JP7589938B2 - Underground drainage device and underground drainage structure - Google Patents

Description

The present invention relates to an underground drainage device and an underground drainage structure that can smoothly drain groundwater without clogging due to particles such as soil and sand.

For example, Patent Documents 1 and 2 are known as technologies for draining groundwater that has seeped into the ground. The "drainage pipe" in Patent Document 1 is a drainage pipe that is buried underground to drain water that has seeped into the ground, and is configured with numerous slit-shaped water passage holes that extend in the axial direction on the circumferential surface.

The "underground water collection pipe" of Patent Document 2 aims to provide a water collection pipe that is less likely to clog and is easy to manufacture with low manufacturing costs, and is made of a perforated plate with an opening ratio of 5 to 50%.

Japanese Utility Model Application Publication No. 4-37624 JP 2003-232028 A

Groundwater that seeps into the earth is cloudy because it is mixed with particles such as soil and sand. Some of these particles float in the water, but they are heavier than water and sink.

The background art aims to drain water from the soil without clogging the holes by adjusting the shape, number and opening ratio of the holes.

However, when groundwater flows into drainage pipes or collection pipes, it is inevitable that the holes will be blocked by particles such as soil and sand that flow in along with the groundwater, causing clogging. In addition, the weight of the particles that flow into the inside of the drainage pipes causes them to settle and accumulate inside the pipes, causing the drainage pipes themselves to become clogged, and they are unable to continue to perform their functions of drainage and collection.

The present invention was devised in consideration of the above-mentioned problems with the conventional technology, and aims to provide an underground drainage device and an underground drainage structure that can smoothly drain groundwater without clogging due to particles such as soil and sand.

The underground drainage device of the present invention is an underground drainage device for draining groundwater that has infiltrated into the ground, and is equipped with a hollow pipe material and a hollow cylindrical connecting pipe that connects the pipe materials together, the connecting pipe having a first connecting part at one end in the pipe axis direction into which the pipe material is inserted and connected, and a second connecting part at the other end in the pipe axis direction into which another pipe material is inserted and connected, and the first connecting part has a flow path formed between the first connecting part and the pipe material, the flow path having an inlet that opens toward the ground outside the connecting pipe, for connecting the inside of the pipe material to the ground.

The flow path is characterized in that at least one is formed in the first connection part.

The first connection part has a groove-shaped portion formed by partially increasing the inner diameter of the first connection part, and the flow path is formed between the groove-shaped portion and the pipe material.

The connecting pipe is characterized in that an internal partition is formed to separate the first connecting portion from the second connecting portion, and the internal partition is formed with a through hole that communicates the insides of the pipe materials connected to the connecting pipe.

The pipe material has a thread formed on the outer periphery, and the first and second connection parts of the connecting pipe have a thread groove formed on the inner periphery, and the two pipe materials are screwed into the first and second connection parts, respectively.

The drilling bit has a connection part into which the pipe material is inserted and connected, and the connection part has a bit part flow passage formed between the connection part and the pipe material to connect the inside of the pipe material to the ground outside the drilling bit.

The underground drainage structure of the present invention uses the above-mentioned underground drainage tool, which is inserted into the ground with the inlet of the flow path and the pipe facing diagonally downward, and is positioned so that the diagonally downward tip of the pipe is exposed from the ground to the ground surface as the insertion end.

The underground drainage device and underground drainage structure of the present invention can smoothly drain groundwater without clogging due to granular particles such as soil and sand.

1 is an explanatory diagram illustrating a preferred embodiment of an underground drainage device and an underground drainage structure according to the present invention. FIG. FIG. 2 is a perspective view of a main portion of the underground drainage device shown in FIG. 1 . 2A to 2C are diagrams illustrating the underground drainage device shown in FIG. 1, in which (A) is a side view, (B) is a plan view, and (C) is a partially cutaway side view. FIG. 2 is a side cross-sectional view of the connecting pipe of the underground drainage device shown in FIG. 1 . 4A and 4B are views of the underground drainage device shown in FIG. 1 as viewed from the direction of the arrows A-A in FIG. 4, in which (A) shows the state before the pipe material is inserted, and (B) shows the state after the pipe material has been inserted. 2 is an explanatory diagram for explaining the operation of the underground drainage device and the underground drainage structure shown in FIG. 1 . FIG. 2 is a side cross-sectional view of a cover attached to the underground drainage device shown in FIG. 1 and cut along a cutting line. FIG. 2 is a side cross-sectional view of a main portion of a modified example of a self-drilling bit provided in the underground drainage tool shown in FIG. 1 . 9A and 9B are diagrams illustrating a modified example of the underground drainage device according to the above embodiment, in which (A) is an explanatory diagram showing the underground drainage device with the connecting pipe portion in cross section, and (B) is a cross-sectional view taken along line D-D in FIG. 9A.

Below, a preferred embodiment of the underground drainage device and underground drainage structure of the present invention will be described in detail with reference to the attached drawings.

The underground drainage device 1 according to this embodiment is basically constructed by connecting two pipes 2, 3 with one connecting pipe 4 in the longitudinal direction (also called the pipe axis direction) of the pipes 2, 3, as shown in FIG. 1, and is designed to drain groundwater w that has infiltrated into the ground E.

The underground drainage device 1 is used by being inserted into the ground E, and a self-drilling bit 5 is provided at the end of the pipe material 3 which is the insertion tip of the underground drainage device 1, and the self-drilling bit 5 is rotated around the pipe axis C by a motor to penetrate into the ground E, and the end of the pipe material 2 which is the rear end of the underground drainage device 1 is positioned so that it is exposed from the ground E to the ground surface G, thereby forming the underground drainage structure 6 according to this embodiment.

In the illustrated example, an underground drainage device 1 is shown that is composed of two pipes 2, 3 and one connecting pipe 4, but the underground drainage device 1 may also be configured to be long, with multiple pipes 2, 3 connected in the longitudinal direction of the pipes 2, 3 by multiple connecting pipes 4, with the pipes 2, 3 being successively joined by the connecting pipes 4.

In addition, the underground drainage device 1 does not necessarily require a self-drilling bit 5, and may be inserted into a pre-boring hole formed toward the ground E.

As shown in Figures 1 to 5, the pipes 2 and 3 constituting the underground drainage device 1 according to this embodiment have the same dimensions (although the lengths may differ), and are hollow inside, with a hollow passage 7 formed continuously from one end to the other in the length direction for circulating groundwater w.

The pipes 2 and 3 are, for example, metal rock bolts such as steel or hollow PVC pipes made of hard resin such as polyvinyl chloride. In the case of rock bolts, the outer circumference of the pipes 2 and 3 is formed with a thread 8.

The connecting pipe 4, like the pipe materials 2 and 3, is made of metal or hard resin and is formed into a hollow cylinder from one end to the other in the length direction (also called the pipe axis direction).

As shown in Figures 3 and 4, the connecting pipe 4 has an internal partition 13 (described later) integrally formed inside the hollow cylinder, and has a cylindrical first connecting portion 10 at one end of the length from the internal partition 13 into which one of the two pipes 2, 3 is inserted and connected, and a cylindrical second connecting portion 11 at the other end of the length into which the other pipe 3 is inserted and connected.

A screw groove 12 is formed on the inner circumference of the first and second connection parts 10, 11, and the threads 8 of the two pipe materials 2, 3 are screwed into the screw grooves 12 of the connection parts 10, 11, so that the two pipe materials 2, 3 inserted from both ends of the length of the connection pipe 4 are connected to each other by the connection pipe 4.

A wall-like internal partition 13 is integrally formed within the connection pipe 4 to separate the first connection part 10 and the second connection part 11.

The thread groove 12 of the second connection part 11 is formed so that the pipe material 3 inserted into the second connection part 11 abuts against the internal partition 13 and reaches the internal partition 13. Therefore, in the second connection part 11, the internal partition 13 functions as a stopper that regulates the insertion amount of the pipe material 3 to be screwed.

On the other hand, the thread groove 12 of the first connection part 10 is formed to a position spaced apart from the internal partition 13 so that the pipe material 2 inserted into the first connection part 10 forms a gap S between the pipe material 2 and the internal partition 13.

The internal partition 13 is provided with a through hole 14 that penetrates from the first connection part 10 to the second connection part 11 to connect the hollow passages 7 of the two pipes 2, 3 connected to the first and second connection parts 10, 11 and allows groundwater w to flow between the pipes 2, 3. The gap S also communicates with the hollow passage 7 of the pipe 2 inserted into the first connection part 10.

As shown in Figures 3 to 5, the first connection part 10 has a flow path 15 formed between the inner surface of the first connection part 10 and the outer surface of the pipe material 2 inserted into the first connection part 10, for connecting the hollow passage 7 of the pipe material 2 to the outside of the underground drainage device 1, i.e., to the ground E into which the underground drainage device 1 is inserted.

The flow path 15 has an inlet 16 that opens toward the ground E outside the connecting pipe 4 at the end of the connecting pipe 4 opposite the internal partition 13 in the longitudinal direction of the first connecting part 10 (the longitudinal direction of the connecting pipe 4).

The flow path 15 is also connected to the gap S on the side of the internal partition 13. As a result, at the first connection part 10, the inlet 16 is connected to the flow path 15, the gap S, and the hollow passage 7 of the pipe material 2.

In this embodiment, the inner diameter of the first connection part 10 is partially increased at an appropriate circumferential position on the inner surface of the first connection part 10 from the longitudinal end of the connection pipe 4 along the longitudinal direction of the first connection part 10 to form a groove-like groove portion 17, and this groove portion 17 forms a flow path 15 between the inner surface of the first connection part 10 and the outer surface (thread thread 8) of the pipe material 2.

Figure 5 is a view seen from the direction of the arrow A-A in Figure 4, where (A) shows the state before the pipe material 2 is inserted, and (B) shows the state after the pipe material 2 is inserted. The groove-like portion 17 on the inner surface of the first connection part 10 is formed with a curved surface of a concave line that allows groundwater w to flow smoothly in the circumferential direction of the first connection part 10, and no screw groove 12 is formed in the groove-like portion 17. In other words, in the first connection part 10, the pipe material 2 is screwed into the screw groove 12 at a position other than the groove-like portion 17.

As shown in Figures 2 to 5, at the location where the groove-shaped portion 17 is formed, a convex portion 18 is formed that bulges out from the outer surface of the first connecting portion 10 of the connecting pipe 4 in order to process and mold the flow path 15 and ensure the thickness of the entire connecting pipe 4.

In this embodiment, the flow paths 15 are formed at two locations facing each other in the diameter direction of the first connection part 10.

However, it is sufficient to form at least one flow path 15, or three or more may be provided at appropriate intervals around the circumference of the first connection part 10.

By using the underground drainage device 1 according to this embodiment and inserting it into the ground E, an underground drainage structure 6 according to this embodiment is formed, as shown in Figure 1.

The underground drainage device 1 is inserted into the ground E while drilling a hole in the ground E with the self-drilling bit 5 attached to the end of the pipe material 3, which serves as the insertion tip.

At this time, the drilling is performed diagonally upwards with the self-drilling bit 5 relative to the horizontal at the insertion point underground E, and the underground drainage device 1 is inserted in a position in which the inlet 16 of the connecting pipe 4 and the pipe materials 2, 3 connected by the connecting pipe 4 (their pipe axial directions) are facing diagonally downwards (see "Tilt angle" in Figure 1).

Then, the end of the pipe material 2 facing diagonally downward (the hollow passage 7 opens diagonally downward) located diagonally downward on the opposite side to the insertion end located diagonally upward in the ground E is positioned so as to be exposed from the ground E to the ground surface G as the insertion termination point, in order to connect the hollow passage 7 to the outside of the ground surface G.

As shown in Figure 1, the end of the pipe material 2, which is the insertion end, is fitted with a cover 19 that can be easily machined, such as made of polyvinyl chloride, and is screwed onto the thread 8 so that it extends from the end. As shown in Figure 7, this cover 19 is cut out along the cut surface along the ground surface G so that the insertion end does not appear as a protrusion on the ground surface G.

The function of the underground drainage device 1 and the underground drainage structure 6 according to this embodiment will be explained.

First, the installation and construction of the underground drainage device 1 will be explained. When burying the underground drainage device 1 in the ground E, a motor is attached to the leading pipe material 3 equipped with the self-drilling bit 5, and drilling work is started diagonally upward from the ground surface G toward the ground E. When the pipe material 3 protrudes diagonally downward from the ground surface G, drilling is temporarily stopped, the motor is removed from the pipe material 3, and then the second connection part 11 of the connecting pipe 4 is connected to the pipe material 3, and the pipe material 2 is connected to the first connection part 10 of the connecting pipe 4. Therefore, the inlet 16 of the flow path 15 of the connecting pipe 4 is oriented diagonally downward.

A motor is attached to the pipe material 2 connected to the first connection part 10, and further drilling work is performed. When multiple pipe materials 2, 3 are to be joined using multiple connection pipes 4, the above work is repeated.

As a result, the underground drainage device 1 of the required length is inserted into the ground E with the inlet 16 and the pipe materials 2 and 3 facing diagonally downward.

At the end of the drilling operation, a cover 19 is attached to the end of the pipe material 2, which is the insertion termination point of the underground drainage device 1 that has been buried in the ground E up to near the ground surface G where drilling began, and this cover 19 is cut to fit the ground surface G, so that the underground drainage device 1 is positioned so that it is exposed to the ground surface G. In this way, construction of the underground drainage structure 6 with the underground drainage device 1 inserted into the ground E is completed.

Next, we will explain how to drain groundwater w using the underground drainage device 1.

As the water pressure underground E increases, groundwater W carrying particles such as soil and sand moves toward the void.

The flow path 15 having the inlet 16 of the underground drainage device 1 according to this embodiment is a void in the ground, into which groundwater w flows along with granular matter such as soil and sand, as shown in FIG. 6. Also, if there is granular matter such as soil and sand in the inlet 16 or flow path 15, the groundwater w in the vicinity is guided to the flow path 15 by capillary action.

When the underground drainage device 1 is inserted into the ground E, the inlet 16 of the connecting pipe 4 faces diagonally downward, and the flow path 15 also faces diagonally downward. Therefore, the groundwater w containing particles such as soil and sand that flows into the flow path 15 from the inlet 16 settles from the flow path 15 to the ground E side, and remains there. On the other hand, although the groundwater w contains suspended matter, it overflows from the upper end of the flow path 15 as the supernatant and flows through the gap S into the hollow passage 7 of the pipe material 2.

The pipes 2 and 3 are inserted diagonally downward so that groundwater w flows naturally from a higher point to a lower point toward the ground surface G. The groundwater w that flows in passes through the hollow passage 7 of the pipes 2 and 3 and is discharged toward the ground surface G from the cover 19 at the end of the insertion.

As a result, the underground drainage device 1 according to this embodiment can smoothly and efficiently drain groundwater w from underground E without clogging due to granular particles such as soil and sand.

When multiple pipes 2, 3 are connected by multiple connecting pipes 4, groundwater w flows into each connecting pipe 4 in the same way and flows down the hollow passages 7 of the pipes 2, 3, and then flows down the hollow passages 7 of the pipes 2, 3 while merging through the through holes 14 of the internal partitions 13 at each of the connecting parts 4 located successively lower, as shown in Figure 6.

This allows the groundwater w at the insertion point of the underground drainage device 1 and its surrounding area to be drained from the ground E.

In this embodiment, the pipe materials 2 and 3 are rock bolts, so the ground can be reinforced. The hole into which the underground drainage device 1 is inserted is formed with a self-drilling bit 5, so drilling and installing the underground drainage device 1 can be performed simultaneously, ensuring high construction efficiency and allowing smooth construction even in narrow spaces compared to, for example, pre-boring with a boring machine.

Because the pipe materials 2 and 3 are rock bolts, the underground drainage device 1 according to this embodiment can be inserted into existing drainage equipment in which polyvinyl chloride pipes or the like are inserted and buried, making it possible to repair equipment with reduced drainage function.

Figure 8 shows a modified example of a self-drilling bit 5 that drills holes to insert the underground drainage device 1 into the ground E.

In this modified self-drilling bit 5, the connection part 20 for inserting and connecting the pipe material 3 leading in the insertion direction has the same structure as the first connection part 10 of the connecting pipe 4, except for the through hole 14. In other words, as described above, a bit part flow path 21 is formed between the inner surface of the connection part 20 and the outer surface of the pipe material 3 to connect the inside of the pipe material 3 to the ground E outside the self-drilling bit 5 via the inlet 16, and a gap S is also formed between the closing wall 22 formed in the connection part 20 and the pipe material 3.

And with the self-drilling bit 5, groundwater w from underground E can flow from the inlet 16 through the bit flow path 21, through the gap S, into the hollow passage 7 of the pipe material 3, and then discharged from the pipe material 2 at the end of insertion. This allows groundwater w to be discharged outward from the ground surface G from the self-drilling bit 5, which is the innermost part of the underground drainage device 1.

In the above embodiment and modified example, the case where the gap S is formed between the internal partition 13 inside the connecting pipe 4 and the closing wall 22 inside the self-drilling bit 5 has been described, but it is not limited to forming the gap S. In addition, a communication part in which the hollow passage 7 communicates with the flow path 15 or the bit part flow path 21 may be formed in the pipe material 2, 3 inserted into the connecting pipe 4 or the self-drilling bit 5 by notching or drilling. When a communication part is formed in the pipe material 2, 3, the thread groove 12 of the first connecting part 10 may be formed so that it reaches the internal partition 13 so that the pipe material 2 inserted into the first connecting part 10 abuts against the internal partition 13. This allows the internal partition 13 to function as a stopper that regulates the insertion amount of the pipe material 2 to be screwed into the first connecting part 10.

Figure 9 shows a modified version of the underground drainage device 1 of the above embodiment. Figure 9(A) is an explanatory diagram showing the underground drainage device 1 according to this modified version with the connecting pipe 4 in section, and Figure 9(B) is a cross-sectional view taken along line D-D in Figure 9(A).

The underground drainage device 1, including the pipes 2, 3 and connecting pipe 4, is made of polyvinyl chloride, which is easy to work with, and is inserted into a pre-boring hole excavated in the ground E.

As in the above embodiment, the first and second connection parts 10, 11 at both ends of the length of the hollow cylindrical connecting pipe 4 are inserted and connected to the hollow pipes 2, 3. In a modified example, the pipes 2, 3 and the connecting pipe 4 are connected by inserting the pipes 2, 3 into the connecting pipe 4 so that they fit into the connecting pipe 4. The ends 2a, 3a of the two pipes 2, 3 are butted together inside the connecting pipe 4, thereby connecting the hollow passages 7 to each other.

In addition, a plurality of notches 23 are formed at appropriate intervals in the circumferential direction of the end 3a of one pipe material 3 that is butted against the other pipe material 2. A water passage portion 24 is formed by dividing the end 3a into the notches 23 and the end 2a of the other pipe material 2.

In the illustrated example, multiple notches 23 are formed, but at least one notch may be formed. Although the notch 23 is shown to be formed in the pipe material 3 connected to the second connection part 11, this is not limiting, and the notch 23 may be formed in the pipe material 2 connected to the first connection part 10 instead of the pipe material 3 connected to the second connection part 11, or may be formed in both pipe materials 2, 3.

The configuration of the connecting pipe 4 is the same as that of the above embodiment, except that it does not have an internal partition 13. The first connecting part 10 has a flow path 15 formed between the inner surface of the first connecting part 10 and the outer surface of the pipe material 2 inserted into this first connecting part 10, for connecting the hollow passage 7 of the pipe material 2 to the ground E into which the underground drainage device 1 is inserted. The flow path 15 has an inlet 16 that opens toward the ground E outside the connecting pipe 4.

The flow path 15 is also connected to the water passage 24 on the side opposite the inlet 16. This allows the first connection 10 to be connected in series from the inlet 16 to the flow path 15, the water passage 24, and the hollow passage 7 of the pipe 2.

Even in the modified example, as in the above embodiment, the inner diameter of the first connection part 10 is partially increased at an appropriate circumferential position on the inner surface of the first connection part 10 from the longitudinal end of the connection pipe 4 along the longitudinal direction of the first connection part 10 to form a groove-like groove part 17, and this groove part 17 forms a flow path 15 between the inner surface of the first connection part 10 and the outer surface of the pipe material 2.

In addition, where the groove portion 17 is formed, a protruding ridge portion 18 is formed, which bulges out from the outer surface of the first connection portion 10 of the connection pipe 4.

In the illustrated example, four flow paths 15 are formed at equal intervals around the circumference of the first connection part 10, but it is sufficient if one or more flow paths 15 are provided.

Of course, even with such a modification, the same effects as the above embodiment can be achieved.

REFERENCE SIGNS LIST 1 underground drainage device 2, 3 pipe material 4 connecting pipe 5 self-drilling bit 6 underground drainage structure 8 thread 10 first connecting part 11 second connecting part 12 thread groove 13 internal partition 14 through hole 15 flow path 16 inlet 17 grooved part 20 connecting part 21 bit part flow path E underground G ground surface w groundwater

Claims (7)

An underground drainage device that is inserted into the ground and drains groundwater that has infiltrated into the ground,
The pipe includes a first pipe and a second pipe, each of which is hollow inside, and a hollow cylindrical connecting pipe that connects the first pipe and the second pipe,
The connecting pipe has a first connecting portion at one end side in the pipe axis direction into which one end of the first pipe material is inserted and connected, and a second connecting portion at the other end side in the pipe axis direction into which one end of the second pipe material is inserted and connected,
A flow path is formed between the first connection part and the first pipe material, the flow path having an inlet opening toward the ground outside the connecting pipe and toward the other end side of the first pipe material , for connecting the inside of the first pipe material to the ground,
The underground drainage device is configured so that the inlet of the flow path, the other end of the first pipe, one end of the second pipe, and the first connection portion of the connecting pipe are all oriented obliquely downward, and the first pipe is positioned below the second pipe, and the other end of the first pipe is positioned so as to be exposed from the ground to the ground surface as an insertion termination,
This underground drainage device is characterized in that water flowing into the flow path from the inlet flows diagonally upward within the flow path away from the insertion end, then flows into the inside of the first pipe material and flows diagonally downward inside the first pipe material toward the insertion end. The underground drainage device according to claim 1, characterized in that at least one of the flow paths is formed in the first connection part. The underground drainage device according to claim 1 or 2, characterized in that the first connection part has a groove-shaped part formed by partially increasing the inner diameter of the first connection part, and the flow path is formed between the groove-shaped part and the first pipe material. The underground drainage device according to any one of claims 1 to 3, characterized in that the connecting pipe has an internal partition that separates the first connecting portion from the second connecting portion, and the internal partition has a through hole that communicates with the inside of the first pipe material and the second pipe material connected to the connecting pipe. The underground drainage device according to any one of claims 1 to 4, characterized in that the first pipe material and the second pipe material have threads formed on their outer peripheries, the first and second connection parts of the connecting pipe have thread grooves formed on their inner peripheries, and the first pipe material and the second pipe material are screwed into the first and second connection parts, respectively. a self-drilling bit having a connection portion into which the other end of the second pipe is inserted and connected;
An underground drainage device as described in any one of claims 1 to 5, characterized in that the connection portion has a bit portion flow path formed between the connection portion and the second pipe material for connecting the inside of the second pipe material to the ground outside the drilling bit. An underground drainage structure characterized by using an underground drainage device according to any one of claims 1 to 6.

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