JP6353687B2 - Boring rod extension method and boring device - Google Patents

Description

  The present invention relates to a boring rod extension method and a boring device.

  In tunnel construction, in order to understand the geology and groundwater conditions in front of the face, survey boring may be carried out from the tunnel face or the widened part formed near the face toward the front of the face.

When conducting such survey boring, a boring hole having a predetermined extension (predetermined depth) is formed by adding an extending rod member (extending rod) to the boring rod (see, for example, Patent Document 1). ).
Therefore, when adding the extension rod, as shown in FIG. 3, it is necessary to open the end of the boring rod 101 or to cut off a part of the boring rod 101.

Japanese Patent Laid-Open No. 2005-9603

In the boring work, if the hole wall of the boring hole collapses, the excavation tool or the like may be restrained and the construction may become difficult.
In particular, in the case of horizontal boring (horizontal boring) such as survey boring and drain boring in tunnel construction, the pressure in the boring hole 102 is temporarily released when the boring rod 101 is added (extended). For this reason, the groundwater W suddenly flows into the borehole 102 and the risk of hole wall collapse increases.

  From such a point of view, an object of the present invention is to propose a boring rod addition method and a boring device capable of extending the boring rod while maintaining the pressure in the boring hole.

In order to solve the above-described problems, a boring rod addition method according to the present invention includes a preparation step of disposing an extension rod in a pressure vessel, a pressurization step of pressurizing the inside of the pressure vessel, and the pressure vessel. A step of adding the extension rod to the base end of the boring rod, and the boring rod is inserted into the boring hole with the base end disposed in the pressure vessel. cage, wherein in the pressing step is the pressure vessel was pressurized to the pressure vessel so that the same pressure and water pressure in the borehole with filled with water, in the replenishment process, pressurized the Separating the base end of the boring rod from a water swivel or a connecting rod connected to the water swivel in a pressure vessel; An operation of connecting the extension rod to the base end portion of the rod, an operation of reconnecting the water swivel or the connection rod to the base end portion of the boring rod via the extension rod, and the inside of the pressure vessel It is characterized by performing the work of draining water .

  According to such a boring rod adding method, since the rod member is added while maintaining the pressure in the boring hole, ground water can be prevented from flowing into the boring hole when the boring rod and the pump are disconnected. Therefore, the risk of collapse of the hole wall can be reduced.

Further, the boring device of the present invention includes a boring rod for drilling a boring hole, a pre-pender installed at a hole of the boring hole, a pump connected to the boring rod, and a gap between the pre-pender and the pump. A pressure vessel disposed in the pressure vessel, and an extension rod joined to the boring rod housed in the pressure vessel, the boring rod being inserted into the pre-pender, and a base end portion of the boring rod Is inserted into the pressure vessel, and the pressure vessel can accommodate an extension rod added to the boring rod.

  The boring device preferably includes a mount for supporting the boring rod and a jig for holding the extending rod inside the pressure vessel.

  According to such a boring device, the boring rod can be added in the pressure vessel. If the boring rod is added while the pressure in the pressure vessel is equal to the pressure in the borehole, groundwater can be prevented from flowing into the borehole rapidly.

  According to the boring rod adding method and boring apparatus of the present invention, it is possible to extend the boring rod while maintaining the pressure in the boring hole.

(A)-(d) is a longitudinal cross-sectional view which shows typically each process of the boring rod addition method of this embodiment. It is a cross-sectional view schematically showing the pressure vessel of the present embodiment. It is a longitudinal cross-sectional view which shows the conventional boring rod addition method typically.

In the present embodiment, a case will be described in which survey boring is performed toward the front of the face in tunnel construction.
As shown in FIG. 1A, a boring device 1 used for survey boring includes a boring rod 2, a pre-pender 3, a pump 4, and a pressure vessel 5.

  The boring rod 2 rotates about the central axis by the power of a boring machine (not shown), thereby cutting the ground G to form the boring hole 6.

The boring rod 2 is constituted by a hollow cylindrical member. A tip bit 21 is fixed to the tip of the boring rod 2.
The boring rod 2 is formed by connecting a plurality of rod members. When extending the boring rod 2, an extending rod member (extending rod 22) is added to the base end portion of the existing boring rod 2 (see FIG. 1D).

A pump 4 is connected to the base end of the boring rod 2 via a connecting rod 2a.
The boring rod 2 sends the high-pressure water sent from the pump 4 to the tip bit 21.

The boring rod 2 passes through the pre-pender 3 and is inserted into the boring hole 6.
Further, the base end portion of the boring rod 2 is inserted into the pressure vessel 5 and is connected to the connecting rod 2 a in the pressure vessel 5.

The pre-pender 3 is water stopping means installed at the hole of the boring hole 6.
The pre-pender 3 shields the gap between the boring hole 6 and the boring rod 2 at the hole of the boring hole 6.

  The pre-pender 3 according to the present embodiment includes a main body portion 31, an attachment portion 32, and a seal portion 33. Note that the configuration of the pre-pender 3 is not limited.

The main body 31 is made of a tubular member having an inner diameter larger than the outer diameter of the boring rod 2.
One end of the main body 31 is inserted into the boring hole 6, and the other end projects from the boring hole 6. Although the material which comprises the main-body part 31 is not limited, For example, what is necessary is just to use a steel pipe.

The main body portion 31 is formed with a drain port (not shown). A drain pipe 9 is connected to the drain port.
The drain pipe 9 is configured to be opened and closed by a valve 8.

  When drilling the boring hole 6, the drain pipe 9 is opened and closed by the valve 8 to control the amount of drainage from the boring hole 6, thereby preventing the wall of the boring hole 6 from collapsing and the inside of the boring hole 6 being necessary. This prevents higher pressure.

  The attachment portion 32 is in close contact with the outer surface of the main body portion 31 and the inner wall surface of the boring hole 6 and shields the gap between the main body portion 31 and the boring hole 6. In addition, although the material which comprises the attaching part 32 will not be limited if it has sufficient proof strength with respect to the groundwater pressure in the boring hole 6, the cement-type member is used in this embodiment.

The seal portion 33 is a ring-shaped member and is disposed inside the main body portion 31.
The seal portion 33 is in close contact with the outer surface of the boring rod 2 and supports the boring rod 2 in a rotatable manner. The material which comprises the seal | sticker part 33 will not be limited if it has sufficient proof strength with respect to the groundwater pressure in the boring hole 6. FIG.

The pump 4 is connected to the base end portion of the connecting rod 2 a through the water swivel 7, and feeds high-pressure water to the tip of the boring hole 6 through the connecting rod 2 a and the boring rod 2.
A valve 8 is interposed between the pump 4 and the water swivel 7.

The pressure vessel 5 is a sealable box-shaped member disposed between the pre-pender 3 and the pump 4 (water swivel 7).
The pressure vessel 5 has a shape that can accommodate the extension rod 22.

  In the present embodiment, the pressure vessel 5 is formed in a box shape, but the shape of the pressure vessel 5 is not limited. Moreover, the material which comprises the pressure vessel 5 will not be limited if it has the intensity | strength which can endure the water pressure in the boring hole 6 (ground water pressure of the ground G).

  As shown in FIG. 1A and FIG. 2, a base 51 for supporting the boring rod 2 and a jig 52 for holding the extension rod 22 are disposed inside the pressure vessel 5. ing. The jig 52 is configured to be able to hold the extension rod 22 above the gantry 51.

An insertion hole for inserting the boring rod 2 is formed in the wall surface of the pressure vessel 5 on the face side, and an insertion hole for inserting the connecting rod 2a is formed in the wall surface of the pressure vessel 5 on the pump side. Is formed.
The base end portion of the boring rod 2 is connected to the water swivel 7 via a connecting rod 2a.

  The insertion hole of the pressure vessel 5 is provided with a sealing material (not shown) for sealing the gap with the boring rod 2 or the connecting rod 2a so that the pressure vessel 5 can be sealed. . In addition, the material which comprises a sealing material will not be limited if the sealing of the pressure vessel 5 is possible and the rotation of the boring rod 2 is not prevented.

The boring hole 6 is drilled by injecting high-pressure water sent from the pump 4 from the tip bit 21 and rotating the boring rod 2.
The boring hole 6 is drilled to a predetermined depth while extending the boring rod 2.

The boring rod 2 is extended by adding an extending rod 22 to the base end of the boring rod 2.
The boring rod adding method includes a preparation step, a pressurizing step, and an adding step.

The preparation step is a step of disposing the extension rod 22 in the pressure vessel 5 as shown in FIG.
The extension rod 22 is installed on the jig 52.

The preparation step may be performed in parallel with the boring of the boring hole 6 or may be performed by interrupting the boring of the boring hole 6.
When the drilling of the boring hole 6 is interrupted, the valve 8 disposed between the pump 4 and the water swivel 7 is shielded as the pump 4 is stopped. By shielding the valve 8, the flow of water from the distal end side to the proximal end side of the boring rod 2 is stopped, and inflow of groundwater (earth and sand) into the boring rod 2 is prevented.

The pressurizing process is a process of pressurizing the inside of the pressure vessel 5.
First, water W is poured into the pressure vessel 5 as shown in FIG.

Next, the pressure vessel 5 is sealed, and the water W in the pressure vessel 5 is pressurized by a pump.
The pressurization in the pressure vessel 5 is performed until it becomes approximately the same as the water pressure in the borehole 6 (in the ground G).

  For pressurization in the pressure vessel 5, a pump 4 for feeding high-pressure water used for drilling the boring hole 6 may be used, or a separately provided pump may be used.

  The adding step is a step of adding the extension rod 22 to the proximal end portion of the boring rod 2 in the pressurized pressure vessel 5. When performing the adding process, the drilling of the boring hole 6 is interrupted.

  In the adding step, first, as shown in FIG. 1C, the boring rod 2 and the connecting rod 2a are divided (separated) in the pressure vessel 5.

Next, as shown in FIG. 1D, an extension rod 22 is disposed between the boring rod 2 and the connecting rod 2a, and the boring rod 2, the connecting rod 2a, and the extending rod 22 are connected. To do.
The connecting rod 2a is disposed between the boring rod 2 and the connecting rod 2a by being removed from the jig 52 and dropped onto the mount 51.

  In addition, the connection location of the extension rod 22 is not limited. For example, a part of the boring rod 2 may be divided in the pressure vessel 5 and the extension rod 22 may be connected therebetween. Further, when the boring rod 2 and the water swivel 7 are directly connected and the connecting portion is disposed in the pressure vessel 5, the boring rod 2 is separated from the water swivel 7, and the boring rod 2 An extension rod 22 may be interposed between the water swivel 7 and the water swivel 7.

When the extension rod 22 is connected, the water W in the pressure vessel 5 is drained to release the pressure in the pressure vessel 5 to atmospheric pressure.
When the pressure in the pressure vessel 5 is released, drilling of the boring hole 6 is resumed.

  As described above, according to the boring device and the boring rod adding method of the present embodiment, the extension rod 22 is added in the sealed pressure vessel 5, and therefore the pressure in the boring hole 6 can be maintained.

  That is, when the boring rod 2 is disconnected from the pump 4 (when the boring rod 2 is divided), groundwater is prevented from flowing into the boring hole 6 and the hole wall of the boring hole 6 collapses. Can be prevented.

Moreover, the spring water in the base end part of the boring rod 2 can be prevented, and work can be performed easily.
Moreover, it is possible to prevent the tip bit 21 and the like from being clogged by the earth and sand flowing into the boring rod 2 (tip bit 21).

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.
For example, although the case where the inside of a pressure vessel was pressurized using water was demonstrated in the said embodiment, the pressurization method in a pressure vessel is not limited. For example, you may pressurize gas in a pressure vessel.

The jig for holding the extension rod may be provided with an arm for moving the extension rod to a predetermined position when the extension rod is connected to the boring rod.
Further, a member for guiding the extension rod from the jig to the gantry may be installed in the pressure vessel.

DESCRIPTION OF SYMBOLS 1 Boring apparatus 2 Boring rod 21 Tip bit 22 Extension rod 3 Pre-pender 4 Pump 5 Pressure vessel 51 Base 52 Jig 6 Boring hole 7 Water swivel 8 Valve 9 Drain pipe G Ground W Water

Claims (3)

A preparation step of disposing an extension rod in the pressure vessel;
A pressurizing step of pressurizing the inside of the pressure vessel;
A step of adding a boring rod in the pressure vessel, the step of adding the extension rod to the base end of the boring rod;
The boring rod is inserted into the boring hole in a state where the base end portion is disposed in the pressure vessel,
Wherein in the pressurization step, the pressure vessel along with filled with water, under pressure to the pressure vessel so that the same pressure and water pressure of the boring hole,
In the adding step, in the pressurized pressure vessel, an operation of separating a base end portion of the boring rod from a water swivel or a connecting rod connected to the water swivel;
Connecting the extension rod to the base end of the boring rod;
Reconnecting the water swivel or the connecting rod to the base end of the boring rod via the extension rod;
A method for adding a boring rod, comprising: draining water in the pressure vessel . A boring rod for drilling boring holes;
A pre-pender installed in the hole of the boring hole;
A pump coupled to the boring rod;
A pressure vessel disposed between the pre-pender and the pump;
A boring device comprising: an extension rod added to the boring rod housed in the pressure vessel ;
The boring rod is inserted through the pre-pender,
Proximal end of the boring rod, boring apparatus characterized by being inserted into the pressure vessel.   The boring apparatus according to claim 2, further comprising a mount for supporting the boring rod and a jig for holding the extending rod inside the pressure vessel.

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