Check valve removal jig, check valve removal device, and check valve removal method

Abstract

To propose a check valve removal jig, a check valve removal device, and a check valve removal method capable of recovering a check valve installed in a grout hole.SOLUTION: A check valve removal jig 30 including a cylindrical main body 31 having an outer diameter smaller than an inner diameter of a grout hole 11, a plurality of cutting tips 32, 32, . . . provided at a tip of the main body 31, a check valve holding portion 33 provided on an inner surface of the main body 31, and a connecting portion 34 formed at a base end of the main body 31 is used. The cutting tip 32 cuts an outer edge portion of a check valve 12 when the main body 31 is rotated by the rotational force applied by rotational force applying means connected to the connecting portion 34. The check valve holding portion 33 holds the check valve 12 whose outer edge portion has been cut and taken into the main body 31 so that it does not slip out from the main body 31.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a check valve removal jig, a check valve removal device, and a check valve removal method for removing a check valve provided in a grout hole of a segment.

Background Art

[0002] In the shield method, a lining is formed by continuously arranging segment rings formed by combining a plurality of segments in the excavation direction. The excavation of the ground by a shield tunneling machine is performed in a form including an over-excavated portion so as to have a cross-section larger than that of the shield tunneling machine and the segment ring. It is necessary to fill the gap (the back surface of the segment) between the lining formed by over-excavation and the ground with a backfill material to suppress the collapse of the ground. The injection of the backfill material to the back surface of the segment is performed from a grout hole formed in the segment. At this time, a check valve for preventing the backflow during the injection of the backfill material is generally provided in the grout hole (see, for example, Patent Document 1). When performing ground improvement around the tunnel or soil investigation, if the grout hole is used, there is no need to form a new through hole in the tunnel lining. However, since a check valve is provided in the grout hole, when performing ground improvement or soil investigation using the grout hole, it is necessary to remove the check valve. On the other hand, since the backfill material filled on the back side is fixed to the check valve, it is difficult to remove it from the grout hole. In addition, when performing ground improvement or soil investigation, it is possible to drill a hole including the check valve, but there is a risk that the cutting pieces of the check valve remaining in the ground may affect the ground improvement or investigation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The object of this invention is to propose a check valve removal jig, a check valve removal device, and a check valve removal method that enable the recovery of check valves installed in grout holes. [Means for solving the problem]

[0005] To solve the aforementioned problems, the check valve removal jig of the present invention comprises a cylindrical main body having an outer diameter smaller than the inner diameter of the grout hole, a plurality of cutting tips provided at the tip of the main body, a check valve holding portion formed on the inner surface of the main body, and a connecting portion formed at the base end of the main body. The main body rotates due to a rotational force applied by a rotational force applying means connected to the connecting portion, and the cutting tips cut the outer edge portion of the check valve as the main body rotates. The check valve is then separated from the grout hole. The check valve holding part is Separated from the aforementioned grout hole The check valve, which is incorporated into the main body, is held in place so as not to come out of the main body. Furthermore, the check valve removal device of the present invention comprises a valve attached to a grout hole in a segment, a prepender connected to the valve, a rod inserted through the prepender and the valve, a rotational force applying means (for example, a drilling device) for applying rotational force to the rod, and the check valve removal jig attached to the tip of the rod. Furthermore, the method for removing a check valve using this check valve removal jig includes the steps of: attaching the valve and prepender to the grout hole of the segment; inserting the check valve removal jig attached to the tip of a rod into the grout hole through the prepender and the valve; and rotating the rod and pushing the rod in. In this way, the outer edge portion of the check valve installed in the grout hole is cut away, and the remaining portion of the check valve is taken into the main body.

[0006] With this check valve removal jig, check valve removal device, and check valve removal method, the check valve with its periphery cut off is taken into the main body and recovered, so the check valve and its cuttings (fragments of the check valve) are not left behind in the grout hole or underground. Therefore, in ground improvement or soil investigation using the grout hole after the check valve has been removed, it is possible to prevent the check valve and its cuttings from interfering with ground improvement or investigation results. Since the check valve is cut using a cutting tip, it is possible to recover the check valve even if it is unable to rotate due to backfill material (grout, etc.) adhering to it.

[0007] The check valve retaining part has the function of holding the check valve, which is taken into the main body, so that it does not come out. For example, multiple annular brushes or annular rubber materials can be used, which are arranged in parallel along the axial direction of the main body. Furthermore, when the check valve holding portion is formed using brushes, arranging brushes with different bristle lengths alternately makes it easier to take the check valve into the main body and also makes it difficult for the check valve to come out. Furthermore, a rectangular carbide tip can be used as the cutting tip. The rectangular cutting tip should be inclined relative to the inner surface of the main body when viewed from the side, and fixed to the main body in a orientation along the radial axis centered on the central axis when viewed from the front. In this way, the corners of the cutting tip bite into the check valve, allowing for efficient cutting. Also, because the cutting tip is inclined relative to the inner surface of the main body, the check valve with its cut edges is easily guided into the interior of the main body. [Effects of the Invention]

[0008] According to the check valve removal jig, check valve removal device, and check valve removal method of the present invention, check valves installed in grout holes can be recovered, and as a result, the grout holes can be used for ground improvement and soil investigation around the tunnel. [Brief explanation of the drawing]

[0009] [Figure 1]It is a cross-sectional view showing an overview of the soil investigation status from inside the shield tunnel. [Figure 2] It is a view showing a grout hole, where (a) is a cross-sectional view and (b) is a view seen from arrow A in (a). [Figure 3] It is a cross-sectional view showing a check valve removal device. [Figure 4] It is a view showing a check valve removal jig, where (a) is a side view and (b) is a cross-sectional view. [Figure 5] It is a view showing a check valve removal jig, where (a) is a view seen from arrow B in Figure 4 and (b) is a view seen from arrow C in Figure 4. [Figure 6] It is a cross-sectional view showing a grout hole water stop device. [Figure 7] It is a view showing a water stop plug, where (a) is a view seen from arrow D in Figure 6, (b) is a view seen from arrow E in Figure 6, and (c) is a view seen from arrow F in Figure 6. [Figure 8] It is an enlarged cross-sectional view showing a locking portion. [Figure 9] It is a flowchart showing the procedure of the soil investigation method of this embodiment. [Figure 10] It is a cross-sectional view showing a cap removal process. [Figure 11] It is a cross-sectional view showing an instrument attachment process. [Figure 12] It is a cross-sectional view showing a check valve removal process, where (a) is when the check valve removal jig is installed, (b) is when the check valve is cut, (c) is when the cutting of the check valve is completed, and (d) is when the check valve removal jig is recovered. [Figure 13] It is a cross-sectional view showing the working status of a sample collection process. [Figure 14] It is a cross-sectional view showing a temporary water stop process, where (a) is when the water stop plug is inserted and (b) is when the water stop plug is expanded. [Figure 15] It is a cross-sectional view showing an instrument removal process. [Figure 16] It is a cross-sectional view showing a cap restoration process.

Embodiments for Carrying Out the Invention

[0010] In this embodiment, a method for collecting a sample (boring core) from inside a shield tunnel to investigate the soil quality around the tunnel will be described. Fig. 1 shows an overview of the soil investigation situation. The sample collection from the ground G around the tunnel T utilizes the grout hole 11 of the segment 1. The segment 1 of this embodiment is a steel segment, and the grout hole 11 is erected on the skin plate of the segment 1. The soil investigation using the grout hole 11 is performed by pressing the sampler 2 into the ground from the grout hole 11 and collecting the sample taken into the sampler 2. In this embodiment, the drilling device 21 is used to press the sampler 2 into the ground G.

[0011] Fig. 2 shows the grout hole 11. As shown in Figs. 2(a) and (b), a check valve 12 for preventing the backflow of the grout material during backfill injection is installed in the grout hole 11. Therefore, when conducting a soil investigation using the grout hole 11, it is necessary to remove the check valve 12. On the other hand, since the check valve 12 has grout attached to it, it is difficult to recover it manually. Also, after the soil investigation, for the grout hole 11, since the check valve 12 has been removed, it is necessary to perform water stoppage to prevent the inflow of soil and sand from the grout hole 11 after the sampler 2 has been removed. In this embodiment, the check valve removal device 3 is used to remove (recover) the check valve 12 installed in the grout hole 11, and the grout hole water stoppage device 4 is used to perform water stoppage after the soil investigation.

[0012] Fig. 3 shows the check valve removal device 3. As shown in Fig. 3, the check valve removal device 3 includes a valve 5 attached to the grout hole 11 of the segment 1, a pre-pender 6 connected to the valve 5, a rod 7 inserted through the pre-pender 6 and the valve 5, a rotational force applying means (not shown) for applying a rotational force to the rod 7, and a check valve removal jig 30 attached to the tip of the rod 7.

[0013] Valve 5 has a hollow member fixed to the end of the grout hole 11. Both ends of valve 5 have openings with a diameter larger than the inner diameter of the grout hole 11, allowing the check valve removal tool 30 to be inserted. An opening / closing member (not shown) is provided inside valve 5, and the space can be opened and closed by operating the handle 51. The prepender 6 is a cylindrical member connected to the opening on the base end side of the valve 5. The prepender 6 has an inner diameter through which the check valve removal jig 30 and the rod 7 can be inserted. The prepender 6 is also provided with a water-stopping means 61 that seals the gap between the outer surface of the rod 7 and the inner surface of the prepender 6, thereby suppressing the inflow of soil and sediment from the grout hole 11 and the backflow of treated water during soil investigation after the check valve 12 has been removed. Rod 7 extends from a rotational force application means (such as a drilling device) not shown. A connecting member 71 is fixed to the tip of rod 7, which engages with the connection portion 34 of the check valve removal jig 30.

[0014] The check valve removal tool 30 is for removing the check valve 12 installed in the grout hole 11 of segment 1. The check valve removal tool 30 is shown in Figures 4 and 5. As shown in Figures 4(a) and (b), the check valve removal tool 30 comprises a main body 31, a plurality of cutting tips 32, 32, ..., a check valve holding portion 33 provided on the inner surface of the main body 31, and a connecting portion 34 formed at the base end of the main body 31. As shown in Figures 3 and 4(a), the main body 31 is a cylindrical member having an outer diameter smaller than the inner diameter of the grout hole 11, and is insertable into the grout hole 11. The tip of the main body 31 is open. Multiple cutting tips 32, 32, ... are fixed to the tip of the main body 31. In addition, a connecting portion 34 is formed at the base end of the main body 31, which is connected to a rod 7 extending from the rotational force applying means. The rotational force of the rotational force applying means is applied to the connecting portion 34 of the main body 31 via the connecting member 71 of the rod 7. Furthermore, as shown in Figure 4(b), a check valve holding portion 33 is provided on the inner surface of the main body 31.

[0015] The cutting tip 32 cuts the outer edge of the check valve 12 as the main body 31 rotates due to the rotational force applied by the rotational force applying means. The cutting tip 32 in this embodiment is a rectangular parallelepiped metal member, as shown in Figures 4(b) and 5(a). Multiple cutting tips 32, 32, ... are provided at intervals in the circumferential direction at the tip of the main body 31, as shown in Figure 5(a). Each cutting tip 32 is inclined (for example, 10°) with respect to the central axis of the main body 31 in a side view, as shown in Figure 4(a). The cutting tip 32 is also inclined (for example, 45°) with respect to the inner surface of the main body 31, as shown in Figure 4(b). Furthermore, the cutting tip 32 is fixed to the main body 31 in a front view, as shown in Figure 5(a), in a direction along the radial direction of the main body 31 (direction along the radial direction of the main body 31) with respect to the central axis.

[0016] The check valve holding portion 33 holds the check valve 12, which has its outer edge cut off and is incorporated into the main body portion 31, to prevent it from coming out of the main body portion 31. As shown in Figures 4(b) and 5(b), the check valve holding portion 33 of this embodiment consists of a plurality of annular brushes 33a, 33b arranged in parallel along the axial direction of the main body portion 31. The plurality of annular brushes 33a, 33b arranged in parallel are arranged alternately, with different bristle lengths.

[0017] The connecting portion 34 is a nut fixed to the base end of the main body portion 31. As shown in Figures 4(a) and (b), the main body portion 31 in this embodiment has a bottom, and the connecting portion 34 is fixed to the outer surface (base end surface) of the bottom plate 35 of the main body portion 31. As shown in Figure 3, the connecting portion 34 engages with a connecting member 71 fixed to the tip of the rod 7 and transmits the rotational force of the rotational force applying means transmitted via the rod 7 to the main body portion 31. The main body portion 31 rotates due to the rotational force applied via the connecting portion 34, and the outer edge portion of the check valve 12 is cut by the cutting tip 32.

[0018] Figures 6 and 7 show the grout hole sealing device 4. As shown in Figure 6, the grout hole sealing device 4 comprises a valve 5 attached to the grout hole 11 of segment 1, a prepender 6 connected to the valve 5, a rod 7 inserted through the prepender 6 and the valve 5, and a sealing plug 40 attached to the tip of the rod 7. The valve 5, prepender 6, and rod 7 are the same as those used in the check valve removal device 3. The connecting member 71 of the rod 7 shall be appropriately changed to a member that can engage with the water stop plug 40 (movement mechanism 44).

[0019] As shown in Figure 6, the water-stopping plug 40 is installed in the grout hole 11 of segment 1 to stop water from entering the grout hole 11. The water-stopping plug 40 comprises a water-stopping member 41 that expands laterally (increases in diameter) due to pressure from the front and rear, a pressing member 42 attached to the front of the water-stopping member 41, a retaining member 43 attached to the rear of the water-stopping member 41, and a moving mechanism 44 that moves the pressing member 42 forward and backward relative to the retaining member 43. As shown in Figures 6 and 7(b), the water-stopping member 41 is made of an elastic cylindrical member with a through hole 41a formed in the center. The water-stopping member 41 in this embodiment is made of an annular rubber material. Normally, the water-stopping member 41 has an outer diameter less than or equal to the inner diameter of the grout hole 11, and expands in diameter laterally (in the diametrical direction of the grout hole 11) when pressure is applied from the front and back (axial direction of the grout hole 11). The water-stopping member 41 may also be a hollow annular member.

[0020] As shown in Figures 6 and 7(a), the pressing member 42 is a circular plate (for example, a steel plate) attached to the front surface of the water-stopping member 41. The pressing member 42 has an outer diameter smaller than the inner diameter of the grout hole 11. The pressing member 42 is in close contact with the water-stopping member 41 when pressed against it. The pressing member 42 may be fixed to the water-stopping member 41 if necessary. The retaining member 43 is a plate (e.g., a steel plate) attached to the rear surface of the water-stopping member 41, as shown in Figures 6 and 7(c). In this embodiment, the retaining member 43 has a cross shape in front view, formed by the combination of four plate pieces 43a, 43a, ..., but the retaining member 43 may also be circular. A through hole is formed in the center of the retaining member 43, and the moving mechanism 44 (bolt 46) is configured to be inserted through it. A locking portion 45 is formed at the tip of each plate piece 43a of the retaining member 43, which can engage with the threads of the female screw 13 of the grout hole 11. The locking portion 45 is a metal piece integrally formed on the outer edge of the retaining member 43 (the tip of the plate piece 43a). Figure 8 shows the locking portion 45. As shown in Figure 8, the locking portion 45 is curved in an arc shape in cross-section, protruding outward from the outer edge of the retaining member 43 (towards the inner wall side of the grout hole 11) and extending backward (towards the tunnel interior). The tip of the locking portion 45 engages with the female thread 13 of the grout hole 11 by fitting into the groove of the female thread 13. This prevents the water-stopping plug 40 inserted into the grout hole 11 from coming out. The retaining member 43 is pressed tightly against the water-stopping member 41. The retaining member 43 may be fixed to the water-stopping member 41 if necessary.

[0021] As shown in Figure 6, the moving mechanism 44 includes a bolt 46 fixed to the pressing member 42 and a nut 47 screwed onto the bolt 46 on the rear surface of the pressing member 43. The bolt 46 is a so-called threaded rod, with one end fixed (welded) to the inner surface (the side facing the tunnel cavity) of the pressing member 42, and the other end screwed into the nut 47. The bolt 46 passes through the through hole 41a of the water-stopping member 41 and the through hole of the retaining member 43. As shown in Figure 6, the nut 47 is screwed onto a bolt 46 that passes through the water-sealing member 41 and the retaining member 43. The nut 47 engages with a connecting member 71 fixed to the tip of the rod 7 and rotates due to the rotational force of the rotational force applying means transmitted via the rod 7. As the nut 47 rotates, the bolt 46 moves axially, causing the pressing member 42 to be pulled towards the retaining member 43. This applies a pressing force in the front-rear direction to the water-sealing member 41, causing the water-sealing member 41 to expand in diameter and come into contact with the inner surface of the grout hole 11, thereby enabling water-sealing of the grout hole 11.

[0022] The following describes a soil investigation method using the grout hole 11. Figure 9 shows the procedure for the soil investigation method. As shown in Figure 9, the ground improvement method includes a cap removal step S1, an equipment installation step S2, a check valve removal step S3, a sample collection step S4, a temporary water stop step S5, an equipment removal step S6, and a cap restoration step S7. The cap removal process S1 is the process of removing the cap 14 attached to the grout hole 11, as shown in Figure 10. Since the cap 14 is screwed onto the female thread 13 of the grout hole 11, it can be removed by rotating it. A check valve 12 is installed inside the grout hole 11.

[0023] The fixture installation process S2 is the process of installing the valve 5 and prepender 6 into the grout hole 11, as shown in Figure 11. The valve 5 is installed into the grout hole 11 via an installation sleeve 52 that is installed to cover the opening of the grout hole 11. In this embodiment, the installation sleeve 52 is configured to be fixed to the grout hole 11 by screwing the sleeve body 52b into a wedge ring 52a that is arranged around the grout hole 11. The prepender 6 is installed on the end of the valve 5 opposite to the grout hole 11.

[0024] The check valve removal process S3 is the process of removing the check valve 12 installed in the grout hole 11. As shown in Figure 9, the check valve removal process S3 comprises a device insertion process S31, a cutting process S32, and a device retrieval process S33. The check valve 12 is removed using a check valve removal jig 30. Figure 12 shows the work status of the check valve removal process. The device insertion step S31 is the step of inserting the check valve removal jig 30 into the grout hole 11, as shown in Figure 12(a). The check valve removal jig 30 is inserted into the grout hole 11 through the prepender 6 and valve 5 with the rod 7 (connecting member 71) attached to the tip (see Figure 3), and the cutting tip 32 is brought into contact with the check valve 12.

[0025] As shown in Figures 12(b) and (c), cutting process S32 is a process of cutting and removing the check valve 12 using the check valve removal jig 30. In cutting process S32, the check valve 12 is cut by rotating the rod 7 while the cutting tip 32 is in contact with the check valve 12, and by pushing the rod 7 in. As shown in Figure 12(a), the outer edge of the check valve 12 installed in the grout hole 11 is cut by the rotating check valve removal jig 30. As the rod 7 is pushed in while the outer edge of the check valve 12 is being cut, the remaining part of the check valve 12, whose outer edge has been cut, is taken into the main body 31, as shown in Figure 12(c). The check valve 12 taken into the main body 31 is held in place by the check valve holding part 33. The device retrieval process S33 is the process of retrieving the check valve removal jig 30, as shown in Figure 12(d). The check valve removal jig 30 is retrieved from the grout hole 11 by pulling out the rod 7 (connecting member 71). At this time, the check valve 12 (cutting piece) that has been taken into the main body 31 is held by the check valve holding part 33 while entangled with the brushes 33a and 33b, and is therefore retrieved together with the check valve removal jig 30.

[0026] The sample collection process S4 is a process of collecting a sample from the ground G using the grout hole 11. Figure 13 shows the working status of the sample collection process. As shown in Figure 13, the sample is collected by pressing the sampler 2 into the ground through the grout hole 11 and taking the sample into the inside of the sampler 2. A drilling device 21 is attached to the sampler 2. When pressing the sampler 2 into the ground, the drilling device 21 rotates the sampler 2. Once the sampler 2 has been pressed in to a predetermined depth, the sampler 2 is retrieved. This collects the sample taken into the sampler 2. The boreholes created by sample collection are sealed by injecting mortar or grout.

[0027] The water-stopping process S5 is the process of sealing the grout hole 11 after the sampler 2 has been recovered. Since the check valve 12 has been removed, there is a risk of groundwater, soil, etc. flowing in from the grout hole 11. Therefore, in this embodiment, the grout hole 11 is sealed with a water-stopping plug 40. As shown in Figure 9, the water-stopping process S5 includes a plug insertion process S51 and a plug expansion process S52. Figure 14 shows the water-stopping process S5. In the plug insertion step S51, as shown in Figure 14(a), the water-stopping plug 40 is inserted into the grout hole 11. The water-stopping plug 40 is inserted into the grout hole 11 through the prepender 6 and valve 5 while attached to the tip of the rod 7. When the water-stopping plug 40 is inserted into the grout hole 11, the locking portion 45 is locked into the threads of the female screw 13 of the grout hole 11 (see Figure 8). This prevents the water-stopping plug 40 from being pushed back into the interior of the grout hole 11 even if a force is applied to the water-stopping plug 40 from the ground G side. In the plug expansion step S52, as shown in Figure 14(b), the water-sealing member 41 of the water-sealing plug 40 is expanded to seal the grout hole 11 (shield the grout hole 11). The expansion of the water-sealing member 41 is achieved by using the rod 7 to rotate the nut 47, which moves the bolt 46 axially and moves the pressing member 42 toward the retaining member 43. In this way, pressure is applied to the water-sealing member 41 from the front and back, causing the water-sealing member 41 to expand. At this time, the pressing member 42 and the retaining member 43 are prevented from rotating in conjunction with the rotation of the nut 47 by the frictional force between them and the water-sealing member 41.

[0028] The equipment removal process S6 is the process of removing the valve 5, prepender 6, and rod 7 from the grout hole 11. Figure 15 shows the equipment removal process. When the valve 5, prepender 6, and rod 7 are removed from the grout hole 11, the water-stopping plug 40 remains inside the grout hole 11, as shown in Figure 15. Since the grout hole 11 is sealed by the water-stopping plug 40, the inflow of soil, groundwater, etc. from the grout hole 11 is suppressed. The cap restoration process S7 is the process of attaching the cap 14 to the grout hole 11. Figure 16 shows the cap restoration process S7. As shown in Figure 16, the cap 14 is fixed to the grout hole 11 by screwing it into the female thread 13 of the grout hole 11.

[0029] As described above, according to this embodiment, the periphery of the check valve 12 is cut using the check valve removal jig 30, and the cut check valve 12 is taken into the main body 31 and recovered. Therefore, the check valve 12 and any cut pieces of the check valve 12 are not left in the grout hole 11 or in the ground. As a result, in soil investigations using the grout hole 11 after the check valve 12 has been removed, the check valve 12 is prevented from interfering with the investigation. Furthermore, since the check valve 12 is recovered by cutting its periphery with the cutting chip 32, the check valve 12 can be recovered even if it is unable to rotate due to backfill material (grout, etc.) adhering to it.

[0030] The check valve removal jig 30 has a function (check valve holding part 33) to hold the check valve 12, which is taken into the main body 31, so that it does not come out, thus preventing the check valve 12 from being left in the ground. Furthermore, since the check valve holding section 33 is constructed by arranging brushes 33a and 33b with different bristle lengths alternately, it is possible to easily take the check valve 12 into the main body section 31 and hold the check valve 12 in a state where it is difficult for it to come out. In addition, because the check valve holding section 33 is constructed of brushes 33a and 33b with different bristle lengths, it is also possible to collect cutting fragments of various sizes that are generated when cracks or chips occur in the check valve 12 during cutting.

[0031] Furthermore, the cutting tip 32 is a rectangular carbide tip that is tilted relative to the main body 31 and fixed to the main body 31 in a orientation that aligns with the radial axis of the main body 31 when viewed from the front. As a result, the corners of the cutting tip 32 bite into the check valve 12, allowing for efficient cutting of the check valve 12. In addition, because the cutting tip 32 is tilted relative to the inner surface of the main body 31, the cut edges of the check valve 12 are easily guided into the interior of the main body 31. Furthermore, because the cutting tips 32 are arranged at intervals, the check valve 12 is easily guided into the main body 31.

[0032] Furthermore, because the water-stopping plug 40 seals off the grout hole 11 after the soil investigation, groundwater and soil will not flow in from the grout hole 11 even after the valve 5 is removed, making it easy to reinstall the cap 14. The water-stopping plug 40 can ensure high water-stopping performance by having the water-stopping member 41 expand in diameter to closely adhere to the inner circumferential surface of the grout hole 11. Furthermore, since the locking portion 45 is locked into the screw threads (spiral grooves) of the grout hole 11, the water-stopping plug 40 will not be pushed back (come out of the grout hole 11) even under high water pressure. Furthermore, since the moving mechanism 44 is composed of a bolt 46 whose tip is fixed to the pressing member 42 and a nut 47 screwed onto the bolt 46 on the rear surface of the pressing member 43, by rotating the nut 47, the pressing member 42 is pulled closer, applying a pressing force to the water-stopping member 41, and thereby expanding the diameter of the water-stopping member 41.

[0033] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and each of the above-mentioned components can be modified as appropriate without departing from the spirit of the present invention. In the above embodiment, a soil investigation using the grout hole 11 was described, but the use of the check valve removal device 3 in this embodiment is not limited to soil investigation, and may be used, for example, for ground improvement using the grout hole 11. The shape, arrangement, number, and mounting angle of the cutting chips 32 are not limited to those of the above embodiment and may be determined as appropriate. In the above embodiment, the case in which the check valve retaining portion 33 is composed of a plurality of annular brushes arranged in parallel along the axial direction of the main body portion 31 was described. However, the configuration of the check valve retaining portion 33 is not limited, and may be made of, for example, annular rubber material. Also, the length of the bristles of the brushes constituting the check valve retaining portion 33 may be constant. Furthermore, the check valve retaining portion 33 may be composed of spiral brushes. [Explanation of Symbols]

[0034] 1 segment 11 Grout Hall 12 Check valve 2 Samplers 3. Check valve removal device 30 Check valve removal tool 31 Main body 32 cutting inserts 33 Check valve retaining part 34 Connection part 4. Grout hole sealing device 40 Water stop plug 41 Water-stopping member 42 Pressing member 43 Retaining member 44 Moving mechanism 45 Locking part 5 valves 51 Handle 6 Prepender 7 rods 71 Connecting member

Claims

1. A check valve removal tool for removing a check valve installed in a grout hole of a segment, A cylindrical body portion having an outer diameter smaller than the inner diameter of the grout hole, Multiple cutting tips are provided at the tip of the main body, A check valve holding portion is provided on the inner surface of the main body, It comprises a connecting portion formed at the base end of the main body, The main body rotates due to the rotational force applied by the rotational force applying means connected to the connection part. The cutting tip, as the main body rotates, cuts the outer edge portion of the check valve, separating the check valve from the grout hole. The check valve removal jig is characterized in that the check valve holding part holds the check valve, which has been separated from the grout hole and taken into the interior of the main body, so as not to come out of the main body.

2. The check valve removal jig according to claim 1, characterized in that the check valve holding portion has a plurality of annular brushes arranged in parallel along the axial direction of the main body portion.

3. The check valve removal jig according to claim 2, characterized in that the check valve holding portion is made up of brushes with different bristle lengths arranged alternately.

4. The check valve removal jig according to claim 1, characterized in that the cutting tip is rectangular in shape, inclined with respect to the inner surface of the main body when viewed from the side, and fixed to the main body in a direction along the radial axis of the main body when viewed from the front.

5. A valve installed in the grout hole of the segment, A prepender connected to the valve, The rod inserted through the prepender and the valve, A rotational force applying means for applying rotational force to the aforementioned rod, A check valve removal device comprising a check valve removal jig according to any one of claims 1 to 4, attached to the tip of the rod.

6. A method for removing a check valve installed in a grout hole of a segment using a check valve removal jig described in any one of claims 1 to 4, wherein The process of installing the valve and prepender into the grout hole of the segment, The process involves inserting the check valve removal jig attached to the tip of the rod into the grout hole through the prepender and the valve, The process includes rotating the rod and pushing the rod in, A method for removing a check valve, characterized by cutting the outer edge portion of the check valve with a rotating check valve removal jig and incorporating the remaining portion of the check valve into the main body.

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