JPH07247553A - Underground water lift - Google Patents

Abstract

PURPOSE:To lift a high head underground water by use of a simple structure with a self-jetting function. CONSTITUTION:A supply pipe 8 is contained in a casing 1 in which a strainer 2 is formed at a specified position to supply pressure water to the front end 8a of the pipe on excavating the ground and supply compressed air to the front end 8a of the pipe on lifting water. And a boring point 3 for jetting pressure water toward the ground through specified openings formed on the surface on excavation and sucking the sorrounding underground water into the casing 1 on lifting, is connected at the front end of the casing 1. And it is buried in the ground by self-jetting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groundwater pumping device,
In particular, the present invention relates to a groundwater pumping apparatus having a self-jetting function and capable of pumping groundwater with a high head.

[0002]

2. Description of the Related Art Conventionally, in the ground where the groundwater level is high, when excavating the ground to a position deeper than the groundwater level, various drainage methods and water stoppage methods have been adopted to prevent the influence of the groundwater. Among them, the well-point construction method, in which the groundwater is continuously pumped up by vacuum suction, is widely adopted. In this well point construction method, groundwater is first sucked by a vacuum pump on the ground through a riser pipe using a well point buried in the ground as a suction port. As a result, an unequal pressure (negative pressure) is generated between the atmospheric pressure acting on the water table and the vacuum inside the riser pipe. Then, the suction is performed by utilizing the water level change that occurs so as to cancel this unequal pressure. Therefore, the suction height of groundwater is theoretically H =
Although it can be expected to be 10.3 m, it is practically designed with a lift of up to about 6 m (the distance between the well point center and the vacuum pump axial center).

Well points are also often employed to reduce the groundwater level in excavated areas that have a certain extent. Therefore, usually, a plurality of well points are arranged at predetermined intervals on the outer circumference of the excavation area or the like.
The groundwater pumped up to the ground through each riser pipe is connected to a header pipe laid so as to cover the aboveground position of each well point to collect water, and is drained by a drainage pump installed at a predetermined location of this header pipe. It is supposed to be done.

[0004]

However, at the well point described above, the depth of water drop per water is limited to about 6 m. Therefore, when the excavation depth is deep, while excavating, there are 2 stages, 3 stages. It was necessary to reduce the groundwater level by the multi-stage well point construction method, in which well points were sequentially installed in stages.

In addition, since the groundwater is pumped up by vacuum suction in the well point construction method, it is necessary to secure a predetermined degree of vacuum in the entire equipment of the well point, riser pipe, header pipe and drainage pump. Therefore, even if a part of the well points sucks in air, the vacuum degree may be lowered due to the suction. Furthermore, since each well point connects the riser pipe to the header pipe via the swing hose, there are many connection points on the ground. Since it is expected that air will be sucked into each of the parts, there is a problem in that maintenance and management of the entire facility will be a major task.

Further, the well point was driven by jetting in which high-pressure water sent through the riser pipe was jetted from the tip to make a hole. However, in the case of an apparatus capable of solving the above problems, self-jetting is performed. It is desired to have a starting function.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide a groundwater pumping apparatus having a self-jetting function, a simple structure, and capable of pumping groundwater of high head. To provide.

[0008]

To achieve the above object, the present invention provides a casing in which a strainer is formed at a predetermined position and is embedded in the ground, and a pipe for supplying pressure water when the ground is drilled in the casing. A supply pipe that supplies compressed air to the tip of the pipe when supplying water to the tip, and is connected to the tip of the casing and has a predetermined opening formed on the surface through which pressure water is directed to the ground during drilling. It is provided with a drilling point capable of injecting water into the casing and injecting the surrounding groundwater into the casing during pumping.

In this case, the lower end of the supply pipe is supported by a part of the drilling point and communicates with the drilling point at the time of ground drilling, and is separated from the drilling point at the time of pumping water, and inside the casing. It is preferable to use the compressed air as the jet port.

[0010]

According to the present invention, in the casing in which the strainer is formed at the predetermined position, the pressure water is supplied to the pipe tip at the time of ground drilling, and the compressed air is supplied to the pipe tip at the time of pumping. At the tip of this casing, a predetermined opening is formed on the surface, pressure water is jetted toward the ground at the time of drilling through the opening, and a drilling point that allows surrounding groundwater to flow into the casing at the time of pumping is connected. Since it is buried in the ground by self-jetting, it is easy to install in the ground and the groundwater in the casing is pushed up in a lump as the compressed air sent through the supply pipe rises. In this way, it is possible to ascend and drain it above the ground even at high heads.

In this case, the lower end of the supply pipe is supported at a part of the drilling point at the time of ground drilling, communicated with the drilling point, and the pressure water is jetted from the opening of the drilling point to surround the surrounding area. Drilling can be performed while loosening the ground, and the lower end is separated from the drilling point by pulling up the supply pipe when pumping water, so that the compressed air is jetted out in the casing. Is performed efficiently, and the groundwater in the casing is entrained in the compressed air and is reliably discharged to the ground.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a groundwater pumping system according to the present invention will be described below with reference to the drawings. FIG. 1A shows a state in which the ground is pumped by the groundwater pumping apparatus according to the present invention, and a part thereof is cut away so that the self-jetting operation becomes clear. In the figure, reference numeral 1 indicates a casing. In this embodiment, the casing 1 is manufactured to have a length of 1 to 3 m and a diameter of 30 to 80 mm. It is designed to be connected to each other on the ground and set up to a predetermined depth. A strainer 2 having substantially the same diameter is firmly connected to the lower end of the casing 1 so as not to come off. This strainer 2 is a metal strainer 2 having a predetermined opening ratio.
The opening ratio is set so as not to cause clogging when groundwater flows into the strainer 2. The opening ratio (size) that does not cause this clogging is preferably about 50 to 80% of the residual particle size of the filter F formed around the casing 1. The strainer 2 may be of various types such as a flat-fold wire mesh, a wire-wound type, punching metal, and a vertically elongated slot.

Further, a drilling point 3 is attached to the lower end 2a of the strainer 2. This drilling point 3 is shown in Fig. 3.
As shown in the cross section, a conical tip portion 3A and a cylindrical portion 3B that houses a supply pipe holder 4 (described later) therein.
The diameter of the cylindrical portion 3B is set to be substantially the same as the diameter of the casing 1. And the conical tip 3A
A plurality of oval-shaped openings 5 are formed in the. As will be described later, the opening 5 is designed so that pressure water is jetted toward the ground at the time of boring, and functions as a jet water jet port for boring a well hole. It also functions as an inlet for the groundwater around the casing into the casing during pumping.

In the pumping apparatus having the above structure,
The installation location of the strainer 2 is not limited to the lower end of the casing 1 as shown in FIG. 1. For example, in the case where the aquifer and the impermeable layer are alternate layers, the strainer 2 and the casing 1 are set to predetermined positions. It is also preferable that the pumping apparatus is installed alternately with a space of, and the shape of the entire pumping device is determined so that the strainer 2 is arranged corresponding to the depth position of the aquifer.

On the other hand, a supply pipe 8 is housed inside the pumping device having an outer shell portion formed by the casing 1 and the strainer 2, and extends along the longitudinal direction of the pumping device from the drilling point 3 position at the lower end to the ground. It has been extended to the department. Therefore, the pumping device has a double pipe structure as a whole. The lower end of the supply pipe 8 is fitted into the cylindrical holder 6 of the supply pipe holder 4 shown in FIGS. 1A and 3A, and at a predetermined position in the casing 1, the position is almost fixed by the spacer 7. It is held so as to be placed at the center position of the, and its upper end extends to the ground portion. In this embodiment, a pressure-resistant hose is used in the present embodiment, in which a cylindrical core formed by braiding synthetic fibers in order to withstand the internal pressure of drilling water passing through the inside of the supply pipe 8 is coated with resin on both sides. ing. As the coating resin, various thermoplastic resins such as vinyl chloride and polyethylene can be used. In addition, a pressure-resistant rubber hose, a flexible metal hose, or the like can be used.

The role of the supply pipe 8 during drilling and pumping will be described. At the time of drilling, this supply pipe 8 plays a role of sending drilling pressure water for drilling a well hole. Therefore, a high pressure pump (not shown) for supplying pressurized water is connected to the upper end of the supply pipe 8. The drilling pressure water (jet water) sent from the high-pressure pump is sent to the lower end 8a of the supply pipe supported by the cylindrical holder 6, and further, from the plurality of openings 5 formed on the surface of the drilling point 3 to the ground. It is ejected toward (Fig. 1 (a),
See FIG. 3 (a) arrow). At this time, the water pressure of the jet water ejected from the opening 5 is set to a high pressure so as to sufficiently loosen the surrounding ground such as sandy ground, so that the drilling point 3 can easily penetrate into the loose ground. it can. Then, in accordance with the penetration of the drilling point 3, the casing 1 can be sequentially connected at the above-ground portion to form a well hole in which the entire pumping device can be buried. That is, the water pumping device according to the present invention has an advantage that it has a self-jetting function and can form a well portion in which the water pumping device can be installed without requiring a boring machine or other boring machine.

Next, the casing 1 and the portion of the supply pipe 8 (hereinafter referred to as the well portion W) installed in the well hole are connected to the well portion W at the above-ground portion so as to be used as a part of the pumping apparatus. The equipment for pumping and draining will be explained.
FIG. 2 is an explanatory diagram showing the entire pumping equipment. In the figure, the well portion W of the pumping device is already buried up to a predetermined depth, and the drain hose 10 and the air supply hose 11 are provided at the upper end thereof.
Is shown connected. A drain hose 10 having the same diameter is connected to an upper end 1b of the casing 1 of the well portion W via a connector (not shown), and the other end of the drain hose 10 extends to a drain tank 12 installed on the ground. The groundwater pumped up is temporarily stored in the drainage tank 12. Similarly, an air supply hose 11 is connected to the upper end 8b of the supply pipe 8 located in the casing 1, and the other end of the air supply hose 11 is connected to a compressor 13 which is a pressure source of compressed air. Even in the above-ground part, the air supply hose 11 is the drain hose 10
It is housed inside and has a double pipe structure as a whole. The air supply hose 11 is the end portion 10a of the drain hose 10.
And is further connected to the above-mentioned compressor 13.

Further, the supply pipe 8 connected to the air supply hose 11 is pulled up in the casing 1 by a predetermined height (in this embodiment, set to about 50 cm) from the installation position at the time of drilling. The lower end of the supply pipe 8 is separated from the holder so that a clearance is provided between the cylindrical holder 6 and the lower end 8a of the supply pipe (FIGS. 1 (b) and 3 (b)).
reference).

Next, the operation of sending compressed air A from the compressor 13 through the air supply hose 11 and the supply pipe 8 and ejecting it from the lower end 8a of the supply pipe to pump up groundwater will be described. The groundwater level in the casing before the start of pumping is
Since groundwater flows into the casing from the strainer 2 portion of the well portion W, the water level is equal to the surrounding ground water level. At this time, the lower end 8a of the supply pipe is submerged below the groundwater level. In this state, the compressor 13 is started, the compressed air A is sent to the supply pipe 8 in the casing 1, and the compressed air A is ejected from the lower end 8a of the supply pipe into the casing 1 (Fig. 1 (b), Fig. 3 ( See b)). When the compressed air A is vigorously ejected into the casing 1, the groundwater sandwiched between the supply pipe 8 and the casing 1 is pushed up by the compressed air A and rises so as to be lumped and jumped. At the beginning of insufflation, only the compressed air A pushing up the water mass rises so as to break the water mass, but the compressed air A is continuously supplied from the lower end 8a of the supply pipe into the casing 1. There is. Therefore, the water mass gradually pushes up in the casing 1 and the volume increases. Then, the water mass pushed up to a high position in the casing 1 has a certain volume or more, is pushed up to the ground all at once, and is drained to the drainage tank 12 through the drainage hose 10 on the ground. As a result, the water in the casing 1 is intermittently pumped to the ground with a high head. In this way, it is possible to realize a lowered water level surface up to a deeper head (: L) than the conventional well point method (see FIG. 2).

At this time, the pressure of the compressed air A supplied from the compressor 13 on the ground is initially set to be equal to or higher than the head difference between the groundwater level and the lower end 8a of the supply pipe, and the compressed air A is pressurized at once. It can be jetted from the lower end of the supply pipe 8 and can rise in the space formed between the casing 1 and the supply pipe 8. Therefore, by providing a circuit that detects the groundwater level in the ground and controls the output of the compressor 13 according to the groundwater level, the compressor 13
It is also possible to drive the car in the optimum state.

In this embodiment, as shown in FIGS. 1 and 2, a predetermined gap is formed between the hole wall of the well hole formed by jetting and the buried casing 1. And this part is filled with filter sand,
A filter layer F that promotes the inflow of groundwater is formed. As a result, the effect of collecting water in the pumping device can be further enhanced. Also, in the case of the ground where there is no risk of the hole wall collapsing,
The casing 1 for preventing the collapse of the hole wall can be omitted. In such a case, a resin-made hose having pressure resistance may be used instead of the steel casing 1. In this case, first, when the drilling of the well hole by the casing 1 is completed, the casing 1 is once pulled up, and the drilling point 3 used as a water collecting pipe is attached to the tip of the resin hose to attach the well portion of the pumping device. W may be configured. Then, this well portion W can be used again by inserting it into the well hole. In this case, the pumping device has a structure in which it is suspended in the well, but since its own weight is small, a simple supporting structure is sufficient.

In the above description, an example of a one-stage pumping system has been described. However, when it is necessary to lower the groundwater level beyond the limit pump head of this pumping system, this pumping system is arranged in multiple stages. Is also good. In this case, according to the present invention, unlike the Well Point method, header pipes are not installed in multiple stages, and it is possible to reduce the groundwater level in multiple stages with simple equipment.

[0023]

As is apparent from the above description, according to the present invention, it is easy to install in the ground, and it is possible to pump up groundwater with a high head by a simple above-ground facility. It is possible to improve work efficiency and reduce equipment costs.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view showing an embodiment of a groundwater pumping device according to the present invention.

FIG. 2 is a schematic equipment configuration diagram showing an example of a groundwater pumping apparatus of the present invention.

FIG. 3 is a partial cross-sectional view showing an operating state during drilling and pumping of the tip portion of the groundwater pumping apparatus shown in FIG.

[Explanation of symbols]

 1 Casing 2 Strainer 3 Drilling point 4 Supply pipe holder 5 Opening 8 Supply pipe 10 Drain hose 11 Air supply hose 13 Compressor

Claims (2)

[Claims] 1. A casing in which a strainer is formed at a predetermined position and buried in the ground, pressure water is supplied to the pipe tip at the time of ground drilling, and compressed air is supplied to the pipe tip at the time of pumping. Connected to the supply pipe and the tip of the casing, a predetermined opening is formed on the surface, through which the pressure water is jetted toward the ground at the time of drilling, and the surrounding groundwater can flow into the casing at the time of pumping. A groundwater pumping device characterized by having various drilling points. 2. A lower end of the supply pipe is supported by a part of the drilling point and communicates with the drilling point at the time of ground drilling, and is separated from the drilling point at the time of pumping water, and is separated from the drilling point in the casing. The groundwater pumping apparatus according to claim 1, wherein the groundwater pumping apparatus serves as a jet of compressed air.