JP4548838B2 - Drilling method - Google Patents

Description

 The present invention relates to a drilling technique using so-called “bored boring” that uses a machine capable of boring with a flexible rod.

Bending boring using a flexible boring machine has a wide range of applications because it can drill holes along any line.
For example, it is possible to prevent liquefaction in a region immediately below the existing building by drilling from a location separated from the existing building to a region directly below the existing building (see Patent Document 1).
In addition, it is possible to install a device at an arbitrary point, drill a hole in the ground along a predetermined line, and inject a filler into a desired region (see Patent Document 2).
Alternatively, the ground can be drilled along a predetermined line from a remote location to the contaminated soil, and the contaminated soil can be purified using the drilled borehole (Patent Document 3).
The applicant has already proposed these application examples.

 Here, when implementing various application technologies as described above, it is necessary to pull out a universal boring rod from one end of a boring hole drilled by bending boring and insert a necessary member into the drilled boring hole. .

However, in the case of soft ground such as sand ground, there is a possibility that the drilled boring hole may collapse or collapse by pulling out the free boring rod.
And even if the ground is relatively strong and the drilled boring hole does not collapse or collapse, after the free boring rod is pulled out, earth and sand, mud, etc. flow into the drilled boring hole. There is a risk of hindering the insertion of equipment necessary for the subsequent work.
Although the above-described techniques (Patent Documents 1 to 3) are useful techniques, they do not contribute to the problem.
JP 2004-60243 A Japanese Patent Laid-Open No. 2003-3459 JP 2004-5999 A

 The present invention has been proposed in view of the above-described problems of the prior art, and after drilling using a boring machine equipped with a flexible rod, the drilled borehole is collapsed or collapsed. Drilling method that can prevent and prevent foreign materials (such as earth and sand, muddy water, etc.) from flowing into the drilled borehole and hindering the insertion of equipment required for work The purpose is to provide.

 The drilling method of the present invention is a flexible hollow rod provided with drilling means (for example, a drilling fluid discharge hole 15) and a drilling direction control means (for example, a reaction plate 2 for correction) at the tip. In a drilling method (so-called “curved boring”) in which a boring hole is drilled using the (flexible rod 1), the hollow portions (12, 13) inside the rod (1) are drilled fluid (for example, bentonite). , Water) and the closing member (tip core portion 3) closing the rod tip (11) is configured to be detachable, and a drilling fluid is supplied from the drilling means (15). A drilling step in which the ground is drilled by spraying, and the closure member (3) is removed from the hollow rod tip (11) (for example, using the recovery device 4) and the hollow portion inside the rod (1) (13) Closure part to be recovered (to the tuyere 50 side) Equipment required for the recovery process and post-drilling work (for example, injection by the sleeve tube 5, confirmation of the ground condition by the TV camera 7, magnetic exploration by inserting the magnetic exploration device 9, sampling by the sampling device 10) (sleeve tube 5, An insertion step of inserting the TV camera 7, the magnetic exploration device 9, and the sampling device 10) into the hollow portion (13) inside the rod and moving to the tip of the hollow rod (11). 1).

 In the present invention, in the insertion step, when a device (5, 6, 7, 9, 10) necessary for work after drilling is inserted, the drilling fluid is inserted into the hollow space (13) inside the rod (1). Is preferably injected (Claim 2).

 In the present invention, in the closing member collecting step, the closing member (3) is removed from the hollow rod tip (11) and collected through the hollow portion (13) inside the rod (to the tuyere 50 side). At this time, it is preferable to inject the drilling fluid into a region closer to the rod tip (11) than the closing member (3) in the hollow space (12) inside the rod (claim 3).

According to the present invention having the above-described configuration, the hollow member (13) in the flexible rod (1) used in the bent boring is obtained by collecting the closing member (3) toward the tuyere (50). The necessary equipment as described above (for example, the sleeve tube 5, the TV camera 7, the magnetic exploration device 9, and the sampling device 10) can be positioned at the rod tip (11).
At that time, the flexible rod (1) has an effect of securing the moving path of the necessary equipment (5, 6, 7, 9, 10) described above, so even if the soft ground collapses, Devices (5, 6, 7, 9, 10) necessary for various operations can be arranged at predetermined positions via the hollow portion (13) inside the flexible rod (1). And since it is hard for a foreign material to penetrate | invade into the hollow part (12, 13) inside a flexible rod, installation of the apparatus by a foreign material is not disturbed.

Even if it is assumed that foreign matter has entered the hollow portions (12, 13) inside the flexible rod, the devices (5, 6, 7, 9, 10) necessary for the work after drilling are inserted in the present invention. In this case, if the drilling fluid is jetted into the hollow space (12, 13) inside the rod (Claim 2), the foreign matter existing in the hollow space (12, 13) inside the rod It is removed from the inside of the rod by the drilling fluid injected into the hollow spaces (12, 13).
Therefore, it is possible to prevent the possibility that the foreign matter as described above hinders the insertion of the devices (5, 6, 7, 9, 10) necessary for the work after drilling.

 Further, in the present invention, in the closing member collecting step, the closing member (3) is removed from the hollow rod tip (11) and collected through the hollow portion (13) inside the rod (to the tuyere 50 side). In doing so, since the drilling fluid is jetted to the rod tip (11) side region of the hollow space (12) inside the rod with respect to the closing member (3) (Claim 3), the closing member (3) ) In the region closer to the rod tip (11) than the rod tip, and foreign matter can be prevented from entering the hollow space (12, 13) of the rod from the rod tip (11).

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings (FIGS. 1 to 34).
1 to 34, the same members are denoted by the same reference numerals.

The present invention is, for example,
(A) After excavating a predetermined area by bending boring, inserting an injection sleeve equipped with a packer and injecting a solidified material or other chemicals;
(B) Inserting a TV camera at the tip of a curved boring to check the ground condition,
(C) Inserting a magnetic exploration device at the tip of a bent boring to conduct magnetic exploration;
(D) Inserting and collecting a sampling device at the tip of a bent boring (ground sampling),
Etc. are applicable.

  Here, the insertion of the injection sleeve of the item (a) described above is performed in order to enable efficient chemical injection, for example, in the chemical injection method.

  The insertion of the TV camera of item (b) described above has the merit that construction can be performed while confirming an accurate excavation route because the state of the excavation hole tip and the position of the excavation hole tip can be grasped by the inserted TV camera. is there.

  The magnetic exploration device of item (c) described above is a device for exploring foreign matter existing in a construction area in order to grasp the position when a pipe or a pile is present. And since the position of such an existing foreign material can be grasped | ascertained, it can excavate so that it may not interfere with the said foreign material.

  The above-mentioned ground sampling of item (c) is a preliminary process for grasping in advance the properties of the ground to be excavated and enabling proper construction.

  During the operations (a) to (d) described above, jamming or the like does not occur in the case where earth or sand flows in when the tip core portion 3 of the bent boring (hereinafter, the bent boring is referred to as a boring rod) 1 is collected. It is necessary to.

  Therefore, in the illustrated embodiment, the bent boring is performed in the manner shown in FIGS. 1 to 6 so that jamming due to inflow of earth and sand does not occur even when the tip core portion 3 is recovered from the boring rod 1. The tip core portion 3 at the tip is collected to the tuyere side (or the ground side), and the tip core portion 3 is bent and disposed at the tip of the boring again.

  First, FIG. 1 shows a state in which soil G is drilled to a predetermined distance with a flexible boring rod 1, for example.

  The tip 11 of the boring rod 1 has an inclined flat end face 11C, and the correction reaction force plate 2 is attached to the end face 11C so as to extend upward in the drawing from the front end of the end face 11C. It has been.

The boring rod 1 is a so-called “hollow” member, and a hollow portion 13 is provided over its entire length. The tip hollow portion 12 at the tip of the hollow portion 13 is configured to penetrate the end face 11C.
The correction reaction force plate 2 is also formed with a hollow hole 22 as if the tip hollow portion 12 penetrates the reaction force plate 2.
The inner diameter of the tip hollow portion 12 is smaller than the inner diameter of the hollow portion 13.

In FIG. 1, the tip core portion 3 is disposed across the tip hollow portion 12 and the hollow portion 13. The front core portion 3 is configured such that the front surface 3 f thereof is flush with the inclined front surface 21 of the correction reaction force plate 2.
The tip core portion 3 is inserted so as to close the tip hollow portion 12 and the hollow portion 13, and the shape of the tip core portion 3 is complementary to the hollow portion 13 and the tip hollow portion 12. That is, the front portion 31 of the tip core portion 3 has the same diameter as the tip hollow portion 12, and the rear portion 32 of the tip core portion 3 has the same diameter as the hollow portion 13.

A drilled water channel 14 is formed in a portion corresponding to the outer shell side of the hollow end 12 of the boring rod 1. The drilling water channel 14 supplies the drilling water (drilling fluid) that has reached the hollow end 12 of the boring rod 1 to the drilling water discharge port 15 formed near the tip of the boring rod 1.
The direction of the drilling water discharge port 15, more specifically, the injection and injection direction of the drilling water ejected from the drilling water discharge port 15 is the same as the direction in which the correction reaction force plate 2 is facing.

A center hole 33 is formed at the center of the shaft of the tip core portion 3, and the center hole 33 has an opening 33 o on the rear surface 3 r of the tip core portion 3. It is formed to reach the middle of 31.
In the center hole 33, an enlarged diameter portion 34 having an enlarged inner diameter is formed in the vicinity of the opening 33o. The enlarged-diameter portion 34 is formed to hook a lock claw of a collection device (hereinafter, “collection device” is referred to as “collection rod”) 4 described later.

A drilled water passage 35 is formed in the region of the front portion 31 of the front end core portion 3, and one opening of the drilled water passage 35 coincides with the opening of the drilled water channel 14 on the boring rod 1 side. The other opening is open to the center hole 33.
In FIG. 1, reference numeral 100 denotes a drilled borehole, and reference numeral 50 denotes a tuyere (ground side) of the borehole 100.

In the process of FIG. 2 subsequent to the drilling process shown in FIG. 1, the small-diameter portion 42 at the tip of the recovery rod 4 serving as a recovery device is inserted into the opening 33 o of the center hole 33 of the tip core portion 3.
The recovery rod 4 includes a main body portion 41 and a narrow diameter portion 42 having a conical portion 42t at the tip, and the conical portion 42t at the tip of the thin diameter portion 42 is inserted into the center hole 33.

  In a state where the conical portion 42t at the distal end of the small diameter portion 42 of the recovery rod 4 is inserted into the center hole 33, that is, in a state where the recovery rod 4 is engaged with the distal end core portion 3, the distal end core portion 3 and the tuyere Collected on the 50th side (ground side).

When the recovery rod 4 is engaged with the distal end core portion 3, the small diameter portion 42 is provided with a known lock mechanism (not shown). Although not shown, as such a locking mechanism, for example, a claw urged radially outward by a spring or the like protrudes from the outer periphery of the small-diameter portion 42 to expand the center hole 33 of the tip core portion 3. A mechanism that engages with the diameter portion 34 can be employed.
Due to the action of the locking mechanism, the tip core portion 3 is recovered to the ground side without deviating from the recovery rod 4.

  Here, the recovery rod 4 is formed with a fluid channel 43 over its entire length, and the fluid flowing through the fluid channel is ejected from an ejection hole 43n formed at the tip 42t of the recovery rod. Has been.

  As shown in FIG. 3, when the tip core portion 3 is recovered from the tip 11 of the boring rod 1 to the tuyere 50 side by the recovery rod 4, by drilling a drilling fluid or other fluid from the injection hole 43 n, The ejected fluid (arrow J) passes through the center hole 33 and the drilled water passage 35 formed in the tip core portion 3 and is located on the tip side of the tip core portion 3 in the hollow portion 3 of the rod 1 (see FIG. 3 flows into the region on the left side, prevents the generation of negative pressure in the region, and suppresses earth and sand from being sucked into the inside of the rod 1 (the hollow end 12 and the hollow portion 13 of the boring rod 1). .

  4 to 6 show a step of re-installing the tip core portion 3 collected on the ground side through the steps shown in FIGS. 1 to 3 at a predetermined position of the bent boring tip 11.

In FIG. 4, the recovery rod 4 engaged with the tip core portion 3 is reinserted from the tuyere side 50 toward the tip 11 of the boring rod 1. At the time of reinsertion, drilling fluid (water, bentonite) is sprayed from the injection hole 43n at the tip of the recovery rod 4 (arrow J).
Even if the earth and sand flows into the opening of the boring rod tip 11, the flowing earth and sand Ga is opened by the drilling fluid (water, bentonite) injected from the injection hole 43n (the hollow hole of the reaction plate 2 for correction). 22 can be discharged to the outside.

FIG. 5 shows a state where the insertion of the tip core portion 3 into the tip 11 of the boring rod 1 is completed.
Here, as shown in FIG. 4, even if the earth and sand flows into the opening of the boring rod tip 11, the earth and sand are discharged by the drilling fluid (water, bentonite) injected from the injection hole 43n, so that jamming occurs. The tip core portion 3 can be installed at an appropriate position at the tip 11 of the boring rod 1 without occurring.

FIG. 6 shows a state in which the recovery rod 4 is removed from the tip core portion 3, the recovery rod 4 is pulled out to the ground side, and drilling is started again by the boring rod 1.
In the lock mechanism (not shown) described in relation to FIG. 2, for example, a lock claw (not shown) is stored in the recovery rod 4 and the engagement of the recovery rod 4 with the tip core portion 3 is released.

Here, the cutting fluid is required to have the following properties: (1) A lubrication effect that reduces the resistance to rotation is necessary (water and bentonite have seen this condition).
(2) It is necessary to have an effect of cooling the tip (blade edge) of the excavation site (water and bentonite have seen this condition).
(3) In order to discharge the drilling earth and sand, it is desirable that the drilling fluid has a certain specific gravity (specific gravity to the extent that the drilling earth floats: 1.02 to 1.05). In this respect, bentonite is desirable.
(4) In order to prevent water loss, it is necessary to form a film on the wall surface of the drilled hole (bentonite (muddy water) is suitable because it forms a film).

  Although not clearly shown in FIG. 1, when bentonite is used as the drilling fluid, bentonite (a drilling liquid) is formed on the inner wall surface of the hollow rod (boring rod) 1 of the bent boring simultaneously with the drilling process. The thin film (about 70 μm) is formed to prevent the earth and sand flowing in from the boring rod tip 11 from adhering to the inner wall surface.

As shown in FIG. 7, in the case of a curved excavation path, there is a possibility that the distal end core portion 3 is bent and comes into contact with the inner wall surface 13f of the rod. If the tip core portion 3 and the rod inner wall surface 13f are in surface contact, jamming will not occur even if there is some earth and sand, but if earth and sand are present at the point contact point, jamming is likely to occur.
However, if bentonite is used as the cutting fluid, a film is formed on the inner wall surface 13f of the boring rod, so that the inflow soil is always separated from the inner wall surface 13f of the rod (the inner wall surface 13f and the inflow soil sand). Since the bentonite film is interposed between them, the inflow earth and sand are washed when the tip core portion 3 is inserted, and it is completely prevented that the inflow earth and sand remain at the point contact point. Such jamming can be prevented.
The relationship between the outer diameter E and length L of the tip core portion 3 shown in FIG. 7, and the inner radius D of the hollow portion 13 of the boring rod 1 and the curvature radius R of the locus of the inner diameter center point will be described later.

  Even when water is used as the cutting fluid, the inflow earth and sand are washed when the tip core portion 3 is inserted, so that the inflow earth and sand are completely prevented from remaining at the point contact locations, and jamming can be prevented.

That is, as the drilling fluid, bentonite, which is viscous and forms a film, is desirable.
Of course, it is possible to use high-pressure water as a drilling fluid.

Due to the discharged soil (annular space between the inner wall surface of the borehole 100 and the outer peripheral surface of the boring rod 1) and the propulsive force of the boring rod 1, the amount of bentonite injected (the discharge flow rate of the pump on the ground side) To control. The specific injection volume is case-by-case.
The control of the bentonite injection amount is performed, for example, based on existing data stored in a database or the experience of a construction manager.
The same applies when the drilling fluid is water.

  Although not shown, the correction reaction force is such that the earth and sand flowing into the opening of the tip 11 of the boring rod 1 is located outside the boring rod 1 when the tip core portion 3 is recovered or reinserted. The plate 2 and a sleeve tube 5 to be described later are slightly pulled to the ground side to displace the relative position with respect to the mechanism even if the earth and sand itself does not move, so that the earth and sand are located outside the mechanism. May be.

  Although not shown, instead of filling the drilling fluid, the rod 1 may be filled with bubbles. In that case, at the end of the excavation process in FIG. 1, bentonite and foam are replaced, and a measuring instrument or the like is taken in and out in the presence of the foam. Then, when the tip core portion 3 is reinserted, for example, when the measuring instrument is removed from the boring rod 1, the bubbles of the hollow rod can be replaced with bentonite.

Next, each of the above-described operations (a) to (d), that is, (a) after excavating a predetermined region by bending boring, inserting a sleeve tube equipped with a packer and injecting a solidified material or other chemicals,
(B) Inserting a TV camera at the tip of a curved boring to check the ground condition,
(C) Inserting a magnetic exploration device at the tip of a bent boring to conduct magnetic exploration;
(D) Work to collect the sample soil by inserting a sampling device at the tip of the bent boring,
Will be described in detail below.

  First, after excavating a predetermined region by the work (a), that is, by bending boring (boring rod) 1, a sleeve tube equipped with a packer is inserted to inject a solidified material or other chemicals with reference to FIGS. To explain.

In FIG. 8, a predetermined region is drilled in a state where the distal end portion 11 of the hollow boring rod 1 is closed by the distal end core portion 3.
Next, the recovery rod 4 is inserted from the tuyere (ground) 50 side, and the distal end portion 42 of the recovery rod 4 is engaged with the center hole 33 of the distal core portion 3 (FIG. 9).

In FIG. 10, the recovery rod 4 with the tip core portion 3 engaged is extracted to the tuyere 50 side. In other words, the tip core portion 3 is removed from the tip of the boring rod 1.
At that time, in the same manner as described with reference to FIG. 3, the drilling fluid is ejected from the tip core portion 3, so that negative pressure is generated inside the boring rod 1 and the sediment flows in advance. To prevent.

In FIG. 11, the sleeve tube 5 is inserted into the hollow portion 13 of the boring rod 1 from the tuyere 50 side, and the sleeve tube 5 is penetrated further forward than the tip portion 11 of the boring rod 1.
At that time, as described with reference to FIG. 4, the drilling fluid is ejected from an unillustrated ejection mechanism at the tip of the sleeve tube 5, and the sediment flowing into the hollow portion 13 of the boring rod 1 is removed.

After allowing the sleeve tube 5 to penetrate forward from the tip 11 of the boring rod 1, the boring rod 1 is extracted to the ground side (FIG. 12). In addition, in FIG. 12, the state after the boring rod 1 is extracted is drawn.
In FIG. 13, the packer 6 is inserted into the sleeve tube 5, and the inserted packer 6 is pushed to the front end of the sleeve tube 5.

  In FIG. 14, for example, the solidified material K is filled in the bored hole 100 that has been excavated. In FIG. 15, the pair of expansion members 61 and 61 of the packer 6 are filled with the solidified material K. It expands and the chemical | medical solution N is ejected from the injection hole (spout location of the chemical | medical solution N) formed between the pair of expansion members 61 and 61 (injection of the 1st step). The chemical solution N penetrates to the soil G side.

  When the first-stage injection is completed, as shown in FIG. 16, the sleeve tube 5 and the packer 6 are pulled out to the tuyere 50 side by a predetermined amount, and the second-stage chemical solution is injected at that position. Thereafter, the chemical solution is sequentially injected toward the tuyere 50 side.

  Next, the operation (b), that is, the operation of inserting a TV camera at the tip of the boring rod 1 and confirming the ground condition will be described with reference to FIGS.

The description of the steps of FIGS. 17 to 19 in FIGS. 17 to 21 is the same as that of FIGS.
Here, in the process of FIG. 19, as described with reference to FIG. 3, the drilling fluid is ejected from the tip core portion 3, and negative pressure is generated inside the boring rod 1, so Prevent inflow in advance.

In FIG. 20, the recovery rod 4 with the TV camera 7 attached to the tip is inserted into the hollow portion 13 of the boring rod 1 from the tuyere 50 side from the tuyere 50 side, and the TV camera 7 is inserted into the tip of the boring rod 1. It is arranged in front of 11.
When the recovery rod 4 with the TV camera 7 attached to the tip is inserted, as shown in FIG. 4, the drilling fluid is jetted from a jet mechanism (not shown) at the tip of the sleeve tube 5, so that the hollow portion of the boring rod 1 The earth and sand which flowed into 13 is excluded.

  After the TV camera 7 is pushed forward from the front end portion 11 of the boring rod 1, the ground condition is confirmed using the TV camera 7 in FIG.

  Next, the operation (c), that is, the operation for performing the magnetic exploration by inserting the magnetic exploration device at the tip of the boring rod 1 will be described with reference to FIGS.

22 to 28, the description of the steps of FIGS. 22 to 24 is the same as that of FIGS.
Here, in the process of FIG. 24, as described with reference to FIG. 3, the drilling fluid is injected from the tip core portion 3, and negative pressure is generated inside the boring rod 1 so that the earth and sand are generated. Prevent inflow in advance.

In FIG. 25, a vinyl chloride pipe 8 is inserted into the hollow portion 13 of the boring rod 1 from the tuyere 50 side, and the vinyl chloride pipe 8 is penetrated further forward than the tip portion 11 of the boring rod 1. .
When inserting the pipe 8 made of vinyl chloride into the hollow portion 13 of the boring rod 1, as described with reference to FIG. Sediment that has flowed into the hollow portion 13 of the boring rod 1 is removed.

  In FIG. 26, after the pipe 8 made of vinyl chloride is penetrated to the front of the front end portion 11 of the boring rod 1, the boring rod 1 is extracted to the ground side and collected.

  In the next FIG. 27, the recovery rod 4 with the magnetic exploration device 9 attached to the tip is inserted from the tuyere 50 side, and the magnetic exploration device 9 is arranged at the tip of the vinyl chloride pipe. In FIG. 9 starts magnetic exploration.

  Next, with respect to the above-described operation (d), that is, the sampling soil is sampled by inserting the sampling device into the tip of the bent boring, and the collected sampling soil and the sampling device are recovered, refer to FIGS. I will explain.

29 to 34, the description of the steps of FIGS. 29 to 31 is the same as that of FIGS.
In the process of FIG. 31, in the same manner as described with reference to FIG. 3, the drilling fluid is ejected from the tip core portion 3, and negative pressure is generated inside the boring rod 1 so that earth and sand flows. Prevent in advance.

In the next FIG. 32, the recovery rod 4 with the sampling device 10 attached to the tip is inserted from the tuyere 50 side, and the sampling device 10 is disposed at the tip 11 of the boring rod 1.
When the sampling device 10 is inserted, the drilling fluid is jetted from the jet mechanism (not shown) at the tip of the sleeve tube 5 to remove the earth and sand flowing into the hollow portion 13 of the boring rod 1 in the same manner as described with reference to FIG. Exclude.

  In FIG. 33, the sampling soil Gs in front of the front end portion 11 of the boring rod 1 (left side in FIG. 33) is collected by the sampling device 10, and the collected sampling soil Gs and the sampling device 10 are collected on the ground side (FIG. 34). ).

  Again, in the work described with reference to FIGS. 8 to 34, that is, the sleeve tube 5 injection in the above-described work (a), the TV camera 7 is inserted in the work (b), and the magnetic exploration device 9 is inserted in the work (c). In the operation (d), when the sampling device 10 is inserted, the "distal core portion removal" operation (FIGS. 10, 19, 24, and 31) is shown in FIG. Similarly to the above, water, bentonite, or the like is jetted to prevent negative pressure from being generated near the opening 22.

  In addition, the “sleeve tube insertion” operation (FIG. 11) in the sleeve tube 5 injection of item (a), the “TV camera insertion” operation (FIG. 20) in the TV camera 7 insertion of item (b), and the magnetism of item (c). In the "insertion of the vinyl chloride pipe 8" work in the exploration device insertion (Fig. 25) and the "sampling device insertion" operation in the sampling device 10 insertion of the item (d) (Fig. 32), the sediment flowing in from the opening 22 is removed. In order to do so, water, bentonite, or the like is sprayed in the vicinity of the opening 22 as shown in FIG.

In each operation described with reference to FIGS. 1 to 34, in order to prevent the tip core portion 3 and the measuring instrument from being caught in the boring rod 1 and becoming incapable of moving, the longitudinal length of the tip core portion 3 or the measuring instrument etc. Regarding the direction length L and the outer diameter E, it is necessary to limit the numerical range as shown below.
In FIG. 7, when the radius of curvature at the axial center of the boring rod 1 is R, the inner diameter dimension is D, and the outer diameter of the tip core 3 or measuring instrument is E, the inserted angle is θ. The length L of the tip core 3 or the measuring instrument is expressed by the following formula L <(2R + D) sinθ
It is necessary to be in the range.

The length L of the tip core portion 3 is determined in advance, but if the outer diameter E of the tip core portion 3 or measuring instrument is not determined, the center of curvature of the boring rod 1 to the outer periphery of the tip core portion 3 is determined. If the distance of C is C, the outer diameter E of the tip core portion 3 or the measuring instrument must satisfy the following equation.
E <C-R + D / 2

The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention.
For example, it is possible to accurately measure the excavation path by allowing the gyro to pass through the cutting fluid channel without bending the tip core portion from the tip of the boring.

In embodiment of this invention, the initial state figure which shows the aspect which collect | recovers the front-end | tip core part of a bending boring tip to a tuyere side. The state figure which showed the state process of mounting | wearing a front-end | tip core part with a collection | recovery apparatus. The state figure which showed the state process which discharges the fluid for a negative pressure prevention. The process figure which showed the state which reinserts the collection | recovery rod which engaged the front-end | tip core part toward the front-end | tip of a boring rod among the processes which install the collect | recovered front-end | tip core part again in the predetermined location of a boring rod front-end | tip. The process figure which showed the state which insertion to the boring rod front-end | tip of a front-end | tip core part was completed. The process figure which showed the state which removes a collection | recovery rod from a front-end | tip core part, the collection | recovery rod is pulled out on the ground side, and is going to start a drilling with a boring rod again. Explanatory drawing about the relationship between the outer diameter and length of a front-end | tip core part, and the curvature radius of the locus | trajectory of the internal diameter of a hollow part of a boring rod, and an internal diameter center point. After drilling a predetermined area by bending boring, the tip of the boring rod is blocked by the tip core in a series of steps of inserting a sleeve tube equipped with a packer and injecting solidified material or other chemicals The process figure which showed the process of excavating a predetermined area | region. The process figure which showed the process of making the collection | recovery rod inserted from the ground side engage with the front-end | tip core part of the front-end | tip part of a boring rod. The process figure which showed the process of inserting a collection | recovery rod from a tuyere side and collect | recovering a front-end | tip core part to the ground side. The process figure which showed the process which penetrates a sleeve pipe | tube to the front rather than the front-end | tip part of a boring rod. Process drawing which showed the process of extracting a boring rod to the ground side. The process figure which showed the process of pushing in the inserted packer to the front-end part of a sleeve pipe | tube. The process figure which showed the process of filling the solidification material K inside a boring hole. The process figure which showed injection | pouring (1st step injection | pouring) to the inside of a boring hole of a chemical | medical solution. Process drawing which showed injection | pouring of the 2nd step | paragraph of a chemical | medical solution. Shows the process of excavating a predetermined area with the tip core part of the boring rod blocked by the tip core part in a series of steps to check the ground condition by inserting a TV camera at the tip of the boring rod. Process diagram. The process figure which showed the process of inserting a collection | recovery rod from a tuyere side and engaging a collection | recovery rod with a front-end | tip core part. Process drawing which showed the process of collect | recovering a front-end | tip core part to the ground side. The process figure which showed the process which inserts the collection | recovery rod with which the TV camera was mounted | worn at the front-end | tip from the tuyere side, and arrange | positions TV camera ahead of the front-end | tip part of a boring rod. The confirmation process figure of ground condition using a TV camera. Shown is a step of excavating a predetermined area in a state where the tip portion of the boring rod is blocked by the tip core portion in a series of steps of performing the magnetic survey by inserting a magnetic probe device at the tip of the boring rod. Process chart. The process figure which showed the process of inserting a collection | recovery rod from a tuyere side and engaging a collection | recovery rod with a front-end | tip core part. Process drawing which showed the process of collect | recovering a front-end | tip core part to the ground side. The process figure which showed the process which penetrates the pipe made from a vinyl chloride to the front rather than the front-end | tip part of a boring rod. Process drawing which showed the process of extracting and recovering a boring rod to the ground side. The process figure which showed the process of arrange | positioning a magnetic exploration apparatus in the front-end | tip part of a vinyl chloride pipe. The process figure which showed the process of starting a magnetic exploration with a magnetic exploration apparatus. A sampling device is inserted into the tip of a bent boring, sampling soil is collected, and the tip of the boring rod is blocked by the tip core in a series of operations for collecting the collected sampling soil and sampling device. The process figure which showed the process of excavating a predetermined area | region. The process figure which showed the process of inserting a collection | recovery rod from a tuyere side and engaging a collection | recovery rod with a front-end | tip core part. Process drawing which showed the process of collect | recovering a front-end | tip core part to the ground side. A sampling device is inserted into the tip of a bent boring, sampling soil is collected, and the sampling device is collected at the tip of the boring rod in a series of steps for collecting the collected sampling soil and sampling device. Process diagram. A sampling device is inserted into the tip of the bent boring, sampling soil is collected, and the sampling soil in front of the tip of the boring rod is collected by the sampling device in a series of steps of collecting the collected sampling soil and the sampling device. Process drawing which showed the process to extract | collect. The process figure which showed the process which inserts a sampling apparatus in the front-end | tip of a curved boring, collects sampling soil, and collect | recovers the collected sampling soil and sampling apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bending-boring rod / boring rod 2 ... Reaction force plate 3 for correction | amendment ... Core part 4 ... Recovery rod 5 ... Sleeve tube 6 ... Packer 7 ... TV Camera 8 ... PVC pipe 9 ... Magnetic exploration device 10 ... Sampling device 11 ... Tip 12 ... Space in the rod 13 ... Hollow portion 14 in the rod ... Drilling Fluid flow path 15 ... Drilling water discharge port 33 ... Center hole 50 ... Down tuyere 100 ... Drilling hole

Claims (3)

 In a drilling method in which a boring hole is drilled using a flexible hollow rod provided with a drilling means and a drilling direction control means at the tip, the hollow portion inside the rod has a flow path for drilling fluid. A closing member configured to close the rod tip is configured to be detachable, and a drilling step of drilling a ground by injecting a drilling fluid from the drilling means, and the closing member to the hollow The closing member collecting step for removing the rod from the rod tip and collecting it through the hollow portion inside the rod, and inserting the equipment necessary for the work after drilling into the hollow portion inside the rod and moving to the tip of the hollow rod A drilling method characterized by comprising an insertion step.  The drilling method according to claim 1, wherein, in the inserting step, a drilling fluid is injected into a hollow space inside the rod when a device necessary for work after drilling is inserted.  In the closing member collecting step, when the closing member is removed from the tip of the hollow rod and collected through the hollow portion inside the rod, the rod is moved to a region closer to the rod tip than the closing member in the hollow space inside the rod. The drilling method according to claim 1, wherein the drilling fluid is jetted.

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