging of earth and sand.
[0005]
[Means for Solving the Problems]
The gist of the sediment accumulation structure of the present invention for solving the above-described problems is that an earth-and-sand channel is formed from the upstream portion of the inflow slope channel through which water flows to the bottom of the reservoir, and the earth-and-sand channel is inflow slope. A horizontal dike projecting laterally so as to block a part of the inflow slope road, and a vertical dike constructed along the inflow slope road from the tip of the horizontal dike to the reservoir bottom It consists of a dike. In addition, it included that a dike that crossed the inflow slope was built upstream of the horizontal dike. In addition, a sediment accumulation part is formed near the outflow port of the earth and sand conduit, and the sediment accumulation part is located at an appropriate distance from the sediment accumulation area near the outflow port and the tip of the longitudinal dike. Including the formation of a dam built across the river. In addition, the earth and sand guide channel is formed so as to be gradually widened from the upstream side to the downstream side. It also includes that a dam extending in the opposite direction to the outlet was built at the tip of the longitudinal dike. It also includes the formation of silt protectors on the longitudinal dike. Further Yokoshirube flow Tsutsumi, Tateshiruberyu Tsutsumi are those comprising been embankments in sediment discharged from the bottom of the lake.
[0006]
Since muddy water containing wash load and suspended sand flows into the dam lake (or reservoir) through the earth and sand conduit, there is no sediment such as wash load and suspended sand in the dam lake, that is, not the entire dam lake. It can be accumulated in some places. Moreover, these earth and sand can be accumulated in the place where the most efficient dredging can be made according to the shape of the dam lake. In addition, a large dike can be used to block large stones and tree branches. It is possible to accumulate earth and sand such as wash roads and floating sand that flowed into the dam lake together with muddy water in the sediment accumulation area at the bottom of the lake. In addition, turbid water can flow slowly from the upstream side to the downstream side by the earth and sand guide channel formed gradually wider from the upstream side to the downstream side, so sediment such as wash load and floating sand can be put into the sediment accumulation area. Can be integrated. In addition, from the dam provided at the tip of the longitudinal dike in the direction opposite to the outlet, it is possible to accumulate sediment in the sediment accumulation area without diffusing earth and sand such as wash load and floating sand. The sedimentary soil discharged from the bottom of the lake is used to build up the vertical dike and dam, so that the sediment can be effectively used. By collecting earth and sand such as wash roads and suspended sand at a certain location in the dam lake, it is possible to perform efficient dredging work at one place and wash roads where efficient dredging work can be performed. And sediment such as floating sand.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an earth and sand accumulation structure (hereinafter referred to as an accumulation structure) according to the present invention will be described with reference to the drawings. In each embodiment, the same components are described with the same reference numerals, and only different components are described with different reference numerals. This accumulation structure is formed in a dam lake, a reservoir, and a river. In the following embodiment, an accumulation structure formed in a dam lake will be described.
[0008]
1 and 2 show an integrated structure 1 of the first embodiment. The integrated structure 1 includes an inflow slope 3 for flowing water into a dam lake 2, an earth-and-sand channel (hereinafter referred to as a channel) 4 for flowing muddy water containing earth and sand such as a wash road and floating sand, and the channel It is composed of an earth and sand accumulating portion (hereinafter referred to as an accumulating portion) 5 formed in the vicinity of the outlet of the passage 4. In addition, the above wash load refers to fine-grained soil having an average particle size of about 17 μm, and suspended sand refers to soil having a particle size of 0.15 to 0.25 mm.
[0009]
The diversion channel 4 includes a horizontal diversion channel 7 provided on the downstream side of the diversion dike 6 of the inflow slope channel 3 and a vertical diversion channel built on the inflow ramp channel 3 from the tip of the horizontal diversion channel 7 to the bottom of the lake. It is composed of the bank 8. The horizontal dike 7 and the vertical dike 8 are constructed by sedimentary soil discharged from the bottom of the lake. The former blocks a part of the inflow slope 3 from the right bank (toward the downstream side) to the left bank. In this way, the latter is constructed so that the conduit 4 gradually becomes wider from the front end of the lateral conduit 7 to the bottom of the lake. Further, a silt protector 9 is formed in a submerged dike portion from the submerged portion to the tip portion of the longitudinal dike 8.
[0010]
As shown in FIG. 3, the silt protector 9 is formed by fixing a lower end portion of a curtain 10b suspended by a floater 10a to a submerged dike portion 8a. Further, by providing a gap 10c of about 1 m between the floater 10a and the curtain 10b, the force acting on the silt protector 9 due to the water level difference between the inside of the lake and the guide channel 4 is reduced.
[0011]
Further, although the guide channel 4 is formed on the left bank side in FIG. 1, whether it is formed on the left or right side is determined in consideration of the hydraulic characteristics, topographic characteristics, etc. of the dam lake 2. Furthermore, when the water depth of the inflow slope 3 is shallow, the conduit 4 can be formed only by the silt protector 9 or by the longitudinal dike 8 alone.
[0012]
The channel 4 formed in this way, like a natural river, the muddy water 12 containing earth and sand such as a wash road and floating sand gradually flows from the upstream side to the downstream side, and the outlet corresponding to the estuary. The flow stops at around 13.
[0013]
On the other hand, the accumulation part 5 in the vicinity of the outlet 13 is composed of a sediment accumulation area (hereinafter referred to as an accumulation area) 14 and dams 15 and 16 constructed by sedimentary soil discharged from the lake bottom. In this way, the dams 15 and 16 formed around the accumulation area 14 form depressions in the vicinity of the outlet, that is, the accumulation portion 5. Therefore, the muddy water 12 containing the wash load and the floating sand separated from the large stones at the diversion bank 6 flows into the dam lake 2 from the channel 4 and is retained by the front dam 15. The other side is not diffused by the backside dam 16, and earth and sand settle here.
[0014]
4 and 5 show the integrated structure 17 of the second embodiment. The accumulation structure 17 is characterized in that the accumulation portion 5 is formed in a hollow portion where earth and sand such as a wash road and floating sand easily accumulate using the terrain of the dam lake 2 and is formed naturally in the vicinity of the outlet 13. The projection 18 thus formed replaces the front dam 15 and forms the accumulation portion 5 together with the rear dam 16. As described above, the accumulation structure 17 has the same configuration as the accumulation structure 1 of the first embodiment except that the accumulation portion 5 is formed using the topography of the dam lake 2. Therefore, as described above, the muddy water 12 separated from a large stone or the like by the diversion dike 6 flows into the dam lake 2 from the channel 4 and is stopped by the protrusions 18, and is otherwise separated by the rear dam 16. It does not spread.
[0015]
【The invention's effect】
Since muddy water containing earth and sand such as wash road and floating sand flows into the dam lake through the channel, the earth and sand can be accumulated at a certain place in the dam lake, not the whole dam lake. .
[0016]
It is possible to accumulate earth and sand such as wash roads and floating sand in the most efficient dredging area according to the shape of the dam lake.
[0017]
A large dike can be used to block large stones and tree branches.
[0018]
It is possible to accumulate earth and sand such as wash road and floating sand that flowed into the dam lake together with muddy water in the accumulation area of the lake bottom.
[0019]
Muddy water can flow gradually from the upstream side to the downstream side by the guide channel formed gradually wider from the upstream side to the downstream side, so that sediment such as wash load and floating sand can be accumulated in the accumulation area. .
[0020]
The dam can collect earth and sand such as wash roads and suspended sand in the accumulation area without spreading.
[0021]
The sedimentary soil discharged from the lake bottom can be used effectively because the horizontal and horizontal dike, vertical and horizontal dike and the dam are built.
[0022]
Since sediments such as wash roads and suspended sand can be accumulated at certain locations in the dam lake, sediment can be accumulated at locations where efficient dredging can be performed, as well as efficient dredging. be able to.
[Brief description of the drawings]
FIG. 1 is a plan view of an integrated structure according to a first embodiment.
FIG. 2 is a longitudinal sectional view of FIG.
3A is a cross-sectional view of FIG. 1, and FIG. 3B is a front view of a silt protector.
FIG. 4 is a plan view of an integrated structure according to a second embodiment.
FIG. 5 is a cross-sectional view of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 17 Accumulation structure 2 Dam lake 3 Inflow slope road 4 Conduction flow path 5 Accumulation part 6 Split dike 7 Lateral dike 8 Vertical dike 9 Silt protector 10a Float 10b Curtain 10c Crevice 12 Muddy water 13 Outlet 14 Accumulation area 15 , 16 Weir 18 Projection

Claims (7)

  An earth and sand channel is formed from the upstream part of the inflow slope path where water flows into the reservoir bottom, and the earth and sand channel is formed in the lateral direction so as to block a part of the inflow slope path in the upstream part of the inflow slope path. An earth and sand accumulation structure characterized by comprising a projecting horizontal dike and a vertical dike built along an inflow slope from the tip of the horizontal dike to the reservoir bottom.   2. The earth and sand accumulation structure according to claim 1, wherein a diversion bank crossing the inflow slope road is built on the upstream side of the horizontal diversion bank.   A sediment accumulation part is formed near the outlet of the earth and sand conduit, and the sediment accumulation part has an outlet at an appropriate distance from the tip of the longitudinal dike and the sediment accumulation area near the outlet. 3. The earth and sand accumulation structure according to claim 1, wherein the earth and sand accumulation structure is formed by a dam built so as to cross.   The earth and sand accumulation structure according to any one of claims 1 to 3, wherein the earth and sand guide channel is formed to be gradually wider from the upstream side to the downstream side.   The sediment accumulation structure according to any one of claims 1 to 4, wherein a dam extending in a direction opposite to the outflow port is built at a front end portion of the longitudinal dike.   The sediment structure according to any one of claims 1 to 5, wherein a silt protector is formed on the longitudinal dike. Yokoshiruberyutsutsumi, Tateshiruberyu Tsutsumi sediment integrated structure according to any one of claims 1 to 6, characterized in that it is the embankment in sediment discharged from the bottom of the lake.

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