JP3588639B2 - Underground drainage system and method of operating the system - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an underground drainage system that guides inflow water, such as rainwater, that flows from a small river or the like via a headrace and a shaft into a groundwater channel, guides the inflow water to an underground pumping station, and discharges the water to a river or the sea. It relates to the operation method of the system.
[0002]
[Prior art]
In urban areas, the area of pavement has expanded along with the development of surrounding areas, and the proportion of rainwater that naturally penetrates into the ground has decreased. The amount of water may increase in a short time. In order to cope with such an increase in the amount of inflow water, an underground drainage system having a configuration in which the diameter of a groundwater channel of an underground drainage facility is increased or the number and capacity of drainage pumps are increased.
[0003]
However, in the underground drainage system configured as described above, it is possible to cope with a rapid increase in inflow of inflow water into the groundwater channel, but since the number and capacity of the drainage pumps are increased, it becomes difficult to control the drainage pumps. There is a disadvantage that.
[0004]
Therefore, a movable overflow weir is installed in the headrace to take in water from a river or a drainage channel, etc. Underground drainage systems have been proposed in which the amount of wastewater can be adjusted (for example, Japanese Patent Application Laid-Open Nos. 5-222760 and 4-363427).
[0005]
[Problems to be solved by the invention]
However, in the case of the above-mentioned prior art in which a movable overflow weir is provided, there is a problem that it is very difficult to operate the overflow weir according to the amount of rainfall. That is, when heavy rainfall causes the water levels of a plurality of rivers or drainage channels to rise sharply, a large amount of inflow water flows from the rivers or drainage channels into the underground waterway through the overflow weir. Then, the inflow water flowing into the underground waterway is discharged to other rivers and the sea by a pump installed downstream of the underground waterway, but it takes time to start this pump. It is impossible to efficiently drain the inflow water in the underground waterway.
[0006]
In the case where a reservoir for temporarily storing inflow water is installed underground, the buried position of the underground waterway is deeper by the depth of the reservoir, which increases the required head of the pump, There are economic problems such as an increase in costs and equipment costs and an increase in the size of the equipment.
[0007]
An object of the present invention is to provide an underground drainage system capable of efficiently draining inflow water in a groundwater channel by appropriately operating a drainage pump, and also being economically excellent, and a method of operating the system. is there.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a headrace connected to a river or a drainage channel, and a erected underground connected downstream of the headrace, and a lower end of the pier. An underground waterway connected to the ground and provided with a pumping station provided downstream of the underground waterway, and the inflow water taken into the waterway from a river or a drainage channel, etc. In the underground drainage system that flows into the underground waterway and further drains the inflow water in the underground waterway to another river or the sea with the pump of the pump station,
Along with separating the headrace and the pier into two, one of the separated headraces is provided with a low overflow weir having a low height, and the other is provided with a high overflow weir having a high height, The underground waterway is provided with a partition plate that vertically divides the underground waterway into two along the flow of inflow water, and each of the separated shafts is connected to the two divided underground waterways,
In the pumping station, a pump is installed in each of the two divided underground waterways, and the bottom level of the pump is low in the underground waterway communicating with the headrace on the side of the low overflow weir, and the high overflow It is characterized in that it is set high in the groundwater channel that communicates with the headrace channel on the weir setting side.
In addition, a gate capable of shutting off the flow of inflow water can be provided in the headrace channel on the low overflow weir installation side.
[0011]
[Action]
According to the underground drainage system having the above configuration, at the time of a small flood, inflow water from a river or a drainage channel overflows only the low overflow weir and cannot overflow the high overflow weir. Then, the inflow water flowing through the low overflow weir is guided to a pump at a low bottom level through a headrace channel on the side where the low overflow weir is installed, a vertical shaft communicating with the headrace channel, and an underground waterway. Drained to rivers or the sea.
[0012]
At the time of a major flood, inflow water from a river or a drainage channel overflows both the low overflow weir and the high overflow weir. Then, the inflow water flowing through the low overflow weir is guided to the lower pump at the bottom level through the headrace channel on the side where the low overflow weir is installed, the shaft that communicates with the headrace channel, and the underground waterway. The inflow water flowing over the flow weir is guided to the pump at the higher bottom level through a headrace channel on the side of the installation of the Takagoshi weir, a shaft communicating with the headrace channel, and an underground waterway. Thereafter, the inflow water is drained to another river or sea by the two pumps.
[0013]
If a gate capable of blocking the flow of inflow water is installed in the headrace channel on the side of the low overflow weir, the gate will be used to shut off the flow of the low overflow weir during the middle of a small flood and a major flood. The flow of inflow water can be shut off. When the gate is blocked in this way, the inflow water from the river or drainage channel overflows only the overflow overflow weir, and the overflowed inflow water flows into the headrace channel on the side where the weir overflow overflow weir is installed. The water is guided to a pump having a high bottom level through a shaft and an underground waterway which communicate with each other, and is drained to another river or the sea by the pump.
[0014]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual configuration diagram of the underground drainage system of the present invention. This underground drainage system is composed of an intake system, a groundwater channel, and a pump station. First, the water intake system is provided with a headrace 2 connected to the river 1 and piers 3A, 3B connected to the downstream side of the headrace 2 and erected underground. A movable weir 4 that can move up and down is installed at a location where the headrace 2 contacts the river 1. By moving the movable weir 4 up and down, the amount of inflow water flowing from the river 1 into the headrace 2 can be adjusted.
[0015]
The headrace 2 is separated from the middle into two headraces 2A and 2B, and the headrace 2A is provided with a low overflow weir 5A, and the headrace 2B is provided with a high overflow weir 5B. Is installed. The low overflow weir 5A and the high overflow weir 5B are fixed weirs that cannot move up and down. A gate 6 that can move up and down is provided above the low overflow weir 5A. When the gate 6 is moved downward and placed on the low overflow weir 5A, the inflow of water into the headrace channel 2A is reduced. Flow can be blocked. Downstream sides of the headraces 2A, 2B are connected to uprights 3A, 3B erected underground, respectively.
[0016]
The underground waterway 7 is buried underground. As shown in FIG. 2, the inside of the underground waterway 7 is vertically divided into two by a partition plate 8 along the flow of inflow water, and forms flow paths 7A and 7B. The lower end of the stand 3A is connected to the flow path 7A, and the lower end of the stand 3B is connected to the flow path 7B. The groundwater channel 7 is provided with pits 9 (see FIG. 1) connected to manholes in some places.
[0017]
As shown in FIG. 1, drainage pumps 10A and 10B are installed in the pump station. The drainage pump 10A is installed in the channel 7A of the underground waterway 7, and the drainage pump 10B is installed in the channel 7B of the underground waterway 7, and the bottom level of the drainage pump 10B is set higher than the bottom level of the drainage pump 10A. Further, the discharge sides of the drainage pumps 10A and 10B are connected to a river (or sea) 11.
[0018]
In the underground drainage system having the above configuration, when the movable weir 4 is moved downward, inflow water flows from the river 1 into the headrace 2. In the case of a small flood due to the effects of general rainfall, etc., the water level of the river 1 is low. As shown in FIG. 3, the river water level is lower than the height of the weir in the high overflow weir 5B. Cannot overflow. On the other hand, in the low overflow weir 5A, since the river water level is higher than the height of the weir, the inflow water can overflow the low overflow weir 5A if the gate 6 is open. The overflowed inflow water flows into the flow path 7A in the underground waterway 7 through the headrace 2A and the pier 3A, and reaches the pump station at the most downstream of the underground waterway 7 by natural flow.
[0019]
At the pumping station, as shown in FIG. 4, inflow water flows into a flow path provided with a drainage pump (high-lift pump) 10A having a low bottom level, and as the water level of the flow path rises, the drainage pump 10A It starts and discharges inflow water to the river 11. At this time, the drain pump (low head pump) 10B has not been started. 8A is a partition plate erected at the pump station. The partition plate 8A is provided continuously with the partition plate 8 in the underground waterway 7.
[0020]
Next, in the case of a major flood due to the influence of a typhoon or the like, since the water level of the river 1 rises and becomes higher than the heights of the overflow weirs 5A and 5B, the water flows through the headraces 2A and 2B and the piers 3A and 3B. A large amount of inflow water flows into the underground waterway 7. In this case, efficient drainage operation of the pumps cannot be performed due to delays in starting the pumps 10A and 10B installed in the pump station downstream of the underground waterway 7.
[0021]
Therefore, as a first step, the gate 6 is closed as shown in FIG. In this way, the flow of the inflow water on the side of the water conduit 2A is cut off, and the inflow water only on the side of the water conduit 2B that can overflow the high overflow weir 5B flows. Then, the inflow water on the side of the water conduit 2B flows into the flow path 7B of the underground waterway 7 via the vertical shaft 3B, and reaches the pumping station at the most downstream of the underground waterway 7 by natural flow.
[0022]
At the pumping station, as shown in FIG. 6, the inflow water flows into the flow path provided with the drainage pump (low head pump) 10B having a high bottom level, and the drainage pump 10B is driven by the rise in the water level of the flow path. Start up and discharge inflow water to river 1. At this time, if the amount of inflow flowing into the pump well is larger than the discharge amount of the drainage pump 10B due to the influence of a pump start delay or the like, the water level of the pump well rises as shown in FIG. When the water level exceeds the height of the partition plate 8A, the inflow water flows into the flow path on the drain pump 10A side as shown in FIG. Thereby, the drainage movement of the drainage pump 10B can be maintained at a certain level. The inflow water flowing into the flow path on the drain pump 10A side is drained by the drain pump 10A as needed when it reaches a certain level and loses the storage effect.
[0023]
If the water level of the river 1 does not change only by overflowing the high overflow weir 5B as shown in FIG. 5, and there is a danger of further rising, as shown in FIG. The installed gate 6 is opened to allow the inflow water of both the water conduits 2A and 2B to flow. This inflow water flows into the flow paths 7A and 7B via the vertical shafts 3A and 3B, respectively, and reaches the pump well at the most downstream of the underground waterway 7 by natural flow. In this case, since all the inflow water in the flow paths 7A and 7B of the underground waterway 7 flows into the pump well, the water level of each pump well is higher than the height of the partition plate 8A. Therefore, the drainage operation is performed by fully operating both the drainage pumps 10A and 10B.
[0024]
【The invention's effect】
As described above, according to the present invention, since the headrace, the shaft, the underground waterway, and the drainage pump are divided into two systems, it is possible to perform an appropriate pump operation according to the amount of water in the river or the drainage channel, and to efficiently perform the operation. Pump drainage can be performed.
In addition, power costs and equipment costs are not increased or the equipment is not increased in size, which is extremely economical.
[Brief description of the drawings]
FIG. 1 is a conceptual configuration diagram showing an underground drainage system of the present invention.
FIG. 2 is a detailed view of a water intake section.
FIG. 3 is a diagram showing an operation of a water intake unit in the case of a small flood.
FIG. 4 is a diagram showing an operation of a pump station in a case of a small flood.
FIG. 5 is a diagram showing an operation of a water intake unit in a case of a major flood.
FIG. 6 is a diagram showing an operation of a pump station in a case of a major flood.
FIG. 7 is a diagram showing an operation of a water intake unit in the case of a flood.
FIG. 8 is a diagram showing the operation of the pump station in the case of a flood.
[Explanation of symbols]
Reference Signs List 1 river 2, 2A, 2B headrace 3A, 3B, 9 shaft 4 movable weir 5A low overflow weir 5B high overflow weir 6 gate 7 underground waterway 8, 8A partition plate 10A, 10B drainage pump

Claims (4)

A headrace connected to a river or a drainage channel, etc .; a stanch connected to the downstream of the headrace and erected in the ground; and a groundwater channel connected to the lower end of the pier and installed in the ground And a pumping station provided downstream of the underground waterway, and inflow water taken into the waterway from a river or a drainage channel is allowed to flow into the underground waterway through the pier, and further into the underground waterway. In an underground drainage system for draining influent water to another river or the sea with the pump of the pump station,
Along with separating the headrace and the pier into two, one of the separated headraces is provided with a low overflow weir having a low height, and the other is provided with a high overflow weir having a high height,
The underground waterway is provided with a partition plate that vertically divides the underground waterway into two along the flow of inflow water, and each of the separated shafts is connected to the two divided underground waterways,
In the pumping station, a pump is installed in each of the two divided underground waterways, and the bottom level of the pump is low in the underground waterway communicating with the headrace on the side of the low overflow weir, and the high overflow An underground drainage system, wherein the underground drainage channel communicating with the headrace channel on the weir setting side is set high. In the underground drainage system according to claim 1,
An underground drainage system, wherein a gate capable of shutting off the flow of inflow water is provided in the headrace channel on the low overflow weir installation side. In the underground drainage system according to claim 1,
The underground drainage system, wherein the height of the partition plate at the pump station is equal to or higher than the height of the impeller of the pump having a higher bottom plate level. A headrace and a basin for guiding inflow water from a river or a drainage channel to the underground waterway are separated into two, and one of the separated waterways has a low overflow weir with a low height and the other has a high overflow weir. A high overtop weir is installed respectively, and further, a gate capable of blocking the flow of inflow water is provided in the headrace channel on the low overtop weir installation side,
The lower end of the separated pier is connected to a groundwater channel whose inside is divided into two by a partition plate provided in a vertical direction along the flow of the inflow water,
A pump is installed on the downstream side of the two divided underground waterways, and the bottom level of the pump is low in the underground waterway communicating with the headrace on the side where the low overflow weir is installed. In the underground drainage system set higher in the underground waterway that communicates with the headrace on the installation side,
In the case of a small flood, inflow water from a river or a drainage channel is guided to the low-level pump through the headrace channel on the side where the low overflow weir is installed, the shaft and the underground waterway communicating with the headrace channel. , Drained to other rivers or the sea with the pump,
In the case of a major flood, the gate blocks the flow of inflow water of the low overflow weir-side headrace, and inflows from rivers or drainage channels, etc., the headrace on the high overflow weir installation side, Through a shaft and an underground waterway communicating with the headrace, leading to the pump with a high bottom level, draining to another river or the sea with the pump,
Furthermore, in the case of a major flood, the inflow water from a river or a drainage channel, etc. is passed through the headrace channel on the low overflow weir installation side, the shaft and the underground waterway communicating with the headrace channel, and In addition to guiding to the pump, through the headrace channel on the side of the Takagoshi overflow weir, the shaft and the underground waterway communicating with the headrace channel, it is guided to the pump with the higher bottom level, and the inflow water is separated by the two pumps. A method for operating an underground drainage system, comprising draining water to a river or sea.

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