JPH07207716A - Stratified pumping well - Google Patents

Abstract

PURPOSE:To provide a simple stratified pumping well capable of separately pumping water from a plurality of aquifers. CONSTITUTION:A drilled hole 31 is formed, so as to penetrate an impermeable layer 1 and reach an aquifer 3 existing underneath and, then, the hole is internally divided into upper and lower sections at the position of the layer 1 via a water stop screen 34, so as to be capable of stopping water. Also, a plurality of well tubes 33 and 34 respectively corresponding to aquifers 2 and 3 as pumping objects are arranged, so that the screens 35 and 36 respectively come to be located at the positions of the aquifers 2 and 3. Then, ground water flowing from each aquifer into the tubes 33 and 34 is pumped up with lifting pumps 39 and 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stratified pumping well for individually pumping groundwater from a plurality of aquifers existing underground.

[0002]

2. Description of the Related Art When a plurality of aquifers are present in the ground, it is necessary to individually pump water from the plurality of aquifers. For example, groundwater contamination survey is performed for each aquifer. In cases such as when investigating the retained thermal energy of groundwater for each aquifer, or when it is necessary to discharge water from a specific aquifer due to ground excavation work, the conventional It was common to have multiple independent wells for each aquifer.

That is, when an upper aquifer 2 and a lower aquifer 3 are present above and below an impermeable layer 1 such as a cohesive soil layer as shown in FIG. Book well 4
And the lower aquifer 3 through the impermeable layer 1
The other wells 5 reaching the above are provided, and the wells 4 and 5 separately pump water from the upper aquifer 2 and the lower aquifer 3. In each of the wells 4 and 5 shown in FIG. 2, reference numeral 6 is a well pipe installed in the excavation hole 7, 8 is a screen formed below the well pipe 6, and 9 is installed in the well pipe 6. The pumping pump 10, 10 is a pumping pipe, 11 is a filter material that fills at least the periphery of the screen 8 in the drill hole 7, and 12 is a filler that closes the upper portion of the drill hole 7. Further, reference numeral 13 in the well 5 is an impermeable zone formed at the position of the impermeable layer 1 in order to prevent groundwater from the upper aquifer 2 from flowing into the well 5.

By the way, as described above, the plurality of wells 4, 5
Independently providing each aquifer 2 and 3 requires not only a high cost but also the wells 4 and 5 cannot be installed so close to each other that sufficient installation space and work space are required. In some cases, this is not preferable, and therefore, it is also considered to adopt a layered pumping apparatus 15 as shown in FIG. 3, for example, to pump water by aquifer by one well.

In the stratified pumping apparatus 15 shown in FIG. 3, screens 16 and 17 corresponding to the upper aquifer 2 and the lower aquifer 3 are vertically arranged in an excavation hole 7 penetrating the impermeable layer 1. The well tube 18 provided in the above is installed, the filter material 11 is filled around each of the screens 16 and 17, and the impermeable zone 13 is formed at the position of the impermeable layer 1. Then, the pumping pump 9 is housed in the casing 19 and arranged at the position of the impermeable layer 1, and the gap between the casing 19 and the well pipe 18 is stopped by the packer 20. An upper valve 21 and a lower valve 22 which are opened and closed by remote control from the surface of the earth are attached to the upper and lower parts.

In this stratified pumping apparatus 15, the upper aquifer 2
Groundwater flows into the well pipe 18 from both the lower aquifer 3 and the filter material 11 and the screens 16 and 17, but by selectively opening and closing the upper valve 21 and the lower valve 22, the aquifer 2 , 3 is used to pump water. That is, the upper valve 21
Open and close the lower valve 22, only groundwater from the upper aquifer 2 will pass through the upper valve 21 and the casing 19
When the upper valve 21 is closed and the lower valve 22 is opened, only groundwater from the lower aquifer 3 flows into the casing 19 through the lower valve 22. It is pumped by the pumping pump 9.

[0007]

By adopting the stratified pumping apparatus 15 as described above, stratified pumping can be performed by one well. However, the stratified pumping apparatus 15 is not limited to the casing 19 and the packer 20. Since it has a complicated and special structure including valves 21, 22, etc., it is costly and time-consuming to manufacture, and there is a problem that installation work on site is not easy.
It has been desired to provide an effective means by which the stratified pumping can be performed more easily.

[0008]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is provided on the ground where a plurality of aquifers are present with an impermeable layer sandwiched between them, and pumps water individually from each aquifer. A stratified pumping well, which forms an excavation hole that penetrates the impermeable layer and reaches an aquifer existing below the impermeable layer, and blocks the interior of the excavation hole at the position of the impermeable layer. A plurality of well pipes that are vertically partitioned by a water belt to reach the position of each aquifer to be pumped and have a screen are formed, with each screen as the position of the aquifer to be pumped. It is characterized in that the pumps are arranged in the drill holes as described above, and pumping pumps are respectively installed in the well pipes.

[0009]

The stratified pumping well according to the present invention does not have a plurality of wells for each aquifer to be pumped as in the conventional case, and does not use a special stratified pumping device. The water is pumped from a single well. That is, in the stratified pumping well of the present invention, by independently providing a drill hole to reach the aquifer of the lowest layer to be pumped,
By partitioning the inside of the drill hole at the position of the impermeable layer into upper and lower parts with a water shield, only the groundwater from the aquifer above the water shield will flow into the hole above the water shield. Also, only the groundwater from the aquifer located below it will flow into the lower part of the impermeable zone. And
Plural well pipes corresponding to each aquifer to be pumped are placed in the drill hole, and groundwater flowing into each well pipe through the screen is pumped individually by the pumps installed in each well pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a schematic structure of a stratified pumping well according to this embodiment. As in FIGS. 2 and 3, reference numeral 1 is an impermeable layer such as a cohesive soil layer, and 2 and 3 are upper portions of the pumping target. The aquifer and the lower aquifer.

The stratified pumping well 30 of this embodiment has a drill hole 31 which penetrates the impermeable layer 1 from the surface of the earth to reach the lower aquifer 3.
While excavating the inside of the excavation hole 31, at the position of the impermeable layer 1, it is partitioned into upper and lower parts by a water shield zone 32 made of, for example, water-blocking concrete, and then two well pipes 33 are provided in the excavation hole 31. , 34 are arranged.

The well pipes 33 and 34 are so long as to reach the upper aquifer 2 and the lower aquifer 3, respectively, and the screens 3 are respectively provided at their lower ends.
5 and 36 are formed, and each screen 3
5, 36 are arranged in the excavation hole 31 so as to be located at the upper aquifer 2 and the lower aquifer 3. Then, in each well pipe 33, 34, the groundwater flowing into the well pipe 33, 34 through the screens 35, 36 is pumped into the pump pipes 37, 3
Pumping pumps 39, 40 for pumping water to the surface through 8
Are installed respectively. In addition, reference numerals 41 and 42 are filter materials filled around the screens 35 and 36, and 4
3 is a backfill layer of generated soil, and 44 is a sand layer.

In the stratified pumping well 30 having the above-mentioned structure, the inside of the excavation hole 31 is vertically divided by the impermeable zone 32, so that the groundwater of the upper aquifer 2 flows into the well pipe 33 from the screen 35. The groundwater of the lower aquifer 3 is pumped by the pumping pump 39, flows into the well pipe 34 from the screen 36, and is pumped by the pumping pump 40. Therefore, although it is a single well, a plurality of aquifers are charged. Layers 2 and 3
It is possible to pump water individually.

In this stratified pumping well 30, two well pipes 33 and 34 are arranged in a single excavation hole 31. Therefore, as shown in FIG. Although it is necessary to increase the diameter of the excavation hole 31 as compared with the case where two independent wells 4 and 5 are provided, the installation space and work space are increased as compared with the case where two wells are independently provided. In addition to saving money, by excavating by exchanging a large excavator used for pile construction, it is possible to reduce the construction cost as a whole. Also, two well tubes 3
3, 34 and two pumping pumps 39, 40 are required, but no complicated and special device is required, and the conventional well tubes 33, 34 can be used as they are. As in the case of using the layered water pumping apparatus 15 as shown, the cost is not high and the production does not take time, and the construction procedure at the site is no different from the conventional procedure.

Since the above embodiment is an example in which the upper aquifer 2 and the lower aquifer 3 are pumped up, the two aquifers 2 corresponding to the upper aquifer 2 and the lower aquifer 3 are taken as examples. Well tube 3
Although only 3, 34 are installed, the same can be applied to the case of pumping a larger number of aquifers. For example, when pumping water from three aquifers that sandwich two impermeable layers, the impermeable belts 3 are respectively placed at the positions of the impermeable layers.
2 is provided to partition the inside of the drill hole 31 into three, and to pump water from each of these three aquifers.
A well tube of a book may be installed in the excavation hole 31. The same applies when pumping more than three aquifers.

[0016]

As described above, the stratified pumping well of the present invention forms a drill hole that penetrates the impermeable layer and reaches the aquifer existing therebelow, and excavates the hole. At the position of the impermeable layer, the hole is divided into upper and lower parts so that water can be blocked by a water shield, and a plurality of well pipes corresponding to each aquifer to be pumped are placed in the excavation hole. It is arranged so that the groundwater of each aquifer that flows into these well pipes is pumped by a pump, so it is possible to use multiple aquifers in spite of being a single well. It is possible to pump water individually, so compared with the case of providing multiple independent wells for each aquifer and the case of using a complicated and special stratified pumping device,
The construction cost can be reduced, and the installation space and work space can be saved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a stratified pumping well that is an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of installation of wells in the case of conventionally pumping water layer by layer.

FIG. 3 is a cross-sectional view showing a conventional example of a layered water pumping device.

[Explanation of symbols]

 1 Impermeable Layer 2 Upper Aquifer (Aquifer) 3 Lower Aquifer (Aquifer) 30 Pumping Well by Layer 31 Drilling Hole 32 Impermeable Zone 33, 34 Well Pipe 35, 36 Screen 39, 40 Pumping Pump .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nakatsuka 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation

Claims (1)

[Claims] 1. A stratified pumping well, which is provided on the ground where a plurality of aquifers are sandwiched between impermeable layers, to individually pump water from each aquifer, said impermeable layer The inside of the excavation hole that penetrates through to reach the aquifer existing below it is partitioned vertically by the impermeable zone at the location of the impermeable layer and the location of each aquifer to be pumped A plurality of well pipes each having a length reaching a length and having a screen are arranged in the excavation hole so that each screen is at the position of the aquifer to be pumped, and a pumping pump is installed in each of the well pipes. A layered pumping device characterized by being installed.