JPH0813462A - Drainage boring - Google Patents

Abstract

PURPOSE:To drill a hole and install a drainage pipe in the hole in less numbers of process without flowing out of sand by treating only water and prevent sand after the installation by using the drainage pipe as a screen pipe and take in only water and perfectly prevent sand from flowing out during the work and also after the work. CONSTITUTION:A guide pipe 2 in which a cut-off box 4 is attached to the opening of hole is installed. A lost bit 6 with a check valve 5 is provided at the front end thereof. A casing 7 in which the nearby place of the front end is formed as a screen pipe 9 and the upper part is formed as a pipe 15 without holes, is inserted in the guide pipe 2. An inner rod 34 is connected to the lost bit 6 and water passing the inner rod 34 is poured from the lost bit 6 at the front end on excavating to drain water and discharge mud from the clearance around the casing 7. After completion of boring only the inner rod 34 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drainage boring method for treating spring water from groundwater.

[0002]

2. Description of the Related Art As a method of lowering the groundwater level in the ground by treating spring water from groundwater associated with tunnel construction and root cutting work, a hole is drilled with a hole drilling machine and a drainage pipe is placed in the hole. There is known a method of installing water and inducing water with this drainage pipe.

However, in the unconsolidated stagnant water sand layer and gravel layer, sand may flow due to high spring water pressure, which may cause the ground to collapse. In order to prevent such outflow of sand and the like, a screen tube having a slit is installed as a drainage pipe to block sand and take in only water.

FIG. 7 to FIG. 9 show one example thereof, and although not shown in the drawings, a spout preventing device at the mouth is formed by attaching a water shut-off box to a guide pipe to which a flange and a drain valve are attached.
30 is installed, and a casing 7 having a lost bit 6 provided with a check valve 5 at its tip so as to penetrate therethrough is inserted and drilled with this.

At the time of this drilling, drilling water is sent from the pump into the casing via a swivel attached to the upper end of the casing 7, is poured from the tip lost bit 6 and passes outside the casing 7. Drainage and sludge reach the mouth spring prevention device 30 from the clearance around the casing 7, and are discharged from the drain valve attached here.

After excavating to a predetermined depth, a drainage pipe with a screen pipe 9 having a non-perforated pipe 15 at the upper portion is inserted and set, the lost bit 6 with the check valve 5 is dropped, and the casing 7 is pulled out by a pipe extractor. .

In this way, a drainage pipe is installed by the screen pipe 9 having the non-perforated pipe 15 at the upper part, and only water is taken in while preventing outflow of sand.

FIGS. 10 to 12 show another example, which is a double tube type lottery including an outer casing rod 31 having an outer bit 31a at the tip and a inner casing rod 32 having an inner bit 32a at the tip. This is the case when using percussion.

The outer casing rod 31 and the inner casing rod 32 are provided with a reverse water prevention device 33 near the tips, and after the completion of excavation, the inner casing rod 32 is removed and the upper portion of the non-perforated pipe 15 is drained by the screen pipe 9. Install the pipe.

Then, the outer casing rod 31 is pulled out and removed.

[0011]

However, in both the case of the single pipe drilling shown in FIGS. 7 to 9 and the case of the double pipe drilling shown in FIGS. Screen tube 9
The drainage pipe is installed after drilling,
In addition to the large number of steps and time-consuming work, it was not possible to completely stop the outflow of sand etc. when replacing the screen tube.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, and to perform drilling and installation of a drainage pipe in this hole by treating only water without sand outflow, with a small number of steps. In addition, by using a screen pipe for the drainage pipe, it can block sand after installation and take in only water, and can completely block outflow of sand during and after construction. To provide a construction method.

[0013]

In order to achieve the above-mentioned object, the present invention has a guide pipe having a water-stop box attached to the hole mouth, and has a lost bit with a check valve at the tip, near the tip. Insert the casing with the screen pipe as the screen pipe and the non-perforated pipe into this guide pipe for drilling, connect the inner rod to the lost bit, and at the time of drilling, pass the water passing through the inner rod from the tip lost bit. The gist is to remove the inner rod only after pouring out, draining and draining mud from the clearance around the casing, and after finishing drilling.

[0014]

According to the present invention, for drilling, a guide pipe having a water-stop box attached to the hole is installed, a lost bit with a check valve is provided at the tip, and a screen tube is provided near the tip.
This is done by inserting a casing with a non-perforated pipe into this guide pipe, and at the same time as drilling, water that passes through the inner rod is poured from the tip lost bit to drain and drain mud from the clearance around the casing. After completion of drilling, the casing can be used as it is as a drainage pipe by removing only the inner rod.

The drainage pipe has a screen tube. After the installation, the screen tube can block sand and take in only water.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 8 are vertical sectional front views of respective steps showing one embodiment of the drainage boring method of the present invention. First, a casing 1 having a ring bit 1a at its tip is excavated, and FIG.
The cement milk 3 is filled in the drill hole as shown in FIG.

Then, as shown in FIG. 3, a guide tube 2 in which a flange 2a and a drain valve 2b are attached to a tube body having substantially the same diameter as the casing 1a is inserted into the hole. By doing so, the cement milk 3 leaks through the guide tube 2, through the outside of the tube to the mouth of the hole, so if it leaks, push it in with a machine to ensure close contact between the ground and the guide tube 2, and Caulk your mouth. The cement used should be a fast-strength cement to save curing time.

The guide tube 2 is first inserted into the excavation hole,
After the insertion, the casing and the guide tube 2 may be connected by a boring machine to fill the cement milk 3.

When the cement around the guide tube 2 develops sufficient strength, as shown in FIG. 4, a water blocking box 4 for sealing the through portion with an elastic plate such as a rubber plate is attached, and the guide tube 2 is attached. The water stop box 4 constitutes the mouth spring prevention device 30.

Lost bit 6 equipped with check valve 5
Has a tip, and the tip portion is the screen tube 9,
The casing 7 having the non-perforated pipe 15 thereon is inserted, and the casing 7 is attached to the hole drilling machine to excavate.

The casing 7 has an inner rod 34 as a water supply pipe provided therein, and the inner rod 34 is connected to the lost bit 6 equipped with the check valve 5. Then, at the time of drilling, water passing through the inner rod 34 is poured out from the tip lost bit 6 to drain and drain mud from the clearance around the casing 7.

As a drilling method, an inner rod is used.
A method of giving a hit and a rotation only to 34 and giving a rotation only to the casing 7, a method of giving a hit and a rotation to both rods of inner rod 34 and casing 7, a method of giving a hit and a rotation to casing 7, A method of giving only rotation can be considered.

When the drilling is completed to the predetermined depth, as shown in FIG.
As shown in, the inner rod 34 is separated from the lost bit 6 provided with the check valve 5, and the inner rod 34 is removed.

As shown in FIG. 6, a drainage pipe 16 is attached to the non-perforated pipe 15 of the casing 7 to drain water, and the drainage valve 2b attached to the guide pipe 2 is closed.

Further, an openable / closable prebender 22 is installed at the connecting portion between the non-perforated pipe 15 and the drainage pipe 16, and this prebender 22 is provided with a pressure converter 19 in which a pressure gauge 17 and a measuring device 18 are connected, Further, the middle of the drain pipe 16 was branched, and the end of this branch pipe was connected to a notch tank 20 serving as a flow rate measuring means by a triangular weir.
Reference numeral 21 in the figure denotes a valve provided in the drainage pipe 16.

In this way, after the screen tube 9 having the non-perforated tube 15 at the upper end is installed as a drainage pipe,
The pressure is measured by the pressure gauge 17 and the flow rate is measured by the notch tank 20 to continuously observe the spring water.

[0027]

As described above, according to the water removing boring method of the present invention, only a small number of steps are required for drilling and installing a water draining pipe in the hole by treating only water without the outflow of sand. The drainage pipe can be used as a screen pipe to block sand after installation and to take in only water, and to completely prevent the outflow of sand during and after construction. Is.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a first step showing one embodiment of a water removing boring method of the present invention.

FIG. 2 is a vertical sectional front view of a second step showing one embodiment of the water removing boring method of the present invention.

FIG. 3 is a vertical sectional front view of a third step showing one embodiment of the water removing boring method of the present invention.

FIG. 4 is a vertical sectional front view of a fourth step showing one embodiment of the water removing boring method of the present invention.

FIG. 5 is a vertical sectional front view of a fifth step showing one embodiment of the water removing boring method of the present invention.

FIG. 6 is a vertical sectional front view of a sixth step showing one embodiment of the water removing boring method of the present invention.

FIG. 7 is a vertical sectional front view of a first step showing a conventional example.

FIG. 8 is a vertical sectional front view of a second step showing a conventional example.

FIG. 9 is a vertical cross-sectional front view of a third step showing a conventional example.

FIG. 10 is a vertical sectional front view of a first step of another conventional example.

FIG. 11 is a vertical sectional front view of a second step of another conventional example.

FIG. 12 is a vertical sectional front view of a third step of another conventional example.

[Explanation of symbols]

1 ... Casing 1a ... Ring bit 2 ... Guide pipe 2a ... Flange 2b ... Drainage valve 3 ... Cement milk 4 ... Water stop box 5 ... Backflow prevention valve 6 ... Lost bit 7 ... Casing 9 ... Screen pipe 15 ... Non-perforated pipe 16 ... Drain pipe 17 ... Pressure gauge 18 ... Measuring device 19 ... Pressure converter 20 ... Notch tank 21 ... Valve 22 ... Pre-bender 30 ... Spout prevention device 31 ... Outer casing rod 31a ... Outer bit 32 ... Inner casing rod 32a ... Inner Bit 33 ... Reverse water prevention device 34 ... Inner rod

Front page continuation (72) Inventor Yasuhiro Okada 8-14-14 Ginza, Chuo-ku, Tokyo Within Nissho Construction Co., Ltd. (72) Inventor Akira Higuchi 2-3-5 Shinozaki-cho, Edogawa-ku, Tokyo Higuchi Gikko Co., Ltd. Within

Claims (1)

[Claims] 1. A casing in which a guide pipe having a water-stop box attached to the hole mouth is installed, a lost bit with a check valve is provided at the tip, a screen pipe is provided near the tip, and a non-perforated pipe is provided at the top. Insert into this guide pipe and drill, connect the inner rod to the lost bit, and at the time of drilling, water passing through the inner rod is poured out from the tip lost bit and drainage and sludge are discharged from the clearance around the casing. A water drainage boring method characterized in that only the inner rod is removed after the completion of drilling.