Installation and removal methods for pipe installation units and pipes.

Abstract

To provide a pipe material installation unit capable of preventing damage to a joint between a pipe material and a penetrating body, and an installation and removal method of a pipe material capable of efficiently removing a pipe material from the ground after the pipe material is used.SOLUTION: A pipe material installation unit 100 comprises a core material 20, a pipe material 50 which is externally mounted to the core material 20, and a penetrating body 60 which is provided at a tip side of them, and installs the pipe material 50 in the ground by driving the core material 20 into the ground. The penetrating body 60 is directly or indirectly provided with a core material attachment / detachment portion 70A to which the tip of the core material 20 is attached and detached. The pipe material 50 is a connection body of a pipe material tip portion 30 including a tip 31 and a general pipe material portion 40. A rigidity of the pipe material tip portion 30 is higher than that of the general pipe material portion 40.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pipe installation unit and a method for installing and removing a pipe.

Background Art

[0002] In the ground, pipes made of vinyl chloride resin pipes (PVC pipes) etc. are installed for various purposes. As an example, pipes as a water collection well for the purpose of water collection, pipes as a casing for injecting chemicals or cement milk etc. into the ground for the purpose of ground improvement, pipes as exploration pipes for the purpose of specifying the formation structure of the ground by exploring the specific resistance according to the porosity etc. can be cited. In any case, since the pipe is inserted into the ground, PVC pipes etc. made of materials that do not affect the ground are often used. In resistivity exploration, since the installation period of the pipe is long and insulation performance is required, PVC pipes are generally used. When installing a pipe such as a PVC pipe into the ground, the tip of the pipe is fitted or screwed onto the side surface of a hard and sharp penetrator (tip cone) to fix it, a core material is installed inside the pipe, and the tip of the core material is fixed or abutted against the back surface of the penetrator, and the core material is driven in (including press-fitting). In some cases, a method is applied to smoothly install the pipe into the ground without affecting the pipe when driving it in. However, in this method, there is a risk of damage at the joint between the penetrator and the pipe made of a relatively low-rigidity pipe such as a PVC pipe compared to the hard penetrator for various reasons.

[0003] For example, when the circumferential frictional force (upward force) between the pipe and the ground is greater than the pushing force (downward force) acting on the core material, tensile fracture may occur at the joint between the penetrator and the pipe in the pipe. On the other hand, when the tip of the penetrator collides with gravel etc. during driving of the core material, the penetration direction of the penetrator deviates sideways to avoid the gravel, and when the penetrator deviates sideways, bending fracture may occur at the joint between the penetrator and the pipe in the pipe.

[0004] Therefore, when installing pipes in the ground by attaching the tip of the pipe to a relatively hard penetrating body and driving in a core material placed inside the pipe, a pipe installation unit is desired that can prevent damage to the joint between the pipe and the penetrating body.

[0005] Furthermore, after the pipe material is installed in the ground, the core material inside the pipe is pulled up to the surface and removed in order to use the pipe material for its intended purpose. For example, in resistivity surveys, a measuring probe is inserted into the pipe material. In water collection wells, a submersible pump or the like is installed inside the pipe material. Furthermore, after the pipes have been used for their intended purpose, it is desirable to remove them by lifting them from the ground to the surface, so that no artificial components are left in the ground. However, to date, there is no established method for installing pipes in the ground in this manner, where the core material used to install the pipes is first brought up to the surface, the pipes are used for their intended purpose, and then the pipes are brought up to the surface and removed from the ground. Therefore, one possible method for removing pipes is to use a casing with a larger diameter than the pipe itself, a method known as "overlay excavation," but this method has drawbacks such as requiring significant drilling time and costs.

[0006] Therefore, a method for installing and removing pipes is desired that involves attaching the tip of the pipe to a relatively hard penetrating body, driving in a core material placed inside the pipe to install the pipe in the ground, pulling up and removing the core material inside the pipe to the surface in order to use the pipe for a predetermined purpose, and then efficiently removing the pipe from the ground without incurring significant time and cost after use.

[0007] Here, Patent Document 1 proposes a pipe driving unit comprising a core material, a pipe material externally mounted on the core material, and a tip member provided at the tip of the pipe material. In this pipe driving unit, the tip member has a core material fixing portion formed therein for attaching and detaching the tip of the core material. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2017-155432 [Overview of the project] [Problems that the invention aims to solve]

[0009] According to the pipe driving unit described in Patent Document 1, the core material that is directly driven into the ground when installing the pipe material is detachably fixed to the tip member, so the core material can be reused and construction costs can be reduced. However, Patent Document 1 does not disclose a means to prevent damage to the joint between the pipe material and the penetration body when installing the pipe material in the ground by attaching the tip of the pipe material to a relatively hard penetration body and driving in a core material that is arranged inside the pipe material. Furthermore, Patent Document 1 does not disclose any means for installing a pipe material in the ground by driving a core material placed inside the pipe material, for using the pipe material for a predetermined purpose, for pulling up and removing the core material inside the pipe material to the surface, or for efficiently removing the pipe material from the ground without incurring time and cost after use.

[0010] The present invention aims to provide a pipe installation unit that can prevent damage to the joint between the pipe and the penetration body when installing a pipe in the ground by attaching the tip of the pipe to a relatively hard penetration body and driving in a core material disposed inside the pipe. Furthermore, the invention aims to provide a method for installing and removing pipes that allows the pipe to be installed in the ground by driving in a core material disposed inside the pipe, and then, in order to use the pipe for a predetermined purpose, the core material inside the pipe to be pulled up to the surface and removed, and after the pipe has been used, the pipe can be efficiently removed from the ground without incurring time and cost. [Means for solving the problem]

[0011] To achieve the above objective, one embodiment of the pipe installation unit according to the present invention is: A pipe installation unit comprising a core material, a pipe material externally mounted on the core material, and a penetrating body provided on the tip side of the core material and the pipe material, wherein the pipe material is installed in the ground by driving the core material into the ground, The penetrating body is provided with a core material attachment / detachment section, either directly or indirectly, into which the tip of the core material is attached and detached. The aforementioned pipe material is a connection between the pipe material tip portion, including the tip, and the general pipe material portion, characterized in that the rigidity of the pipe material tip portion is higher than that of the general pipe material portion.

[0012] According to this embodiment, in a configuration in which a penetrating body is located at the tip of the pipe, the pipe is a connecting body between the pipe tip portion, including the tip, and the general portion of the pipe. Because the rigidity of the pipe tip portion is higher than that of the general portion of the pipe, the rigidity of the joint between the pipe and the penetrating body is increased, thereby effectively suppressing various types of failure, such as tensile failure and bending failure, at the joint of the pipe when it is installed in the ground. In this embodiment, one example is a configuration in which the tip of the pipe material is formed from, for example, a steel pipe, and the general part of the pipe material is formed from, for example, a resin pipe such as a PVC pipe. Furthermore, it is preferable that the penetrating body is made of steel and has a curved shape with a sharp tip or a diameter that decreases towards the tip, and has a shape that has excellent penetration into the ground. In this embodiment, both configurations are included: one in which the penetration body and the pipe are manufactured separately and the tip of the pipe is connected to the penetration body; and another in which the penetration body and the tip of the pipe are manufactured integrally. In the latter configuration, although there is no connection between the penetration body and the pipe, the rigidity of the area near the boundary between the pipe and the penetration body is high, which helps to suppress damage near this boundary.

[0013] Furthermore, the core material can be attached to and detached from the penetration body by directly or indirectly providing a core material attachment / detachment section to which the tip of the core material is attached. Here, "directly or indirectly provided" includes not only the case where the core material attachment / detachment section is directly attached to the penetration body, but also the case where, for example, an axial member is attached to the penetration body, and the core material attachment / detachment section is attached to this axial member, thereby indirectly attaching the core material attachment / detachment section to the penetration body. By attaching an axial member to the penetration body and using this axial member to slide the attachment position of the core material attachment / detachment section toward the ground as desired, it becomes possible to address situations where it would be difficult to attach the core material attachment / detachment section directly to the penetration body due to the internal structure of the pipe. In addition, by sliding the attachment position of the core material attachment / detachment section toward the ground, the ease of attachment when inserting the core material from the ground and attaching it to the core material attachment / detachment section is also improved.

[0014] Furthermore, in another aspect of the pipe installation unit according to the present invention, The penetrating body is further provided with a pipe fixing portion to which the tip of the pipe is fixed.

[0015] According to this embodiment, the penetration body is provided with a pipe fixing portion to which the tip of the pipe is fixed. In other words, the tip of the pipe is connected to the pipe fixing portion of the penetration body, so the penetration body and the tip of the pipe are manufactured as separate parts, resulting in good manufacturability for both. Here, the pipe fixing portion can be in the form of having a screw groove on the surface to which the tip of the pipe is screwed in, or in the form of not having a screw groove on the surface to which the tip of the pipe is fitted, or in the form of the connecting ends being welded together in this fitted state.

[0016] Furthermore, other embodiments of the pipe installation unit according to the present invention are: The length of the tip portion of the pipe is set to be at least twice the length of the pipe fixing portion.

[0017] According to this aspect, the length of the tip of the pipe material is set to be at least twice the length of the pipe material fixing part. Therefore, the connection position between the general part of the pipe material, which has lower rigidity than the tip of the pipe material, and the tip of the pipe material is set at a position more than its length away from the pipe material fixing part. When the tip of the penetrator collides with gravel or the like during the driving of the core material, the penetration direction of the penetrator is displaced sideways so as to avoid the gravel. Even when bending occurs at the joint between the penetrator and the pipe material during the lateral displacement of the penetrator, it is possible to suppress the influence of this bending on the connection position between the general part of the pipe material and the tip of the pipe material, and it is possible to suppress bending failure or the like of the general part of the pipe material with relatively low rigidity.

[0018] Another aspect of the pipe material installation unit according to the present invention is In the connection part between the tip of the pipe material and the general part of the pipe material, a reinforcing member is fixed to both the tip of the pipe material and the general part of the pipe material straddling them.

[0019] According to this aspect, in the connection part between the tip of the pipe material and the general part of the pipe material, since the reinforcing member is fixed to both the tip of the pipe material and the general part of the pipe material straddling them, the connection part can be effectively reinforced by the reinforcing member. Here, a steel pipe or the like can be applied to the reinforcing member, and it can be disposed inside the tip of the pipe material and the general part of the pipe material to serve as a backing steel pipe, and the backing steel pipe can be fixed to the tip of the pipe material and the general part of the pipe material by welding, bolts, screws, or the like.

[0020] Another aspect of the pipe material installation unit according to the present invention is The penetrator includes a reduced-diameter tip, a side surface, and a back surface opposite to the reduced-diameter tip, A first detachable body, which is the core material detachable part, is directly or indirectly attached to the back surface, The core material is detachably connected to the first detachable body.

[0021] According to this embodiment, since the penetrating body has a diameter-reducing tip and a side surface, the side surface acts as, for example, a pipe fixing portion, allowing the pipe tip to be connected to the penetrating body without interfering with the diameter-reducing tip. Furthermore, since the first attachment / detachment body, which is a core material attachment / detachment portion, is directly or indirectly attached to the back surface of the penetrating body, good attachment and detachment of the core material to and from the penetrating body can be achieved.

[0022] Furthermore, other embodiments of the pipe installation unit according to the present invention are: The core material comprises a plurality of segmented core materials, each segmented core material has a screw joint at its end, and the screw joints of two of the segmented core materials that are connected to each other are connected to each other. The first detachable body has a first recess or a first protrusion, and a screw groove is provided on the surface of the first recess or the first protrusion. Of the aforementioned segmented core materials, a second detachable body is attached to the tip of the segmented core material that screws into the first detachable body, and the second detachable body has a second protrusion or second recess into which the first recess or first protrusion fits, and a screw groove is provided on the surface of the second protrusion or second recess. The screw rotation direction of the screw joint and the screw rotation direction of the first and second detachable bodies are set to be opposite.

[0023] In this embodiment, the protrusions or recesses of the second detachable body, which are attached to the ends of multiple segmented core materials constituting the core material, are screwed into the recesses or protrusions of the first detachable body, and each segmented core material is also screwed into each other via a screw joint. By setting the screw rotation direction of the screw joint and the screw rotation direction of the first detachable body and the second detachable body to be opposite, when installing the pipe material in the ground and pulling up and removing the core material, it is possible to prevent the screw joint connecting the segmented core materials from separating when the second detachable body is rotated from the first detachable body to separate them. This makes it possible to form core materials of various lengths by connecting segmented core materials of a predetermined length, while also enabling the separation and removal of the core material from the penetration body after the pipe material has been installed in the ground.

[0024] Furthermore, other embodiments of the pipe installation unit according to the present invention are: In the case where the first detachable body has the first recess and the second detachable body has the second protrusion, The first recess expands in diameter toward the second detachable body side, The second protrusion is characterized by its diameter decreasing toward the first detachable body side.

[0025] According to this embodiment, the recess of the first detachable body expands in diameter toward the second detachable body, and the protrusion of the second detachable body contracts in diameter toward the first detachable body. This improves alignment and connectability when, after using the pipe material in the ground for a predetermined purpose, a core material is inserted into the inside of the pipe material, and the second detachable body at the tip of the core material is rotated to connect it to the first detachable body, which is directly or indirectly attached to the penetration body.

[0026] Furthermore, one embodiment of the method for installing and removing pipes according to the present invention is: A method for installing and removing pipes, comprising installing pipes in the ground, using the pipes in the ground for a predetermined purpose, and then pulling the pipes up to the surface and removing them, A pipe installation unit is prepared, comprising a core material, a pipe material externally mounted on the core material, and a penetrating body provided on the tip side of the core material and the pipe material. The pipe material is then installed in the ground by driving the core material into the ground. The core material removal process involves removing the core material from the penetration body, lifting it up, and removing it. The invention is characterized by having a pipe removal step, in which, after using the pipe material for a predetermined purpose, the core material is returned to the interior of the pipe material and attached to the penetration body, and the pipe material is removed from the ground by pulling up the core material.

[0027] According to this embodiment, by applying the pipe installation unit of the present invention, pipes are installed in the ground by driving a core material, which is placed inside the pipe, and in order to use the pipe for a predetermined purpose, the core material inside the pipe is pulled up to the surface and removed, and after the pipe has been used, the pipe can be efficiently pulled up and removed from the ground without incurring time and cost. [Effects of the Invention]

[0028] According to the pipe installation unit of the present invention, when installing pipes in the ground by attaching the tip of the pipe to a relatively hard penetrating body and driving in a core material disposed inside the pipe, damage to the joint between the pipe and the penetrating body can be prevented. Furthermore, according to the pipe installation and removal method of the present invention, the pipe is installed in the ground by driving in a core material disposed inside the pipe, the core material inside the pipe is pulled up to the surface and removed in order to use the pipe for a predetermined purpose, and after the pipe has been used, the pipe can be efficiently removed from the ground without incurring time and cost. [Brief explanation of the drawing]

[0029] [Figure 1] This is a longitudinal cross-sectional view of an example of a pipe installation unit according to an embodiment. [Figure 2] This diagram illustrates the state in which the second protrusion of the second detachable body is aligned with the first recess of the first detachable body and screwed into place. [Figure 3] This is a longitudinal cross-sectional view of another example of a pipe mounting unit according to the embodiment. [Figure 4] This is a process diagram of an example of a method for installing and removing pipes according to an embodiment. [Figure 5] Following Figure 4, this is a process diagram illustrating an example of a method for installing and removing pipes according to the embodiment. [Figure 6] Following Figure 5, the next diagram shows an example of a pipe installation and removal method according to the embodiment. [Figure 7] Following Figure 6, the next diagram shows an example of a pipe installation and removal method according to the embodiment. [Modes for carrying out the invention]

[0030] The pipe installation unit and the method for installing and removing pipes according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0031] [Pipe installation unit according to the embodiment] First, several examples of the pipe installation unit according to the embodiment will be described with reference to Figures 1 to 3. Here, Figure 1 is a longitudinal cross-sectional view of an example of the pipe installation unit according to the embodiment, and Figure 2 is a diagram illustrating the state in which the second protrusion of the second attachment body is aligned with the first recess of the first attachment body and screwed in. Figure 3 is a longitudinal cross-sectional view of another example of the pipe installation unit according to the embodiment.

[0032] The pipes that make up the pipe installation unit described below are used as exploration pipes for the purpose of identifying the geological structure of the ground by exploring the resistivity corresponding to the porosity. However, the pipes may also be used in other forms, such as as water collection wells for the purpose of collecting water, or as casings for injecting chemical solutions, cement grout, etc. into the ground for the purpose of ground improvement.

[0033] As shown in Figure 1, the pipe installation unit 100 includes a core material 20, a pipe material 50 that is externally mounted on the core material 20, and a penetration body 60 provided on the tip side of the core material 20 and the pipe material 50.

[0034] The penetration body 60 is a steel component and has a conical reduced-diameter tip 61 and a cylindrical body 62 located behind the reduced-diameter tip 61, which are integrally molded. A screw groove is provided on the side surface 63 of the cylindrical body 62, and a third recess 65 extending into the interior of the cylindrical body 62 is provided in the center of the back surface 64 of the cylindrical body 62, and a screw groove is also provided on the inner surface of the third recess 65.

[0035] The tip of the pipe tip 30, which forms the pipe material 50 described below, is screwed into the threaded groove on the side surface 63. Therefore, the side surface 63 forms a pipe fixing portion that secures the pipe material 50 to the penetration body 60. Here, the length of the side surface 63 (height of the cylindrical body 62) is t1.

[0036] A steel first detachable body 70A (an example of a core material detachable part) is attached to the third recess 65 of the penetration body 60, into which the tip of the core material 20, described below, is attached. Specifically, the first detachable body 70A has a cylindrical third protrusion 71 (reduced diameter cylinder) with a screw groove on its surface that screws into the third recess 65, and a larger diameter cylinder 72 that is larger in diameter than the third protrusion 71. The larger diameter cylinder 72 is provided with a first recess 73 with a screw groove on its surface into which a separate second detachable body 70B is screwed.

[0037] When installing the entire pipe installation unit 100 into the ground, the core material 20, which is directly driven in by a driving machine or the like, is formed from a plurality of segmented core materials 10 having a predetermined length. The segmented core materials 10 are made of steel pipes, and each segmented core material 10 has a screw joint (either a male joint 11 or a female joint 12), so that the screw joints 11 and 12 of two segmented core materials 10 that are connected to each other are connected.

[0038] Of the multiple segmented core materials 10, the inner surface of the tip 13 of the segmented core material 10 located on the side of the first detachable body 70A has a screw groove, and a cylindrical fourth protrusion 77, which has a screw groove on its surface and is formed by the second detachable body 70B, is screwed into this screw groove.

[0039] The second detachable body 70B, like the first detachable body 70A, is made of steel and has a fourth protrusion 77, a central cylindrical body 76 integrally formed with the fourth protrusion 77, and a second protrusion 75 integrally formed with the central cylindrical body 76 and having screw grooves on its surface.

[0040] Here, the first recess 73 of the first detachable body 70A expands in diameter toward the second detachable body 70B, and the second protrusion 75 of the second detachable body 70B contracts in diameter toward the first detachable body 70A. Alternatively, the first detachable body may have a protrusion (first protrusion) and the second detachable body may have a recess (second recess), contrary to the illustrated example.

[0041] The pipe material 50 is a connector between a cylindrical pipe material tip portion 30, which includes a tip 31 fixed to the penetration body 60, and a similarly cylindrical pipe material general portion 40. The pipe material tip portion 30 is made of steel pipe, and the tip 31 has a screw groove that screws into the pipe material fixing portion 63 of the penetration body 60.

[0042] On the other hand, an engagement groove is provided at the rear end 32 of the tip portion 30 of the pipe material, so that the tip 43 of the general portion 40 of the pipe material engages with it. The general portion 40 of the pipe material is a hybrid pipe having a plurality of insulating portions 41 of a predetermined length and a conductive portion 42 located between two insulating portions 41.

[0043] The insulating section 41 is formed from a PVC pipe, but it may be made of a synthetic resin pipe of another material that is not electrically conductive and has a certain degree of rigidity. For example, polyethylene pipes are an example of an alternative pipe.

[0044] Thus, the rigidity of the pipe tip 30, which is made of steel pipe, is set higher than that of the general pipe section 40, which is mainly made of PVC pipe. As a result of setting the rigidity of the pipe tip 30 higher than that of the general pipe section 40, the rigidity of the joint between the pipe 50 and the penetration body 60 (the tip 31 and its surrounding area that are joined to the pipe fixing section 63) is increased, which effectively suppresses various types of failure, such as tensile failure and bending failure, at the joint of the pipe 50 when it is installed in the ground. Furthermore, it becomes possible to install the pipe 50 in the ground while preventing these failures, even in hard ground with an N value of about 30.

[0045] Here, tensile failure, as previously described, is a failure that can occur at the joint between the pipe 50 and the penetration body 60 when the circumferential frictional force between the pipe 50 and the ground is greater than the compressive force acting on the core material 20. On the other hand, bending failure is a failure that can occur at the joint between the pipe 50 and the penetration body 60 when the tip of the penetration body 60 collides with gravel or the like during the driving of the core material 20, causing the penetration direction of the penetration body 60 to shift laterally to avoid the gravel.

[0046] Here, the length t2 of the pipe tip portion 30 is set to be at least twice the length t1 of the pipe fixing portion 63. The fact that the length t2 of the pipe tip portion 30 is set to be at least twice the length t1 of the pipe fixing portion 63, in other words, that the connection point between the pipe tip portion 30 and the general pipe portion 40, which has lower rigidity than the pipe tip portion 30, is set to be at a distance of at least t1 of the length of the pipe fixing portion 63 from the end of the pipe fixing portion 63, means that even if bending occurs at the joint between the pipe 50 and the penetration body 60 when the penetration body 60 shifts laterally, the effect of this bending on the connection point between the general pipe portion 40 and the pipe tip portion 30 can be suppressed, and bending failure of the relatively less rigid general pipe portion 40 can be suppressed.

[0047] Furthermore, at the connection between the pipe tip 30 and the general pipe section 40, a reinforcing member 80, formed from a backing steel pipe, is provided on the inside of both sections, straddling both sides, and is fixed to both sides by a plurality of low-head screws 85. Here, the means for fixing the reinforcing member 80 to the pipe tip 30 and the general pipe section 40 may be welding, bolts, or a combination of these, in addition to the low-head screws 85.

[0048] As described above, by setting the length t2 of the pipe tip portion 30 to more than twice the length t1 of the pipe fixing portion 63, bending failure at the connection between the pipe tip portion 30 and the general portion 40 of the pipe is effectively suppressed. Furthermore, since the connection is reinforced by the reinforcing member 80, the connection, which could become a structurally weak point due to being a connection between dissimilar materials, can be effectively reinforced.

[0049] In the pipe installation unit 100, the connection between the penetration body 60 and the first detachable body 70A, the connection between the first detachable body 70A and the second detachable body 70B, the connection between the second detachable body 70B and the divided core material 10, and the connection between the screw joints 11 and 12 of two adjacent divided core materials 10 are all formed by the screwing of the threads on both sides. Here, the screwing rotation direction between the first detachable body 70A and the second detachable body 70B and the screwing rotation direction between the other members are set to be in opposite directions.

[0050] By setting the screw rotation direction in the opposite direction, when installing the pipe material 50 in the ground and pulling up the core material 20 inside it to the surface for removal, it is possible to prevent the screw connection between the first detachable body 70A and the second detachable body 70B from being released simultaneously when attempting to rotate the core material 20 to release the screw connection between the divided core materials 10, as well as other screw connections, from being released simultaneously.

[0051] In other words, by releasing only the screwed-in state of the first detachable body 70A and the second detachable body 70B, the core material 20 (and the second detachable body 70B) can be quickly removed from the penetrating body 60 (and the first detachable body 70A), enabling smooth and reliable removal of the core material 20.

[0052] Furthermore, when removing the pipe 50 from the ground after it has been used for a predetermined purpose, the core material 20 with the second detachable body 70 at its tip is reinserted into the pipe 50, the core material 20 is rotated to screw the second detachable body 70B onto the first detachable body 70A, and then the core material 20 is pulled up, thereby enabling the pipe installation unit 100 to be lifted and removed from the ground.

[0053] In this lifting and removal process, when screwing the second detachable body 70B onto the first detachable body 70A, the first recess 73 of the first detachable body 70A expands in diameter toward the second detachable body 70B, and the second protrusion 75 of the second detachable body 70B contracts in diameter toward the first detachable body 70A. As shown in Figure 2, this makes it easier to align the second protrusion 75 with respect to the first recess 73 in the X1 direction, thus facilitating the operation of positioning the two and enabling efficient screwing of the two.

[0054] In the illustrated example, the connection between each component is made by screwing together threads, but for example, the penetration body 60 and the pipe tip 30 may be made one by welding, and the third recess 65 of the penetration body 60 and the first detachable body 70A may also be made one by welding. Furthermore, the penetration body 60 and the pipe tip 30 may be molded together, the penetration body 60 and the first detachable body 70A may be molded together, or the three components of the penetration body 60, the pipe tip 30 and the first detachable body 70A may be molded together.

[0055] The pipe installation unit 100A in another example shown in Figure 3 differs from the pipe installation unit 100 in that, instead of the first detachable body 70A being directly screwed into the third recess 65 of the penetration body 60, the threaded groove on the surface of the tip 16 of the axial member 15 made of steel pipe is screwed into it, and the third protrusion 71 of the first detachable body 70A is screwed into the threaded groove on the surface of the rear end 17 of the axial member 15.

[0056] For example, a segmented core material can be applied to the axial member 15, and its length t3 is set so that the mounting position of the first detachable body 70A is on the ground side (right side of the page in Figure 3) of the connection between the pipe tip 30 and the general pipe section 40.

[0057] In this way, by connecting the penetrating body 60 and the first detachable body 70A via a shaft-shaped member 15 having a length t3, even when the reinforcing member 80 and the first detachable body 70A interfere with each other and therefore the first detachable body 70A cannot be directly attached to the penetrating body 60, it becomes possible to indirectly attach the first detachable body 70A to the penetrating body 60.

[0058] [Method for installing and removing pipes according to this embodiment] Next, an example of a method for installing and removing pipes according to the embodiment will be described with reference to Figures 4 to 7. Here, Figures 4 to 7 are, in order, process diagrams of an example of a method for installing and removing pipes according to the embodiment.

[0059] In the illustrated example of the pipe installation and removal method, first, as shown in Figure 4, the pipe installation unit 100 is inserted into the ground G to be explored. At this time, the upper end of the core material 20 is made to protrude upward from the pipe material 50, and a cap 92 through which the upper end of the core material 20 passes is placed over the upper end of the pipe material 50. A core material driving machine 90 is then placed on top of the cap 92, and the upper end of the core material 20 is connected to the lower end of the core material driving machine 90.

[0060] The core material 20 is driven downward in the Y1 direction by the core material driving machine 90 through impact, vibration press-in, etc., thereby driving the pipe material installation unit 100 into the ground G in the Y2 direction. This driving installs the pipe material 50 in the ground G and aligns the multiple (three in the illustrated example) conductive parts 42 of the pipe material 50 to the corresponding depth in the ground G (this completes the pipe material installation process).

[0061] Next, as shown in Figure 5, by rotating the core material 20 in the Y5 direction, only the second attachment / detachment body 70B rotates in the Y6 direction, which is the same direction as the first attachment / detachment body 70A, and the screwed state of both is released. At this time, the other members that are screwed together maintain their screwed state because their rotation directions are set opposite to the screwed rotation directions of the first attachment / detachment body 70A and the second attachment / detachment body 70B.

[0062] After releasing the screw connection between the first detachable body 70A and the second detachable body 70B, the core material 20 and the second detachable body 70B are lifted to the ground in the Y7 direction and removed (this completes the core material removal process).

[0063] Next, as shown in Figure 6, multiple electrodes 96 (three in the illustrated example) are attached to the outer circumference of the long measuring sonde 95 at positions corresponding to the spacing between each conductive part 42. The sonde 95 is then inserted into the tube 50 in the Y8 direction, and the measuring sonde 95 is fixed in place with each electrode 96 in contact with the corresponding conductive part 42.

[0064] Subsequently, the measuring sonde 95 is energized, and electricity is passed through the electrodes 96 and conductive parts 42 in the Z1, Z2, and Z3 directions at each depth level of the ground G, respectively. Here, the pipe installation unit 100, as shown in the illustrated example, is installed at multiple locations in the ground G to be explored, and the electricity flowing from each conductive part 42 is passed to the corresponding conductive parts 42 at the depth level of the pipes 50 of the other pipe installation units 100.

[0065] A direct current is applied through the ground G between the conductive parts 42 at corresponding depth levels in multiple pipe installation units 100, and the voltage at that time is measured. By inversely analyzing the measured voltage data, the two-dimensional or three-dimensional resistivity distribution of the ground G can be obtained.

[0066] This is an electrical survey using resistivity tomography that utilizes the property that resistivity (electrical resistance) changes according to the porosity within the ground G to identify the ground properties at each depth level. By installing pipe installation units 100 between boring survey points, which are one-dimensional information, and determining the resistivity distribution, it becomes possible to interpolate the one-dimensional information and effectively grasp the planar geological structure.

[0067] In the illustrated example, a configuration is used in which electrodes 96 specific to the position of each conductive part 42 are attached to the measuring sonde 95. However, it is also possible to use a configuration in which only one electrode 96 is attached to the measuring sonde 95, the measuring sonde 95 is inserted to align the electrode 96 with the conductive part 42 at the measurement depth level, and this is performed for each conductive part 42.

[0068] After the exploration is completed, the measuring sonde 95 is lifted and removed from the pipe 50, as shown in Figure 7. Next, the core material 20 with the second detachable body 70 at its tip is inserted again in the Y9 direction, the core material 20 is rotated in the Y10 direction to screw the second detachable body 70B onto the first detachable body 70A in the Y11 direction, and then the core material 20 is lifted to the ground in the Y12 direction to remove the pipe installation unit 100 from the ground G (this concludes the pipe removal process).

[0069] According to the illustrated method for installing and removing pipes, the pipe 50 is installed in the ground G by driving a core material 20, which is placed inside the pipe 50, into the ground G, and in order to use the pipe 50 for a predetermined purpose, the core material 20 inside the pipe 50 is pulled up to the surface and removed, and after the pipe 50 has been used, the pipe 50 can be efficiently pulled up and removed from the ground G without incurring time and cost.

[0070] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of Symbols]

[0071] 10: Split core material 11: Threaded joint (male joint) 12: Threaded joint (female joint) 13: Tip 15: Shaft-shaped member (divided core material) 16: Tip 17: Rear end 20: Core material 30: Tube tip 31: Tip 32: Rear end 40: Piping general section 41: Insulation 42: Conductive part 43: Tip 50: Tube material 60: Penetrating body 61: Reduced diameter tip 62: Cylinder 63: Side (pipe material fixing part) 64: Back 65: Third recess 70A: 1st removable body (core material removable part) 70B: 2nd detachable body 71: Reduced diameter cylinder (third convex part) 72: Large diameter cylinder 73: First recess 75: Second convex part 76: Central cylinder 77: Fourth protrusion 80: Reinforcement member (backing steel pipe) 85: Low-profile screws 90: Core material driving machine 92: Cap 95: Measuring probe 96: Electrode 100, 100A: Pipe installation unit G: Ground

Claims

1. A pipe installation unit comprising a core material, a pipe material externally mounted on the core material, and a penetrating body provided on the tip side of the core material and the pipe material, wherein the pipe material is installed in the ground by driving the core material into the ground, The penetrating body is provided with a core material attachment / detachment section, either directly or indirectly, into which the tip of the core material is attached and detached. The aforementioned pipe material is a connector between the pipe material tip portion, including the tip, and the general pipe material portion, wherein the rigidity of the pipe material tip portion is higher than that of the general pipe material portion. The aforementioned penetration body is further provided with a pipe fixing portion to which the tip of the pipe material is fixed, The penetrating body comprises a diameter-reduced tip, a side surface, and a back surface opposite to the diameter-reduced tip. The first detachable body, which is the core material attachment / detachment part, is directly or indirectly attached to the back surface. The core material is detachably connected to the first detachable body, The core material comprises a plurality of segmented core materials, each segmented core material has a screw joint at its end, and the screw joints of two interconnected segmented core materials are connected to each other. The first detachable body has a first recess or a first protrusion, and a screw groove is provided on the surface of the first recess or the first protrusion. Of the aforementioned segmented core material, a second detachable body is attached to the tip of the segmented core material that screws into the first detachable body, and the second detachable body has a second protrusion or second recess into which the first recess or first protrusion fits, and a screw groove is provided on the surface of the second protrusion or second recess. A pipe installation unit characterized in that the screw rotation direction of the screw joint and the screw rotation direction of the first and second detachable bodies are set in opposite directions.

2. The pipe installation unit according to claim 1, characterized in that the length of the tip portion of the pipe is set to twice or more the length of the pipe fixing portion.

3. The pipe installation unit according to claim 1 or 2, characterized in that, at the connection between the tip of the pipe and the general part of the pipe, a reinforcing member is fixed to both the tip of the pipe and the general part of the pipe, spanning across both.

4. In the case where the first detachable body has a first recess and the second detachable body has a second protrusion, The first recess expands in diameter toward the second detachable body side, The pipe installation unit according to claim 1 or 2, characterized in that the second protrusion is tapered toward the first detachable body side.

5. A method for installing and removing pipes, comprising installing pipes in the ground, using the pipes in the ground for a predetermined purpose, and then pulling the pipes up to the surface and removing them, A pipe installation step comprising: preparing the pipe installation unit described in claim 1 and installing the pipe in the ground by driving the core material into the ground, The core material removal process involves removing the core material from the penetration body, lifting it up, and removing it. A method for installing and removing pipes, characterized by comprising a pipe removal step, in which, after using the pipes for a predetermined purpose, the core material is returned to the interior of the pipes and attached to the penetration body, and the pipes are removed from the ground by pulling up the core material.

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