JP4785094B2 - River water storage facility, method of controlling the flow velocity of water flow to the river water storage facility, and method of depositing sediment in the river water storage facility - Google Patents

Description

  The present invention relates to a river water storage facility formed in a riverbed.

  Conventionally, for example, in the event of heavy rain, for the purpose of preventing rainwater from flowing out into the river, or for the purpose of using rainwater for fire prevention or for watering flower beds, vegetable gardens, etc. Various attempts have been made to store rainwater in vacant lots or in the underground of parking lots and bicycle parking lots.

An example of this type of rainwater storage facility is described in Patent Document 1.
This rainwater storage facility forms a primary storage tank by installing a cylindrical body with a rectangular cross-section made of concrete in a water storage part formed by digging the ground, and resin inside the ring surrounded by the primary storage tank A secondary storage tank having a water storage space formed by three-dimensionally arranging skeleton blocks is formed.

The feature of this rainwater storage facility is that rainwater flowing in from the outside is first stored in the primary storage tank, and the overflow of the primary storage tank is stored in the secondary storage tank.
As a result, the earth and sand contained in the rainwater that has flowed in from the outside through the drainage ditch etc. is first settled in the primary storage tank, and only the wrinkled water flows to the secondary storage tank side, and the earth and sand are as secondary as possible. It does not accumulate in the storage tank.
In addition, since the primary storage tank side is formed of a concrete cylindrical body as described above, it is quite robust. Therefore, it is easy to make a structure in which a cleaning worker can enter. On the other hand, since the secondary storage tank is made of a resin skeleton block, the mechanical strength is lower than that of the primary storage tank. Therefore, it is not easy for the secondary storage tank side to secure a space enough for a cleaning worker to enter. However, as described above, one of the features is that since it is originally designed so that earth and sand do not easily enter the secondary storage tank side, there is no need for a cleaning worker to enter.

JP 2006-348476 A

By the way, because of the recent global warming phenomenon, for example, large-scale floods, which are said to be abnormal weather, have become frequent. For this reason, it has not been considered so far to provide the rainwater storage facility described in Patent Document 1 up to the riverbed, but recently, in the case of heavy rain, a reservoir such as a reservoir located near the river. It is not possible to deal with it alone, and proposals have been made to temporarily store the river water in the riverbed at the riverbed and to return the river water that had been temporarily stored back to the river when the river flooding subsided. .
In that case, for example, a design concept different from the rainwater storage facility described in Patent Document 1 described above is required.

That is, in the case of a conventional rainwater storage facility, since rainwater usually flows from the drainage ditch, the momentum is not so strong, and the amount of inflow per unit time is not so great.
On the other hand, in the event of a flood, the flow rate of water flowing from a river into a water storage facility formed in the basement of the riverbed and the flow velocity thereof are much higher than those of the rainwater storage facility. Specifically, it is estimated that a water volume of several tons per second flows.
In this way, if you want to build a water storage facility on the riverbed, you will need a completely different concept. For example, it is necessary to construct a river water storage facility that can withstand the momentum of the flowing water. However, specific proposals have not yet been made in publicly known documents including Patent Document 1.

  In view of the foregoing problems, an object of the present invention is to provide a river water storage facility that can sufficiently withstand the momentum of water flowing into a storage facility during a flood and can be used for a long period of time.

In order to achieve the above object, the river water storage facility of the present invention temporarily includes an overflow weir that faces the river bank and the river water that is formed behind the overflow weir and has passed over this overflow weir. A reservoir for storing and reducing the flow velocity, and a three-dimensional space retaining skeleton block provided inside the ground of the riverbed to store the river water that has flowed through the reservoir. A river water reservoir, and a concrete speed reducing block provided between the river water reservoir and the derating pond, for reducing the flow rate of the river water by hitting the river water against a side wall. The plurality of deceleration blocks are provided in one or more rows, and the deceleration block is arranged with one side facing the side facing the river water reservoir and faces the river reservoir One side and the side opposite to the one side Is characterized in that river water that has exceeded the weir opening for flowing into the river water reservoir is al provided.

In addition, the river water reservoir has a resin skeleton block arranged vertically and horizontally so as to fill the water storage space, and partitions the river water reservoir into a side closer to the speed reduction block and a side closer to the speed reduction block. The sediment control partition is provided so as to surround the deceleration block, and the sediment control partition is formed by a plurality of plate members fixed by sandwiching the sediment control partition between adjacent resin skeleton blocks. A gap is formed between them, and the water that has entered from the speed reduction block side may flow into the river water storage section partitioned by the sediment control partition from the gap.

Still further , a plurality of manholes may be provided at a time around the deceleration block in a region surrounded by the deceleration block and the sediment control partition so as to surround the deceleration block. Further, the river water reservoir may be one in which concrete plate materials are spread on the inner side surface and the bottom surface, or a water permeable sheet made of non-shrinkable cloth is spread.

In addition, the flow rate and flow velocity control method for the river water storage facility according to the present invention includes an overflow weir provided to face the river bank, and the overflow weir formed behind the overflow weir. A reservoir that temporarily stores the river water and reduces the flow velocity thereof, and a skeleton block that is provided by digging the ground of the riverbed to store the river water that has flowed in through the reservoir A three-dimensionally arranged river water reservoir, and a concrete speed reducer that is provided between the river water reservoir and the diminishing basin to reduce the river water flow velocity by hitting the river water against the side wall. And a plurality of the speed reduction blocks are provided in one or more rows, the speed reduction block is disposed with its one side facing the side facing the river water reservoir, and One side facing the river water reservoir and facing this one side The side surface is characterized in that the opening for river water which has beyond the weir flows into the river water reservoir is provided.
In addition, the method for depositing earth and sand in the river water storage facility according to the present invention includes an overflow weir that faces the river bank and a river that is formed behind the overflow weir and passes over the overflow weir. A reservoir for reducing the flow velocity of the reservoir, and a three-dimensional space retaining skeleton block provided inside the riverbed to dig up the ground of the riverbed to store the river water flowing through the reservoir. A river water reservoir, and a concrete deceleration block provided between the river water reservoir and the reduction basin, for reducing the flow velocity of the river water by hitting the river water against a side wall. A plurality of the speed reduction blocks are provided in one or more rows, the speed reduction block being arranged with one side facing the side facing the river water reservoir, and in the river water reservoir The front side and the side facing this side An opening is provided for the river water that has passed over the overflow weir to flow into the river water reservoir, and the river water reservoir has resin frame blocks arranged vertically and horizontally so as to fill the reservoir space, and the deceleration On the side close to the block, a sediment control partition that divides the river water reservoir into a side near to the speed reduction block and a side far from the speed reduction block is provided so as to surround the speed reduction block, and the sediment control partition is adjacent to the resin skeleton block. Formed by a plurality of plate members sandwiched between, and a gap is formed between the plate members. It is controlled and flows into the river water reservoir section partitioned by the sediment control partition from the gap.

  According to the river water storage facility of the present invention thus configured, since the river water that enters the river water storage part over the overflow weir from the river, the momentum can be scraped by the decelerating pond and the deceleration block, Even if the space-holding skeleton blocks arranged three-dimensionally in the river water reservoir, that is, vertically and horizontally, are skeleton blocks made of resin, the possibility of damage can be greatly reduced. Therefore, a river water storage facility that can be used for a long time can be obtained.

  As described above, according to the present invention, it is possible to provide a river water storage facility that can sufficiently withstand the momentum of water flowing into a storage facility during a flood and can be used for a long time.

It is a schematic plan view which shows one Example of the river water storage facility of this invention. It is a partial sectional view in the XX line of the river water storage facility of the present invention shown in FIG. It is an enlarged plan view of the inflow part of the river water storage facility of this invention. It is the further enlarged plan view of the inflow part of the river water storage facility of this invention shown in FIG. It is a top view which shows an example of the deceleration block which concerns on the river water storage facility of this invention. It is a top view which shows the other example of the deceleration block which concerns on the river water storage facility of this invention.

Hereinafter, an embodiment of the river water storage facility according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a plan view showing an embodiment of a river water storage facility according to the present invention, and FIG. 2 is a partial cross-sectional view taken along line XX in FIG.
As shown in FIG. 1, a river water storage facility 1 according to the present invention is formed by digging down a riverbed of a first-class river 3, for example, and its planar shape is, for example, substantially rectangular and its area is, for example, about 1500 m 2. The river water reservoir 2 shown in FIG. 2 has a river water reservoir 2 having a height of approximately 3000 tons and a water reservoir of approximately 3000 m. In FIG. 1, reference numeral 4 is an inflow portion where river water (hereinafter simply referred to as water) flows from the river into the river water storage facility 1, and reference numeral 5 is a temporary storage of the water into the river when the flood has subsided. It is the outflow part to return. The outflow part 5 may not be formed so as to be returned to the river, but may be formed so as to flow into the nearest reservoir such as a reservoir or the nearest sewer main buried underground.

The river water storage facility of the present invention will be described in more detail. As illustrated in FIG. 2, when described from the river 3 side, for example, a concrete overflow overflow weir 6 is provided so as to face the river bank. The height and width of the overflow weir 6 are determined in consideration of the dangerous water level of the river 3 in the vicinity where the river water storage facility 1 is installed. In addition, what is formed behind the overflow weir 6 is a diversion basin 7 for temporarily storing river water that has passed over the overflow weir 6 and reducing the flow velocity thereof.
In order to further reduce the momentum of the water flowing into the river water reservoir 2 through the dewatering pond 7, a concrete speed reducing block 8 is installed between the river water reservoir 2 and the diversion reservoir 7.

The deceleration block 8 is made of concrete and has a rectangular cylindrical section as will be described later. And it is arrange | positioned with the one side surface 8a facing the side which faces the river water storage part 2 side, and each side surface 8b and the side surface 8b which opposes this one side surface 8a each pass the depressurization pond Openings 9 and 9 are provided for the water that has flowed into the river water reservoir 2. That is, the water that has flowed in through the depressurization pond 7 hits the deceleration block 8 and decelerates, passes through the openings 9 and 9 formed in the side surfaces 8a and 8b of the deceleration block 8, and reaches the river water reservoir. Flows into 2.
Although not particularly shown, if necessary, the deceleration blocks 8 may be arranged in front of the river water reservoir 2 in two rows or more. If it does in this way, the momentum of the water which flows in from the river 3 can further be decelerated.

By the way, in the river water reservoir 2, for example, a resin or concrete plate 10 may be laid on the inner bottom surface, and a resin or concrete plate may be placed on the side if necessary. A side wall may be formed by stacking the shape wall material. If necessary, a water-permeable sheet made of a nonwoven fabric or the like may be laid on the bottom and side surfaces. If it does in this way, there exists an advantage which can prevent the invasion of the earth and sand from the ground surface side into the river water reservoir 2.
After finishing the bottom and side surfaces of the river water reservoir 2 in this way, a space holding skeleton block 11 made of resin, for example, polypropylene (hereinafter simply referred to as the resin skeleton block 11) is three-dimensionally arranged in the space inside the river water reservoir 2. In other words, a space holding skeleton, that is, a water storage space, is formed by connecting a plurality of pieces vertically and horizontally.

In FIG. 2, only a part of the resin skeleton block 11 is shown to simplify the drawing, and most of the skeleton block 11 is omitted. In practice, however, the resin skeleton block 11 is not left in the river water reservoir 2. Is incorporated.
The resin skeleton block 11 shown in FIG. 2 is made of a resin in which a square frame is integrally formed at both ends (upper and lower in the figure) of a cylindrical body. Each of the connecting protrusions has a fitting hole into which the connecting protrusion is fitted, and the connecting protrusions are fitted into the mating fitting holes and sequentially connected to form a water storage space.
Here, the description has been made that the adjacent resin skeleton blocks 11 are connected to each other, but depending on the design, they are not necessarily connected but may be simply arranged vertically and horizontally. However, it is preferable that the two are connected to each other when the water flows into the river water reservoir 2 because the installation position can be stably maintained without losing the momentum of the water.

By the way, there are various shapes of the resin skeleton block 11. For example, in addition to the resin skeleton block 11 shown in FIG. 2, various types such as a box shape, a cylindrical shape, and a tray shape have been devised. Therefore, the present invention is not limited to the shape shown in FIG.
Incidentally, the water storage porosity of the space holding skeleton formed of the resin skeleton block 11 is preferably 90% or more.

Once the space holding skeleton by the resin skeleton block 11 is formed in the entire river water reservoir 2, if necessary, a resin or concrete top plate 12 is placed thereon, and if necessary, a water-permeable sheet is placed thereon. A covering layer 13 is formed by, for example, backfilling the dug up soil. Incidentally, the thickness of the coating layer 13 is usually about 1 m to 2 m.
In FIG. 2, reference numeral 15 denotes a manhole for observing the state in the river water reservoir 2, for example, the sedimentation state of sediment, and reference numerals 20 and 21 denote bottom surfaces of the reservoir before the river reservoir 2 is installed. The underlayers such as the rubble layer laid in are shown.

  Furthermore, reference numeral 16 in FIG. 2 denotes a sediment control partition. This sediment control partition 16 is, for example, fixed by sandwiching a resin plate material between the side surfaces of the above-described square frame bodies of the adjacent resin framework block 11. Incidentally, as shown in FIG. 3, the river water reservoir 2 is divided into two, a side closer to the speed reduction block 8 and a side farther by the sedimentation suppression partition 16. By doing in this way, the water which has flowed toward the river water reservoir 2 through the deceleration block 8 collides with the sediment control partition 16 and further decelerates, and the river water partitioned by the sediment control partition 16 The contained earth and sand are settled and deposited on the side of the water reservoir 2 near the speed reduction block 8.

  As a result, as shown in FIG. 3, if the manhole 15 is provided on the speed reduction block 8 side when viewed from the sedimentation control partition 16, the manhole 15 is used to clean the side near the speed reduction block 8 of the river water reservoir 2, In particular, the deposit can be removed. That is, most of the earth and sand contained in the water does not enter the back side of the river water reservoir 2, that is, the left side of the sediment control partition 16 in FIG. 2, but before the sediment control partition 16, that is, Sedimentation on the right side of the sediment control partition 16 in FIG. Therefore, most of the river water reservoir 2 that is difficult to clean, that is, the left side of the river water reservoir 2 in FIG. 2 does not require cleaning (removal of deposits) over a long period of time.

  By the way, this sediment control partition 16 is formed of a plurality of resin plates as described above, but there is an appropriate gap between the plates, and water that has entered from the speed reduction block 8 side. Flows in from the gap so as to leak to the left side (back side) of the river water reservoir 2 partitioned by the sediment control partition 16. Of course, when the amount of inflow from the inflow section 4 is large, or the amount of water stored in the river water storage section 2 increases as time passes, and the water level rises, the water flows beyond the upper end of the sediment control partition 16. In some cases, it flows into the back of the river water reservoir 2.

  FIG. 3 is a plan view of the inflow portion 4 of the river water storage facility 1 of the present invention. In FIG. 3, a part of the manhole 15 is omitted for easy understanding of the figure. However, in order to pump out the internal sediment to the outside, the number of manholes 15 is increased along the sediment control partition 16. This will improve workability.

By the way, in the river water storage facility 1 shown in FIG. 1, although the planar shape is substantially rectangular, the planar shape may be formed in, for example, a substantially L shape or a trapezoidal shape according to the shape of the riverbed.
Further, in FIG. 3, the width of the front of the inflow portion 4 is L, and the width of the opening 9 formed in each deceleration block 8 is ln (n = 1, 2,... Mm: the number of the deceleration blocks 8). In this case, it is preferable to set L = l1 + l2 +... Lm so that the water that has passed over the overflow weir 6 does not easily overflow to the outside in the depressurization pond 7.

FIG. 4 is an enlarged view of FIG. As shown in FIG. 4, the openings 9 and 9 formed on the side surfaces 8a and 8b of the concrete speed reducing block 8 are formed so as to be shifted from each other, and are generally arranged in a staggered manner. Yes. Incidentally, in FIG. 4, the side walls of the deceleration block 8 are hatched in order to make the state of the opening 9 easier to understand.
When the openings 9 are arranged in a staggered manner in this way, as shown by the arrows, the water that has passed through the damping basin 7 is more likely to collide with the side wall of the deceleration block 8, and the flow velocity can be further reduced. . As a result, the energy of the flowing water when colliding with the resin skeleton block 11 in the river water reservoir 2 is further reduced, and the water storage space formed by the resin skeleton block 11 of the river water reservoir 2 is less likely to be damaged.
By the way, when two or more rows of the deceleration blocks 8 are installed, the momentum of the water can be further reduced by arranging the openings 9 of the deceleration blocks 8 arranged in two or more rows in a staggered arrangement as a whole. preferable.

FIG. 5 is an enlarged cross-sectional view of only the deceleration block 8 portion. The opening 9 provided in the deceleration block 8 has a rectangular shape and is indicated by a cross, but the shape of the opening 9 is not limited to a rectangle but may be other shapes such as a circle or an ellipse.
In the above-described embodiment, the openings 9 are formed in a staggered arrangement, but the openings 9 formed on the opposing side surfaces 8a and 8b of the deceleration block 8 are not limited to the staggered arrangement as shown in FIG. It may be linear. For example, when the flow velocity or flow rate of water flowing into the river water storage section 2 of the river water storage facility 1 is not so large, the deceleration block 8 shown in FIG.
If the speed reduction blocks 8 shown in FIG. 6 are arranged in two or more rows and the openings 9 of the speed reduction blocks 8 in the adjacent rows are shifted from each other, the openings 9 can be arranged in a zigzag as a whole, and the flow velocity can be reduced. Is preferable.
Further, the number of openings 9 provided on the side surfaces 8a and 8b of the deceleration block 8 is not limited to one, and may be plural. The position may be in an aligned state or may be random.

In the above-described embodiment, the resin skeleton block 11 is used to form a water storage space in the river water reservoir 2, but it goes without saying that a concrete skeleton block may be used.
However, it is preferable to use the resin skeleton block 11 because the cost is low and the transportability is good because it is light and lightweight, so that the construction is easy to carry out. Therefore, both the material cost and the construction cost can be reduced.

Further, in the above-described embodiment, the basin 7 is provided behind the overflow weir 6, but in places where the flow rate of water during flooding is not so large, water is temporarily stored and the flow rate is reduced. For example, it may be a guide water channel that guides water to the speed reduction block 8 and the river water reservoir 2. That is, the reduction basin 7 may be eliminated and replaced with a shallow guide channel.
In addition, at the bottom of the river water reservoir 2, the groundwater level at the installation location of the river reservoir 2 is likely to rise, and there is a possibility that a large buoyancy may act on the river reservoir 2 formed by the resin skeleton block 11 or the like. . If there is such a fear, concrete may be placed with an appropriate thickness on the lower surface of the river water reservoir 2.

As described above, according to the river water storage facility of the present invention, the water entering the river water storage section through the overflow weir from the river at the time of flooding is scraped off by the basin or the deceleration block. Even if the skeleton block that is three-dimensionally stacked in the section and forms the space holding skeleton, that is, the water storage space, is a skeleton block made of resin, the risk of being damaged by the flowing water is greatly reduced. Can do. Therefore, a river water storage facility that can be used for a long time can be obtained.
In addition, if a resin skeleton block can be used as the skeleton block, the construction of the river water reservoir is remarkably facilitated. This is because the resin skeleton block is lightweight and easy to carry, so that the workability of construction work is remarkably improved. Therefore, according to the river water storage facility of the present invention, since the resin skeleton block can be used, the price of the skeleton block can be reduced and the construction cost can be reduced. Therefore, the construction cost can be greatly reduced.

  As described above, according to the present invention, it is possible to provide a river water storage facility that can sufficiently withstand the momentum of water flowing into a storage facility during a flood and can be used for a long period of time.

DESCRIPTION OF SYMBOLS 1 River water storage facility 2 River water storage part 3 River 4 Inflow part 5 Outflow part 6 Overflow weir 7 Reduction basin 8 Deceleration block 9 Opening part 11 Resin framework block 13 Cover layer 15 Manhole 16 Sedimentation suppression partition

Claims (6)

An overflow weir that faces the riverbank, a basin formed behind the overflow weir to temporarily store the river water that has crossed the overflow weir and reduce its flow velocity, and A river water reservoir having a three-dimensional space retaining skeleton block provided inside the riverbed to dig down the ground of the river bed to store the river water flowing through the pond, and the river water reservoir A concrete speed reducing block for reducing the flow rate of the river water by hitting the river water against the side wall,
A plurality of the deceleration blocks are provided in one or more rows,
The deceleration block is disposed with its one side facing the side facing the river water reservoir, and the overflow weir on one side facing the river water reservoir and the side facing the one side it openings are found provided for flowing the river water is the river water reservoir which has exceeded the features that river water reservoir facilities. The river water reservoir has a resin skeleton block arranged vertically and horizontally so as to fill the water storage space, and is divided into sand that partitions the river reservoir into a side closer to the speed reduction block and a side farther from the speed reduction block. Suppression partition is provided so as to surround the deceleration block, and the sediment control partition is formed by a plurality of plate members fixed between adjacent resin skeleton blocks, and there is a gap between the plate members. 2. The river water storage facility according to claim 1, wherein the water that has been formed and has entered from the speed reduction block side flows into the river water storage section partitioned by the sediment control partition from the gap. 3. The river water according to claim 2 , wherein a plurality of manholes are provided so as to surround the speed reduction block around the speed reduction block in an area surrounded by the speed reduction block and the sediment control partition. Water storage facility.   The river water according to any one of claims 1 to 3, wherein the river water reservoir is formed by laying concrete plates on the inner side surface and the bottom surface, or by laying a water permeable sheet made of nonwoven fabric. Water storage facility. An overflow weir that faces the riverbank, a basin formed behind the overflow weir to temporarily store the river water that has crossed the overflow weir and reduce its flow velocity, and A river water reservoir having a three-dimensional space retaining skeleton block provided inside the riverbed to dig down the ground of the river bed to store the river water flowing through the pond, and the river water reservoir A concrete speed reducing block for reducing the flow rate of the river water by hitting the river water against the side wall,
A plurality of the deceleration blocks are provided in one or more rows,
The deceleration block is disposed with its one side facing the side facing the river water reservoir, and the overflow weir on one side facing the river water reservoir and the side facing the one side A method for controlling a flow rate and a flow rate of a water flow to a river water storage facility, wherein an opening for allowing the river water that has passed over the river to flow into the river water storage unit is provided. An overflow weir that faces the riverbank, a basin formed behind the overflow weir to temporarily store the river water that has crossed the overflow weir and reduce its flow velocity, and A river water reservoir having a three-dimensional space retaining skeleton block provided inside the riverbed to dig down the ground of the river bed to store the river water flowing through the pond, and the river water reservoir A concrete speed reducing block for reducing the flow rate of the river water by hitting the river water against the side wall,
A plurality of the deceleration blocks are provided in one or more rows,
The deceleration block is disposed with its one side facing the side facing the river water reservoir, and the overflow weir on one side facing the river water reservoir and the side facing the one side An opening is provided for the river water that has crossed the river to flow into the river water reservoir,
Further, the river water reservoir has a resin skeleton block arranged vertically and horizontally so as to fill the reservoir space, and partitions the river reservoir into a side closer to the speed reduction block and a side closer to the speed reduction block. A sand suppression partition is provided so as to surround the periphery of the deceleration block, and the sediment control partition is formed by a plurality of plate members sandwiched between adjacent resin skeleton blocks, and there is a gap between the plate members. The water flowing in from the speed reducing block side is controlled in flow rate and flow velocity of the water flow to the river water storage facility, and flows into the river water storage section partitioned by the sediment control partition from the gap. A method for depositing sediment in river water storage facilities.

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