JPH0436208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for installing a simple submersion dam for raising the water level at the uppermost reaches of a river and dispersing running water over a wide area.

(b) Prior art Japanese Patent Application No. 115088/1988, previously submitted by the same applicant, is related to water meandering, bank cutting, and erosion prevention in rivers, but similar concrete blocks are used to convert water flow. Instead of doing,
This method uses blocks to raise the water level and spread water over a wide area of the river basin, and its purpose is completely different from conventional river utilization methods.

(c) Problems to be solved by the invention and means for solving them It is already well known that construction of conventional dams is large-scale and costly, regardless of the size of the river. The invention uses concrete blocks to construct dams in a stepwise manner from downstream to upstream, thereby simplifying the construction work and raising the water level through the dam.
The flow of water is expanded and infiltrated into the river basin by the amount of rise.

In other words, the purpose of this dam is to reduce flooding, and by installing a large number of concrete blocks at the upstream headwaters, it is possible to stop the water that flows out at once from rain during typhoons and reduce the rise in water in the middle reaches. In addition, the meandering at the river mouth was corrected, the water flow was changed to direct current, the speed of the water was increased, and the erosion in the central part of the river accelerated the outflow of water, reducing the increase in water in the midstream part. be.

Furthermore, water that temporarily stagnates upstream becomes groundwater during dry periods and flows out, resulting in an increase in water resources. If we build a dam on a dry river and expand the shallow water surface, we can increase freshwater resources and increase the natural reproduction of all kinds of plants and animals.

Hereinafter, the gist of the present invention will be explained based on embodiments shown in the drawings.

(D) Example Figure 1 is a plan view showing an example of a dam constructed by the construction method of the present invention, Figure 2 is a cross-sectional view along the central flowing water of the river in Figure 1, and Figure 3 is a dam used in dam construction. A plan view of the concrete block, and FIG. 4 is a longitudinal sectional view of the same block.

In the drawing, 1 is a river flowing down in the direction of the arrow.
Concrete blocks are lined up in three stages across the flowing water to form block groups A, B, and C, and each block group is a pair of blocks that are slightly inclined to the base 3 shown in Figures 3 and 4. The base 3 is a high clog-shaped concrete block 2 consisting of plates 4 and 4.
The concrete blocks 2 are arranged in a straight line perpendicular to the flow of the river 1 as shown in the first diagram, with the base being the base, and the concrete blocks 2 are arranged in parallel so that there is no gap between them. In this case, it is possible to provide an appropriate gap by taking into account the speed and volume of the flowing water, but the presence of a gap increases the flow velocity in that part, and in order to scrape off the earth and sand at the bottom of the gap, it is possible to provide as little gap as possible. It is desirable to parallel them closely.

In this embodiment, the concrete block 2 is 2 meters long, 1 meter wide, and 1 meter high, and is installed so that the slopes of the plates 4, 4 face the river flow. in,
When installing, first of all, cross the river 1.
A block group is formed. As a result, the water level becomes high enough to overcome the plate 4, and at the same time, the width of the river becomes correspondingly wide.

As clearly shown in Figure 2, earth and sand is independently and artificially deposited upstream of the A block group, and a second B block group is installed on top of it, thereby lowering the water level. is higher than in the case of A block group, and at the same time the river width is also widened to correspond to the situation on both banks. Furthermore, if we estimate the sediment to the upstream side of the B block group in the same way and construct the next C block group on this estimate, the water surface S when the dam is full will be the same as before, as shown in the second figure. It is located much higher than the water surface S', allowing for good diffusion and infiltration of water to both banks.

(e) Effect As described above, in the present invention, when constructing a dam, the water flow of a river is not dammed, diverted and a dam is built in advance to retain the flow, but concrete blocks 2 are placed in a line on the riverbed. Since the method involves estimating sediment in parallel, the construction itself is extremely easy, and is particularly suitable for small and medium-sized rivers, where water diffuses and permeates over a wide area on both banks of the river as the water level rises. That will happen.

(F) Effects of the invention By constructing many dams as described above from mountainous areas downstream, the width of the river has been significantly expanded.
The diffusion of running water takes place, and the rain source due to evaporation of water,
Because it becomes groundwater through infiltration and becomes a water resource during dry periods, it is possible to revitalize nature. Since the method involves estimating soil and forming the next block group on top of it, it is extremely easy compared to conventional construction methods.It saves materials and the work itself is simple, so it can be easily moved to the desired location. For example, it is effective for easing the flow of fast-flowing rivers, scraping away bridge piers, etc. due to flowing water, and preventing erosion. Furthermore, it is effective against all types of fluids such as mudflows, sandflows, lava flows, etc. It is also effective for converting flow paths and reducing flow velocity, etc.
It has excellent features that can be used in a wide range of fields, and also has the following effects.

By stagnating rainfall in stages starting from the most upstream level, it is possible to lower the rising water level downstream.

The normal flow of water in a basin can be increased to provide distributed water flow.

Since a large amount of water is retained upstream, it becomes a breeding ground for aquatic animals.

As more water stagnates in mountainous areas, more fog is generated, which can replenish water to mountainous plants.

It goes without saying that constructing multiple dams in stages along rivers is extremely effective against flooding, but on the other hand, it is also effective in replenishing water and wet surfaces lost due to urbanization of flat areas. This is what is required of the remaining mountainous areas, which will allow us to restore nature, protect flora and fauna, secure water resources for human society, and convert harmful water during floods into useful water during dry periods. becomes.

Particularly in a situation where forest resources are gradually decreasing, the water level in the midstream can be adjusted by building dams in stages to prevent the rapid increase in water that has fallen in large quantities. Concrete blocks 2, 2 on the downstream side along ...
If they are lined up in a line, the earth and sand around the base 10a of the pier 10 will be gouged out by the flow velocity as shown in Figure 6, making it deeper than the normal bottom 11 (dashed line 13). Due to the installation, earth and sand will be accumulated up to the chain line 12, thereby preventing the piers from being washed away.

Furthermore, as shown in Fig. 7, by installing concrete blocks 2 in the shape of scales in meandering parts of the river, even if the water is flooded when the water is high, it will flow down the center of the river when the water is low.
The bottom of the central part is eroded, and the flow is eventually changed to a straight line, which is extremely effective in appropriately preventing erosion in meandering parts.

[Brief explanation of drawings]

Figure 1 is a plan view showing an example of a dam constructed using the construction method of the present invention, Figure 2 is a sectional view taken along the central flowing water of the river in Figure 1, and Figure 3 is a plan view of concrete blocks used in the dam construction. , FIG. 4 is a longitudinal sectional view of the same block. Fig. 5 is a plan view showing the concrete block of the present invention used as a bridge pier, Fig. 6 is a side view showing its function and effect, and Fig. 7 is a plan view showing another method of use. A, B, C... Concrete block group, 1...
...River, 2...Concrete block, 3...Foundation, 4...Plate.

Claims (1)

[Claims] 1 A large number of concrete blocks in the shape of an inverted high geta, each with a plate protruding from a base plate facing the flowing water, are installed in parallel across the flowing water of the river to form a first group of blocks and raise the water level. Then, soil is deposited on the upstream side of the block group, and a second block group is formed on top of the deposited soil to further raise the water level, thus sequentially forming a plurality of block groups, A submergence dam construction method characterized by increasing the water level in stages to spread water over a wide area.