WO2021038925A1

WO2021038925A1 - Pumping well equipped with water injection pipe

Info

Publication number: WO2021038925A1
Application number: PCT/JP2020/008574
Authority: WO
Inventors: 顕治郎本多; 聡西原
Original assignee: 株式会社エーバイシー; 日建商事株式会社
Priority date: 2019-08-29
Filing date: 2020-03-02
Publication date: 2021-03-04
Also published as: JP6667822B1; JP2021032030A

Abstract

The present invention reduces the time and effort needed for installing a water injection pipe when installing a pumping well equipped with the water injection pipe.　A pumping well 100 equipped with a water injection pipe according to the present invention is provided with: a well pipe 1 vertically installed underground and having an underground water inflow hole 1a in a peripheral wall 11; a strainer 2 having a water passing part 21 that is annularly attached to the well pipe 1 and passes underground water; and a pillow member 4 that comprises at least one rod member or a pipe member, which is sandwiched between the outer peripheral surface 11 of the well pipe 1 and the strainer 2 and supports the strainer 2. The pillow member 4 is provided with water injection ports 3a, at least one of which serves as a water injection pipe 3 and injects a liquid.

Description

Pumping well with water injection pipe

The present invention relates to a pumping well for pumping groundwater for the purpose of improving the ground, and particularly to a pumping well provided with a water injection pipe for injecting a liquid into the ground.

In recent years, a liquefaction prevention method that prevents liquefaction by injecting air together with water into the ground where liquefaction is a concern and impregnating the pore water contained between soil particles with air to desaturate the ground. Have been proposed in various ways.
The liquefaction phenomenon of the ground occurs when the soil particle structure is destroyed by the pressure rise of the pore water due to the deformation of the ground, but this method of injecting microbubble water causes the pore water to contain bubbles and cushion the bubbles. This is an attempt to suppress the pressure rise in the pore water.

In such a liquefaction prevention method, since groundwater is pumped up by a pumping well or air and water are injected while pumping up, both the pumping well and the water injection pipe need to be erected underground, and simply pumping water. There was a problem that it took more time than installing a well.

Therefore, although unpublished, the present applicants, in the earlier patent application (Patent Document 1), when injecting fine bubble water into the ground, sand, silica sand, etc. surrounding the well pipe in the pumping well, etc. We are proposing a technology to erect a water injection pipe in a filter material made of water and a technology to use the well pipe itself of a pumping well as a water injection pipe.

Japanese Patent Application No. 2018-225077

However, when the water injection pipe is installed in the filter material, there is a problem that it takes more time to install the water injection pipe than when only the pumping well is installed, and the well pipe itself is used as the water injection pipe. In this case, since the groundwater inflow hole used for injecting fine bubble water is provided only near the lower end of the well pipe, there is a problem that fine bubble water cannot be injected into the ground at a position shallower than this.
The present invention has been made in view of the above problems, and is a liquid for improving the ground (hereinafter, also referred to as "injection liquid") while suppressing the labor required for installing a pumping well and even in a shallow ground. The purpose is to provide a pumping well capable of injecting.).

The invention made to solve the above problems is a well with a water injection pipe provided with a water injection pipe for injecting a liquid into the ground, and is a well pipe that is vertically installed in the ground and has a groundwater inflow hole in the peripheral wall. And a strainer having a water passage portion that is ringed around the well pipe and allows groundwater to pass through, and at least one rod or pipe material that is sandwiched between the outer peripheral surface of the well pipe and the strainer to support the strainer. The pillow material is provided with a water injection port made of, and at least one of the pillow materials also serves as a water injection pipe and is provided with a water injection port for injecting a liquid.

Conventionally, the strainer of a pumping well is ringed around the well pipe using a pipe material or a bar material fixed on the outer circumference of the well pipe as a pillow material. By using this pillow material as a water injection pipe, it is possible to bury the water injection pipe together with the pumping well in the ground without taking more time than installing only the pumping well.

It is preferable that the water injection port injects the injection liquid into the space between the well pipe and the strainer. By doing so, the injection liquid can be injected into the surrounding ground through the gap of the strainer using the space as the distribution chamber, so that the injection liquid can be injected over a wide range.

The pumping well with a water injection pipe of the present invention preferably has a transforming body projecting from the outer peripheral surface of the well pipe in the direction in which the injection liquid is injected from the water injection port. By doing so, the turbulence generated in the space between the well pipe and the strainer can be suppressed, and the injection liquid can be efficiently injected into the ground around the pumping well.

The pumping well with a water injection pipe of the present invention is provided with a plurality of the pillow materials, and two or more pillow materials out of the plurality of pillow materials also serve as water injection pipes, and the two or more water injection pipes are connected at the upper end. It is preferable to have a chamber. By doing so, the injection liquid can be evenly flowed to each water injection pipe.

The distribution room is preferably provided underground. By doing so, it is possible to combine the flow pipes for flowing the injection liquid from the ground to the upper end of the water injection pipe into one, so that the installation cost can be reduced.

The distribution room is preferably provided on the ground surface. By doing so, maintenance of the distribution room can be easily performed.

As described above, according to the pumping well with a water injection pipe of the present invention, it can be installed with the same labor as a conventional pumping well without a water injection pipe, and the injection liquid is ejected even in a shallow ground. can do.

It is a side view sectional view of the pumping well with a water injection pipe which concerns on 1st Embodiment of this invention. It is a partial perspective enlarged view which showed the periphery of the distributor of FIG. 1 in a side view. FIG. 2 is a cross-sectional view taken along line XX in FIG. FIG. 2 is a cross-sectional view taken along the line YY in FIG. FIG. 2A is an explanatory view showing how the injection liquid flows through the distribution chamber by expanding the cylindrical distribution chamber shown in FIG. 2 in a plane. (B) is a sectional view taken along line ZZ in (a), and (c) is a sectional view taken along line WW in (a). It is explanatory drawing which showed the state which the injection liquid is ejected from the water injection pipe of FIG. 1 in a plan view. FIG. 5 is an enlarged cross-sectional view showing the water injection pipe of FIG. 1 in a side view. It is a side view sectional view of the pumping well with a water injection pipe which concerns on 2nd Embodiment of this invention. (A) is an enlarged view of a main part showing the periphery of the distribution chamber of FIG. (B) is a sectional view taken along line VV in (a). A pumping well with a water injection pipe according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, the present invention is not limited to the following embodiments. In addition, the configuration of each embodiment can be appropriately combined with the configuration of other embodiments.
(First Embodiment)
FIG. 1 shows a pumping well 100 with a water injection pipe according to the first embodiment of the present invention. The pumping well 100 with a water injection pipe is a pumping well used in the ultra-deep construction method (registered trademark), and for the purpose of ground improvement such as prevention of liquefaction, pumping groundwater and injecting fine bubble water or the like into the ground. Used to inject W.

As shown in FIG. 1, the pumping well 100 with a water injection pipe includes a well pipe 1 suspended in the ground, a strainer 2 surrounded by the well pipe 1, and one for injecting an injection liquid W into the ground. , Or a plurality of

water injection pipes

3, 3, ..., a pump 5 for pumping the ground water flowing into the well pipe 1, and a distribution for distributing the injection liquid W to the

water injection pipes

3, 3, ... The vessel 6, the pumping pipe 51 for flowing the pumped water to the ground, the well pipe 7 for flowing the injection liquid W to the well pipe 1, and the well pipe 7 and the well pipe 1 were overfilled. It is provided with a return tube 8 that recirculates the injection liquid W.
The well pipe 1 is inserted into a vertical hole vertically laid in the ground, and then erected so as to fill the periphery with a filter material 17 (see FIG. 2) made of sand, silica sand, or the like.

The well pipe 1 is made of a bottomed cylindrical steel pipe, has a flange 16 at the upper end edge, and is closed by a lid material 9. In the well pipe 1, a large number of

groundwater inflow holes

1a, 1a, ... Consisting of circular through holes are dispersedly arranged in the circumferential direction and the longitudinal direction on the peripheral wall located slightly upward from the bottom wall 12. The space 14 from the groundwater inflow hole 1a to the bottom wall 12 constitutes a sand pool. In the illustrated example, the groundwater inflow hole 1a is a circular hole, but the hole is not limited to this and may be a slit or the like. A liquid feeding branch pipe 72 and a return pipe 8 branched from the liquid feeding pipe 7 are connected to the well pipe 1 via a lid material 9.

As shown in FIG. 6, the strainer 2 has a cylindrical coil shape in which a wire rod is wound around a well pipe 1 via a water injection pipe 3 (pillow material 4). The strainer 2 has a slight gap between adjacent wires, and this gap corresponds to the water passage portion 21 as defined in the claims.
The strainer 2 is provided so as to substantially cover the entire portion of the well pipe 1 provided with the groundwater inflow hole 1a, and the uppermost end of the water passage portion 21 is located above the groundwater inflow hole 1a at a sufficient distance from the groundwater inflow hole 1a. Has been done. The space 13 between the strainer 2 and the well pipe 1 is closed above and below by

annular flange members

61 and 22, respectively.
As the strainer 2, for example, a wedge wire having a zinc-plated steel wire having a triangular cross section is used, but the material and shape are not limited to this.

One or more

water injection pipes

3, 3, ... (8 in the example of FIG. 4) are straight pipes as shown in FIG. 1, parallel to the axial direction of the well pipe 1, and the well pipe 1. It is sandwiched between the well pipe 1 and the strainer 2 so as to be parallel to the outer peripheral surface 11 of the well pipe 1 at equal intervals in the circumferential direction of the well pipe 1.
The

water injection pipes

3, 3, ... Also serve as a pillow material 4 that supports the strainer 2 so as to form a space 13 between the outer peripheral surfaces 11 of the well pipe 1. In the illustrated example, all the pillow materials 4 are injected. Although it is a water pipe 3, a pillow material 4 that also serves as a water injection pipe 3 may be provided.

As shown in FIGS. 6 and 7, the injection liquid is to be sprayed onto the peripheral wall 31 of the water injection pipe 3 at equal intervals along the longitudinal direction of the water injection pipe 3 in the substantially circumferential direction of the well pipe 1. A pair of slit-shaped

water injection ports

3a and 3a facing each other are bored. On the outer peripheral surface 11 of the well pipe 1, a rib-shaped transforming body 15 that converts the injection liquid W injected from the water injection port 3a outward in the plan view of the well pipe 1 extends in the longitudinal direction of the well pipe 1. Is provided.

As shown in FIG. 1, the pumping pump 5 is suspended at the lower end of the pumping pipe 51 that hangs down inside the well pipe 1, and draws groundwater that has flowed into the well pipe 1 through the

groundwater inflow holes

1a, 1a, ... It is configured to be pumped and stored in a notch tank (not shown) via a pumping pipe 51, a gate valve 52, and a check valve 53.

In the distributor 6, a flange member 61 is covered with a flat cylindrical lid member 62 and connected with bolts and nuts to form a distribution chamber 63 having a space on an annulus inside. A liquid feeding branch pipe 71 branched from the liquid feeding pipe 7 is connected to the distributor 6 so as to penetrate the top wall of the lid member 62. In the first embodiment, the distributor 6 is provided adjacent to the upper end of the strainer 2 and is buried in the ground. By burying the distributor 6 in the ground in this way, the water injection pipe 3 and the well pipe 1 can be shortened.
However, the shape of the distributor 6 is not limited to this, and an appropriate shape can be adopted. The same applies to the distributor 206 of the second embodiment.

The outlet 71a for flowing the injection liquid from the liquid delivery branch pipe 71 to the distributor 6 is cut diagonally so as to eject the injection liquid W to the downstream side (the side of FIG. 5A) in the circumferential direction of the distributor 6. ing. The inner peripheral surface 62a of the lid member 62 is provided with three types of

conversion plates

64, 65, 66 for evenly distributing the injection liquid W flowing into the distribution chamber 63 from the outlet 71a to each water injection pipe 3. ing.

The conversion plate 64 and the conversion plate 65 are both made of a strip-shaped plate material.
As shown in FIG. 5A, the turning plate 64 is adjacent to each other on the lower half portion of the inner peripheral surface 62a of the lid member 62 in a state of being inclined by approximately 60 degrees with respect to the axial direction of the well pipe 1. It is attached to the inner peripheral surface 62a at a position between the

water injection pipes

3 and 3.
The turning plate 65 is attached so as to extend in the circumferential direction of the inner peripheral surface 62a in the vicinity of the downstream side of the outlet 71a at the upper end of the inner peripheral surface 62a.

The turning plate 66 is made of an isosceles triangular plate material, and is located in the vicinity of the outlet 71a on the upstream side (right side in FIG. 6A) in the circumferential direction of the outlet 71a, and the apex is directed toward the upstream side. It is attached to the inner surface 62b.

(Second Embodiment)
8 and 9 show a pumping well 200 with a water injection pipe according to a second embodiment of the present invention.
The pumping well 200 with a water injection pipe includes a distributor 206 provided on the ground. Along with this, the upper ends of the

water injection pipes

203, 203, ... Extend to the ground. Further, the upper end of the space 13 between the well pipe 1 and the strainer 2 is closed by a flange material 23 separate from the flange material 61. The flange member 23 includes an insertion direction 23a through which the water injection pipe 203 is inserted. In the well pipe 1, the portion 217 surrounding the strainer 2 is filled with a filter material made of sand or silica sand, and the portion between the flange material 23 and the ground surface where the water injection pipe 203 is exposed without being covered by the strainer 2 is formed. The water injection pipe 203 is protected by placing concrete 218.
The water injection pipe 203 also serves as a pillow material 204 that supports the strainer 2.
By providing the distributor 206 on the ground in this way, maintenance of the distributor 206 can be easily performed.

When pumping water using

pumping wells

100 and 200 with a water injection pipe, first, a vacuum pump (not shown) is started to reduce the pressure inside the well pipe 1. Then, the groundwater in the surrounding ground flows into the well pipe 1 through the strainer 2 and the groundwater inflow hole 1a due to the weight of the groundwater and the negative pressure inside the well pipe. When sufficient groundwater has accumulated in the well pipe 1, the pump 5 is started to pump up the groundwater.

Next, when injecting the injection liquid W such as fine bubble water into the surrounding ground, the injection liquid W is sent to the liquid supply pipe 7 by a pressure pump (not shown). Of the injection liquid W fed to the liquid feed pipe 7, a part of the injection liquid W is flowed to the

distributors

6 and 206 via the liquid feed branch pipe 71, and the rest is a well pipe via the liquid feed branch pipe 72. It is sent to the inside of 1.

The injection liquid W sent to the

distributors

6, 206 flows into the distribution chamber 63 from the outlet 71a of the liquid delivery branch pipe 71, and is guided by the turning

plates

64, 65, 66, and each water injection pipe 3,203. It is evenly sent to. Here, the diversion plate 65 guides the injection liquid W to circulate in the annular distribution chamber 63, and the diversion plate 64 guides the injection liquid W to circulate in the distribution chamber 63 to the water injection pipes 3,203. Guidance to flow in. Further, the conversion plate 66 avoids the turbulent flow generated when the circulating injection liquid W collides with the liquid supply branch pipe 71.

The injection liquid W sent to the

water injection pipes

3 and 203 is injected from the water injection port 3a into the space 13 between the well pipe 1 and the strainer 2, and is converted outward by the transforming body 15 to the surrounding ground. Is injected into. As shown in FIG. 6, since the transforming body 15 is provided between the adjacent

water injection pipes

3 and 3, the injection liquid injected from the

water injection ports

3a and 3a of the adjacent

water injection pipes

3 and 3 is provided. It is possible to prevent W from interfering with each other.

On the other hand, the injection liquid W sent into the well pipe 1 is injected into the surrounding ground from the

groundwater inflow holes

1a, 1a, ... And the water passage portion 21 of the strainer 2. Of the injection liquid W sent into the well pipe 1, the surplus injection liquid W is refluxed via the return pipe 8.

The pumping

wells

100 and 200 with water injection pipes can be installed without requiring new man-hours for providing the water injection pipes because the

pillow materials

4, 204 supporting the strainer 2 also serve as the water injection pipes 3,203.

Further, since the pumping

wells

100 and 200 with water injection pipes are provided with

distributors

6 and 206 for distributing the injection liquid W to the plurality of water injection pipes 3,203, the injection liquid W is evenly distributed to the water injection pipes 3,203. Can be infused.

The present invention is not limited to the above-described embodiment, and any pumping well provided with a strainer may be used, and a vacuum pump for depressurizing the inside of the well pipe may not be provided. Further, the present invention does not have to be configured to inject the injection liquid W into the ground through the groundwater inflow hole of the well pipe.

Alternatively, as in the pumping well 300 with a water injection pipe shown in FIG. 10, only one water injection pipe is sufficient, and water is supplied to the water injection pipe directly from the water injection pipe 303 (pillow material) without going through a distributor. You may go to 304). The strainer is not limited to a coil-shaped strainer wound with a wire rod, but may be a through hole provided in a plate material such as a punching board as a water passage portion. In this case, a water injection pipe and a pillow material are wound around a well pipe. It may be composed of one pipe material.

The injection liquid is not limited to the one that injects fine bubble water, mixed water of air and water, liquid containing ground improvement materials such as ground solidifying material, etc. for the purpose of preventing liquefaction, but also ground subsidence due to pumping work. For the purpose of preventing the depletion of well water, it may simply recirculate groundwater.

100,200,300 Pumping well with water injection pipe 1 Well pipe 11 Outer surface 15 Transforming body 2 Strainer 21 Water flow part 3,203,303 Water injection pipe 3a Water injection port 31 Peripheral wall of water injection pipe 4,204,304

Pillow material

6, 206 distribution room

Claims

A pumping well with a water injection pipe equipped with a water injection pipe that injects liquid into the ground.
A well pipe that is laid underground and has a groundwater inflow hole in the peripheral wall,
A strainer that is ringed around the well pipe and has a water passage for groundwater.
A pillow material made of at least one bar or a pipe material sandwiched between the outer peripheral surface of the well pipe and the strainer to support the strainer is provided.
The pillow material is a pumping well with a water injection pipe, characterized in that at least one of the pillow materials also serves as a water injection pipe and has a water injection port for injecting a liquid.
The pumping well with a water injection pipe according to claim 1, wherein the water injection port injects a liquid into the space between the well pipe and the strainer.
The pumping well with a water injection pipe according to claim 2, which has a transforming body projecting from the outer peripheral surface of the well pipe in the direction in which the liquid is injected from the water injection port.
A plurality of the pillow materials are provided, and two or more pillow materials out of the plurality of pillow materials also serve as water injection pipes.
The pumping well with a water injection pipe according to any one of claims 1 to 3, which has a distribution chamber for connecting the two or more water injection pipes at the upper end.
The pumping well with a water injection pipe according to claim 4, wherein the distribution room is provided underground.
The pumping well with a water injection pipe according to claim 4, wherein the distribution room is provided on the surface of the earth.