JPH10159078A - Drain pipe and dewatering method of soft ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a water collection capacity in underground by providing a plurality of conical projections communicating with the inside of a drain pipe body on the outer wall of the peripheral wall of the drain pipe body. SOLUTION: A plurality of water flowing holes 1b are penetrated on the peripheral wall 1a to constitute a pipe body with a hole 1. In order to enlarge a water collection area, a plurality of conical projections 2 are protruded on the outer wall of the peripheral face 1a, and a through hole 2a communicating with the inside of the pipe body with the hole 1 is penetrated in the projections 2. Next, when a drain pipe with a projection D is placed in the soft ground, underground water is collected from the water passing hole 1b to the inside of the pipe, and the underground water is collected from the water passing hole 2a penetrated in the projection 2. Furthermore, since the projection 2 is buried in the ground at the time of placing of the drain pipe D, the ground is compacted only by a buried part, and floating of the drain pipe D can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing excess pore water (hereinafter referred to as groundwater) from a soft ground containing a large amount of water that causes a liquefaction phenomenon. It relates to the drain pipe used.

[0002]

2. Description of the Related Art Conventionally, a method of pumping groundwater using a perforated drain pipe has been widely used in order to prevent liquefaction on soft ground. That is, conventionally, FIG.
As shown in the figure, after the perforated drain pipe 10 having a large number of water holes 10b formed in the peripheral wall 10a is poured into the ground, groundwater is discharged from the water holes 10b of the perforated drain pipe 10. The construction method was generally performed.

[0003]

However, it is necessary to provide a shaft with an auger or the like as a pre-stage for driving a perforated drain pipe into the ground. In this case, the shaft wall of the shaft becomes loose, and The perforated drain pipe could not be brought into close contact with the pit wall. In other words, a gap is created between the perforated drain pipe and the shaft wall of the shaft, resulting in loosening of the ground, subsidence of the ground, and inability to efficiently collect groundwater contained in the ground. It was.

[0004] Further, since the perforated drain pipe cannot be firmly driven when the shaft wall of the shaft is loose, there arises a problem that the perforated drain pipe is inconveniently lifted or wobble at the time of construction. Was.

[0005] The present invention has been made to solve the above-mentioned problems, and a drain pipe capable of obtaining a high water collection rate by increasing the degree of close contact with a shaft, and a method of draining soft ground using the drain pipe. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention provides a perforated pipe body having a plurality of projections formed on the outer wall of the perimeter wall of a perforated pipe body having a plurality of water holes formed in the perimeter wall. Using. Further, the projection may be fixed in advance by welding or the like to the outer wall of the peripheral wall of the perforated pipe body,
In the invention according to claim 2, there is provided a means for forming an insertion hole in the peripheral wall of the perforated pipe main body, and for accommodating and holding a projection in the inside of the perforated pipe main body so as to project toward the insertion hole. Used selectively. Further, in the invention according to claim 3, means is provided in which the projection is provided with a through hole communicating with the inside of the perforated pipe main body.

According to the present invention, a shaft is drilled in the soft ground using a casing auger and a projection is formed inside the pipe of the perforated pipe body as a method of draining the soft ground to prevent the liquefaction phenomenon. After inserting the drain pipe housed and held so as to protrude toward the casing auger, the casing auger is removed from the shaft, and the protrusion is projected outside the drain pipe to be embedded in the pit wall of the shaft. In this way, the drain pipe is cast into the shaft, and groundwater collected inside the drain pipe is discharged to the ground surface side. That is, in this method, a drain pipe having a structure capable of projecting projections was used.

[0008] As another draining method, the present invention provides:
While drilling a shaft in soft ground using a casing auger, after inserting a drain pipe with a projection fixed to the outer wall of the peripheral wall of the perforated pipe body into the casing auger, remove the casing auger from the shaft, At the same time as compacting the shaft wall of the shaft, the drain pipe and the shaft are brought into close contact with each other to drive the drain pipe into the shaft, and the groundwater collected inside the drain pipe is discharged to the ground surface side. Was used. That is, in this construction method, an integrated drain pipe was used in which projections were previously fixed to the peripheral wall of the perforated pipe main body.

[0009]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of a drain pipe D according to the present invention.
Is a perforated pipe main body formed by penetrating a plurality of water holes 1b in the peripheral wall 1a, and a plurality of conical projections 2 are protruded from the outer wall of the peripheral wall 1a. In the present embodiment, the projection 2 is provided with a through hole 2 a communicating with the inside of the perforated pipe main body 1.

In the drain pipe D having a projection as described above, the ground water is collected into the pipe from the water passage hole 1b by being poured into the soft ground. Underground water can also be collected from the hole 2a. Accordingly, since the water collecting area is larger by the surface area of the projection 2 than the conventional perforated drain pipe D, it is possible to collect groundwater over a wider range. Further, since the projection 2 is buried in the ground when the drain pipe D is cast, the ground can be compacted by the buried portion, and at the same time, the drain pipe D can be more firmly fixed to the ground. Floating of the drain pipe D can be prevented. The through hole 2a for the projection 2 in the present embodiment can be omitted depending on the material and shape of the projection 2. Even in this case, among the effects described above, the compaction of the ground and the drain pipe Similar effects can be obtained for fixing D.

Next, FIG. 2 shows a second embodiment of the drain pipe D. In the drain pipe D of the above embodiment, the projection 2 is welded to the outer wall of the peripheral wall 1a of the perforated pipe main body 1 or the like. While the drain pipe D according to the present embodiment is of a fixed integral type, the projection 2 can be appropriately protruded from the inside of the perforated pipe main body 1. That is, the drain pipe D of the present embodiment has an insertion hole 1c in which the projection 2 can protrude from the peripheral wall 1a of the perforated pipe body 1 having the water passage hole 1b.
And a conical projection 2 having a through hole 2a formed therein is housed and held inside the perforated pipe body 1 while facing the insertion hole 1c. Specifically, as shown in FIG. 3, a horizontal rod 2b and a vertical rod 2c that constitute a skeleton for reinforcement are provided in the hollow interior of the protrusion 2, and the horizontal rod 2
The projection 2 is housed and held in the perforated pipe main body 1 by fixing b to the fixture 3. In the figure,
Reference numeral 2d denotes a flange, which is engaged with the insertion hole 1c and has a protrusion 2d.
This is for preventing falling off.

In FIG. 3, reference numeral 4 denotes a jig comprising a conical body 4a and a cylindrical body 4b, which is hung in the perforated pipe body 1 by a wire 5 attached to the conical body 4a. Here, before the jig 4 sets the projection 2 together with the fixture 3 in the perforated pipe main body 1,
Is suspended below the lower end of the.

The projecting operation of the projection 2 in the drain pipe D having the above construction will be described with reference to FIGS. 4 and 5. First, the jig 4 is pulled up by winding up a wire 5 or the like, whereby The body 4a is deformed so that the fixture 3 is pushed open (see FIG. 4). Here, in the present embodiment, the notch 3a is provided on one surface of the fixture 3, so that the deformation of the fixture 3 by the jig 4 is performed smoothly.

By further lifting the jig 4 from the above-described state, the horizontal rod 2b provided on the projection 2 comes into contact with the conical body 4a of the jig 4, and starts pushing the projection 2 in the horizontal direction. When the horizontal rod 2b comes into contact with the cylindrical body 4b of the jig 4 by pulling up the protrusion 4, the protrusion 2 can be completely protruded outside the pipe main body 1 through the insertion hole 1c ( (See FIG. 5).

In the above embodiment, the projection 2 has a hollow structure. However, it is a matter of course that a solid body having a solid structure can be used. in this case,
It is also possible to omit the through hole 2a from the projection 2. or,
The shape of the projection 2 is not limited to the conical shape described above, but may be a cylindrical shape,
Other shapes such as a spherical shape and a cubic shape may be used. Further, the holding structure of the projection 2 is not limited to the structure in which the projection 2 is held by the mounting member 3 by the lateral rod 2b as in the above-described embodiment, and has a structure in which the projection 2 is directly fixed to the mounting member 3 as shown in FIG. There may be. Even in this case, the projection 2 can be appropriately protruded in accordance with the deformation operation (push-open operation) of the attachment 3 by the jig 4.

Subsequently, the drain pipe D of the above embodiment is used.
The method of draining soft ground using the method described with reference to FIGS. First, FIG. 7 shows the excavation process of a shaft.
The soft ground G is excavated using an excavator such as a casing auger K, and a shaft is provided (see FIG. 7A). Next, the drain pipe D in which the projection 2 and the jig 4 are accommodated in the perforated pipe main body 1 is set in the casing auger K (see FIG. 7B). Here, the jig 4 is suspended by the wire 5 in the perforated pipe main body 1 so as to be located below the lower end of the fitting 3 of the projection 2.

Next, FIG. 8 shows a driving process of the drain pipe D. In FIG.
Is removed from the soft ground G in a state where is opened. At the same time as the casing auger K is raised, the jig 4 is pulled upward by winding the wire 5 or the like. In this process, the projection 2 is made to project from the insertion hole 1c of the perforated pipe main body 1 by the projection operation of the projection 2 described with reference to FIGS. Can be buried in the wall. Further, by completely removing the jig 4 together with the casing auger K from the shaft, all the projections 2... 2 housed and held in the perforated pipe main body 1 are projected, and the operation of setting the drain pipe D is completed. Then, the underground water collected inside the drain pipe D is discharged to the ground surface side.

According to the drain pipe D cast on soft ground by the above-described method, the peripheral wall 1 of the perforated pipe body 1
Since the water is collected from the through hole 2a provided in the projection 2 together with the water collection through the water hole 1b provided in the hole a, the water collection is performed in comparison with the conventional drain pipe having the water hole provided only in the peripheral wall. The area is large and water can be collected over a wide area. Further, when a shaft is excavated using the casing auger K in order to cast the drain pipe D, the shaft wall H of the shaft T is loosened as shown in FIG.
Is protruded and buried in the pit wall H, soil and soil corresponding to the volume of the projection 2 are compacted, so that the degree of adhesion between the drain pipe D and the pit wall H can be increased, and The underground water can be exuded from the underground by the advance to the wall H, and the underground water collecting efficiency can be improved. Further, since the projection 2 is pierced into the pit wall H, the drain pipe D can be firmly fixed to the soft ground.

In the above-described method, the drain pipe D from which the projection 2 can project is used. However, the object of the present invention can be achieved by using a drain pipe D integrated with the projection shown in FIG. Can be. In this case, it is necessary to use a casing auger K capable of inserting the drain pipe D in a state where the projection 2 protrudes, but by removing the casing auger K from the shaft, the shaft T of the slackened shaft T is removed. The pit wall H is compacted naturally or by giving vibration to the drain pipe D, and at the same time, the drain pipe D and the vertical shaft can be brought into close contact with each other. The same effect as the above-mentioned method can be obtained.

[0020]

As described above, according to the present invention,
Compared with the conventional drain pipe, the water collecting area is larger by the surface area of the projection, so that groundwater can be collected over a wider area. In addition, loosening of the shaft wall of a shaft excavated with an auger etc. is compacted by the protrusion piercing the shaft wall, and the earth and sand corresponding to the volume of the protrusion is projected on the pipe side, so that the shaft wall and the drain pipe Can improve the degree of adhesion of underground water and improve the efficiency of collecting groundwater. Furthermore, since the drain pipe is firmly fixed to the ground by the projection, it is possible to prevent the drain pipe from rising during construction or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a drain pipe according to the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the drain pipe according to the present invention.

FIG. 3 is an enlarged sectional view of the same.

FIG. 4 is an operation explanatory view of the same.

FIG. 5 is an operation explanatory diagram of the same.

FIG. 6 is a longitudinal sectional view showing another embodiment of the drain pipe having a protruding projection.

FIG. 7 is a process diagram of the drainage method according to the present invention.

FIG. 8 is a process diagram of the same.

FIG. 9 is an enlarged cross-sectional view showing the relationship between the drain pipe and the pit wall after casting.

FIG. 10 is a perspective view showing a conventional drain pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Perforated pipe main body 1a Perimeter wall 1b Water passage hole 1c Insertion hole 2 Projection 2a Through hole 3 Mounting tool 4 Jig 5 Wire D Drain pipe K Casing auger T Vertical shaft H Horizontal wall

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[Procedure amendment]

[Submission date] December 13, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (5)

[Claims] 1. A drain pipe, wherein a plurality of projections are provided on the outer wall of the peripheral wall of a perforated pipe body having a plurality of water holes formed in the peripheral wall. 2. The drain pipe according to claim 1, wherein an insertion hole is formed in the peripheral wall of the perforated pipe body, and a projection is housed and held inside the perforated pipe body so as to protrude toward the insertion hole. . 3. The drain pipe according to claim 1, wherein the projection has a through hole communicating with the inside of the perforated pipe body. 4. A shaft is drilled in soft ground using a casing auger, and a drain pipe having a perforated pipe main body and a projection housed therein is inserted into the casing auger. Removed from the shaft, the protrusion is projected outside of the pipe of the drain pipe to compact the pit wall of the shaft, and at the same time the drain pipe and the shaft are brought into close contact with each other, thereby driving the drain pipe into the shaft, A method for draining soft ground, comprising discharging groundwater collected inside the drain pipe to the ground surface side. 5. A vertical shaft is bored in soft ground using a casing auger, and a drain pipe having a projection fixed to an outer wall of a peripheral wall of a perforated pipe body is inserted into the casing auger. Removing the drain pipe from the shaft, placing the drain pipe in the shaft, and discharging groundwater collected inside the drain pipe to the ground surface side, a method of draining soft ground. .