JP2006097272A - Method of removing redundant portion of pipe bodies in natural ground reinforcing works - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of removing a redundant portion of pipe bodies in natural ground reinforcing works, according to which the redundant portion of the pipe bodies, protruding from a tunnel cross section into the tunnel is easily cut and removed during construction of the natural ground reinforcing works, in a manner disposing of the same as waste without consuming disposal costs. <P>SOLUTION: The method of removing the redundant portion of the pipe bodies in the natural ground reinforcing works is carried out by using an inner pipe rod 22 on which a drill bit 20 is mounted, and the pipe bodies 24 for housing the internal pipe rod 22 therein. According to the method, prior to excavation of the tunnel cross section, a hole is excavated in front of a cutting face by the drill bit 20, and the pipe bodies 24 are successively spliced to each other and inserted into the hole. Then part of the drill bit 20 and the inner pipe rod are drawn, and a hardener is poured and hardened inside and outside of a circumference of the pipe bodies 24, and thereafter the redundant portion of the pipe bodies, protruding from the tunnel cross section is cut and removed. Herein a terminal pipe which is spliced to a rearmost portion of the pipe bodies 24 and forms the redundant portion is made of a paper pipe or a biodegradable resin pipe. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for removing a surplus portion of a long tubular body placed above a face as a receiving work for reinforcing a natural ground prior to excavation of a tunnel cross section.

  When a tunnel is formed by a natural ground with many cracks, slip surfaces, earth and sand ground, low-strength soft rock, explosive ground, or ground with little soil cover, for example, prior to excavation of the face, Forming a reinforcement called fore-pyring to prevent ground subsidence in the ground by placing a plurality of steel pipes in the upper, approximately 120 ° range, and injecting and hardening a solidifying agent into the ground through each steel pipe An injection-type long steel pipe tip receiving construction is used.

  14 and 15 are explanatory views showing the procedure of a conventional injection-type long steel pipe tip receiving method. In general, in this construction method also called AGF construction method (All Ground Fasten), when excavation is completed, first, as shown in FIG. 14 (A), a sprayed robot layer 2 is used to form a specular spray concrete layer a on the face 1. Next, as shown in FIG. 14 (B), a scaffold by the aerial work vehicle 3 is assembled, and subsequently, marking of a digging hole for placing a steel pipe is performed. Usually, jumbo 4 is used for marking and formation of a digging hole, and a drill bit for drilling a steel pipe 6 or a natural ground to be placed in a guide boom 5 of the jumbo 4 or an inner pipe rod is drilled. Hold the means.

  After the guide boom 5 of the jumbo 4 is positioned at the marking location and the digging hole for placing the steel pipe is formed, the steel pipe 6 is placed in the digging hole as shown in FIG. The casting range of the steel pipe varies depending on the nature of the natural ground, etc., but as described above, it is a predetermined angular range on the upper side of the face surface 1, for example, a range of about 120 °, with a predetermined interval in the circumferential direction. To cast. Further, in the vertical plane, the steel pipe 6 is inclined in a state of being inclined upward at a substantially constant angle within a range of 4 to 6 °, and in the horizontal direction, radially spreads from the center toward the outside. To be placed.

When all the steel pipes 6 have been driven, next, as shown in FIGS. 15A and 15B, the excavation bit and the inner pipe rod are collected from the steel pipe 6, and the injection pipe is inserted instead. 6 is injected with a solidifying agent. The injection tube is connected to the injection pump 7.
Since the solidifying agent diffuses also to the outer periphery of the steel pipe 6 due to the pressure at the time of injection, the reinforcing body is formed in the natural ground as shown in FIG.

Therefore, if a reinforcing body is formed before and after construction for tunnel construction, such as excavation of a face and installation of a supporting structure, a safe and highly reliable tunnel can be formed. If the steel pipe 6 is not widened, that is, if it is a non-widening method , the end side of each steel pipe 6 that has been added last protrudes into the tunnel cross section and interferes with the support work. The part is excised and removed.

Here, in removing the surplus part, conventionally, as shown in JP-A-8-121073, it has a special structure in which the connecting part between the steel pipe of the terminal and the steel pipe in front thereof can be detached. The projecting part, that is, the steel pipe of the terminal that becomes the surplus part is removed, or as shown in Japanese Patent Laid-Open No. 2000-297592, a V-shaped groove that facilitates breakage is formed on the outer peripheral part of the steel pipe. The construction method of removing by breaking and breaking from the groove is used. It is also well known to use a PVC pipe instead of the steel pipe.
JP-A-8-121073 JP 2000-297592 A

  However, in the conventional removal method described above, when cutting and discarding the end side of the pipe body made of a steel pipe or a PVC pipe, the end side of the steel pipe or the PVC pipe is integrated with a solidifying agent. It was difficult to separate the tube from the solidifying agent, and therefore it had to be discarded as a composite waste, which caused a problem that the disposal was expensive.

  The present invention has been made in order to solve the above-described conventional problems, and its purpose is in a natural ground reinforcement work that cuts and removes an excessive portion that becomes a protruding portion of the tubular body with respect to a tunnel cross section. To provide a method for removing a surplus portion of a pipe for reinforcing a natural ground that facilitates excision of the surplus portion and can be disposed of as waste without incurring the cost or can be made unnecessary. It is in.

  In order to achieve the above object, in the method for removing surplus portions of a natural ground reinforcement pipe according to claim 1 of the present invention, an inner tube rod having a drill bit attached thereto, and the inner tube rod A part of the drill bit after inserting the pipe body into the drilling hole in front of the face face drilled by the drill bit prior to excavation of the tunnel cross-section. And extracting the inner tube rod and injecting and solidifying a solidifying agent to the inner and outer peripheries of the tube, and then cutting off and removing the surplus portion that becomes the protruding portion of the tube with respect to the cross section of the tunnel The paper tube is used only for the terminal tube that is added to the rearmost portion of the tube to form the surplus portion, and the steel tube is used for the tube in front of the terminal tube.

  In the method for removing surplus portions of the ground reinforcement pipe according to claim 2 of the present invention, the paper tube is subjected to waterproofing or water repellent treatment.

  In the method for removing surplus portions of the ground reinforcement member according to claim 3 of the present invention, the solidifying agent is injected by inserting a solidifying agent injection tube into the tubular body. Packer forming means is provided for injecting and forming a packer attached to the solidifying agent injection tube to prevent the solidifying agent from entering the surplus portion when the tube is inserted into the tube. In addition, an opening for allowing the packer to enter the borehole outside the tube portion is provided in the tube portion of the packer forming portion, and the packer formation is performed prior to the injection of the solidifying agent. A packer is injected and formed by means, and a barrier is formed inside and outside the tubular body to block out the outflow of the solidifying agent to the surplus portion side.

  In the method for removing the surplus portion of the ground reinforcement pipe according to claim 4 of the present invention, a filler is filled between the outer surface of the paper tube and the digging hole at the entrance of the digging hole. A barrier is provided outside the paper tube to block the supply of the solidifying agent to the surplus portion side.

  In the method for removing the surplus portion of the ground reinforcement pipe according to claim 5 of the present invention, a metal or resin tube that fits into the connecting end portion of the steel tube and the paper tube is connected. A joint is used, and the pipe joint and the steel pipe are connected by screws, and the pipe joint and the paper pipe are connected by an adhesive.

  In the method for removing surplus portions of the ground reinforcement member according to claim 6 of the present invention, a male screw is formed on the outer peripheral surface of the connection end of the steel pipe, and an outer periphery is provided at the front end of the connection end of the paper tube. A metal cylindrical member having a male thread formed on its surface is fastened, and the connecting end of the steel pipe and the cylindrical member are connected by a metal or resin pipe joint that is screwed to these. It is characterized by.

  In the method of removing the surplus portion of the ground reinforcement member according to claim 7 of the present invention, a male screw is formed on the outer peripheral surface of the connection end of the steel pipe, and the outer periphery of the connection end of the paper tube. A metal-coated cylinder formed with a male screw is fastened, and the connection end of the steel pipe and the metal-coated cylinder are connected by a metal or resin pipe joint that is screwed into these. .

  In the method for removing surplus portions of the ground reinforcement pipe according to claim 8 of the present invention, a male screw is formed on the outer peripheral surface of the connection end of the steel pipe, and a resin is formed on the outer periphery of the connection end of the paper tube. The solid pipe is impregnated and solidified to form a male screw, and the connecting ends of the steel pipe and the paper pipe are connected to each other by a metal or resin pipe joint that is screwed into these.

  In the method for removing the surplus portion of the ground reinforcement member according to claim 9 of the present invention, an internal thread is formed on the inner peripheral surface of the connection end of the steel pipe, and the outer periphery is formed at the tip of the connection end of the paper tube. A metal cylindrical member having a male screw formed on its surface is fastened, and the male screw of the cylindrical member is screwed into and connected to the female screw of the steel pipe.

  In the method of removing the surplus portion of the ground reinforcement member according to claim 10 of the present invention, while forming a female screw on the inner peripheral surface of the connection end of the steel pipe, on the outer periphery of the connection end of the paper tube, A metal-coated cylinder in which a male screw is formed is fastened, and the male screw of the metal-coated cylinder is screwed into and connected to the female screw of the steel pipe.

  According to the eleventh aspect of the present invention, there is provided a method for removing surplus portions of a pipe for reinforcing a natural ground, wherein an internal thread is formed on the inner peripheral surface of the connection end of the steel pipe and a resin is formed on the outer periphery of the connection end of the paper tube The solid screw is impregnated and solidified to form a male screw, and the male screw is screwed into and connected to the female screw of the steel pipe.

  According to a twelfth aspect of the present invention, there is provided a method for removing surplus portions of a pipe for reinforcing a natural ground, wherein the paper tube according to the first to eleventh aspects is replaced with a biodegradable resin tube.

  According to the surplus portion removing method of the natural ground reinforcement pipe of the present invention according to the above configuration, the surplus portion is formed of a paper tube or a biodegradable resin tube, so that excision and separation of the solidifying agent are easy, It can be disposed of without using complex waste as in the past. In the case of using a paper tube, preferably, the inner and outer peripheral surfaces are waterproofed or water-repellent to prevent water absorption of the paper tube and prevent the solidifying agent from adhering to the inner surface of the paper tube. Is easier to peel.

  And, when placing the reinforcing body on the ground, either fill the caulking material between the entrance of the digging hole and the solidifying agent injection pipe inserted into the pipe, or on the outer peripheral surface of the solidifying agent injection pipe If the packer capable of forming an expansion is arranged to prevent the solidifying agent from leaking out, the waste of the solidifying agent can be eliminated. For example, when preventing the leakage of the solidifying agent by the packer, the packer is inserted between the injection port and the surplus portion and between the inner surface of the tube body and the outer surface of the injection tube when the injection tube is completely inserted. A packer forming means is attached to the injection pipe so as to be arranged, and an opening for allowing the packer to enter into the digging hole on the outer periphery of the pipe is formed at the packer forming portion of the paper pipe. Keep it. If an injection tube is inserted and foaming material such as urethane is supplied to the packer formation site by the packer forming means, the packer forms a barrier against the inner surface of the paper tube and the inner surface of the digging hole, so that it solidifies to the surplus part side The entry of the agent is prevented, and the surplus part remains hollow. For this reason, since excision is easy and it is not necessary to peel off the solidifying agent from the surplus part, the cost for excision and disposal is reduced.

  As is apparent from the above description, according to the present invention, in the method for reinforcing a natural mountain in which a surplus portion that is a protruding portion of a tubular body is excised from the tunnel cross section and removed, the surplus portion is easily excised. At the same time, the cost for disposal can be reduced.

  Hereinafter, preferred embodiments of the present invention applied to a long steel pipe tip receiving method will be described in detail with reference to the accompanying drawings.

  FIGS. 1-10 shows one Example of the surplus part removal method of the pipe for ground reinforcement according to this invention, FIG. 1 is FIG. 14 in the long steel pipe tip receiving method of the prior art example mentioned above. This corresponds to the steel pipe placing step (C).

  In the method of removing the surplus portion of the ground reinforcement member according to the present embodiment, an inner tube rod 22 having a drill bit 20 for forming a digging hole in the face is attached to the tip, and the inner tube rod 22 is disposed inside. And an outer pipe 24 made of steel pipe that is left in the ground.

  An extension rod 26 is screwed and connected to the rear end portion of the drill bit 20, and an inner tube rod 22 is screwed and connected to the rear end side of the extension rod 26 via a wing coupling 28. The inner tube rod 22 is inserted through the axial center of the wing coupling 28, and the outer peripheral edge is in sliding contact with the inner circumferential surface of the outer tube 24 to position the inner tube rod 22 on the central axis of the outer tube 24.

  As shown in the exploded explanatory view of FIG. 2, the inner tube rod 22 is a tubular rod with screws engraved at both ends, which are sequentially screwed through the relay coupling 30 as the excavation progresses. Connected. When the inner tube rod 22 is connected, the inside of the inner tube rod 22 becomes a medium supply passage 32 for supplying a cooling medium A such as drill water or air to the drill bit 20. Although not shown in detail, the medium supply passage 32 opens at the tip of the drill bit 20. The outer tube 24 includes a leading tube 24a, a plurality of intermediate tubes 24b, a terminal tube 24c, a short head tube 24f, and a discharger head tube 24g.

  The front tube 24a and the intermediate tube 24b are hollow cylindrical tubular bodies in which a male screw portion 240 is engraved on one end and a female screw portion 241 on the other end, and a large number of through holes 242 are formed on the outer peripheral surface. Is used. As the excavation proceeds, a plurality of intermediate tubes 24b are sequentially screwed to the intermediate tube 24b that is screwed to the rear end of the leading tube 24a.

  Incidentally, a paper tube is used for the terminal tube 24c. The paper tube used for the terminal tube 24c is waterproofed or volatilized to prevent water absorption. As the excavation progresses, the terminal pipe 24c is connected to the rear end of the rearmost intermediate pipe 24b via a pipe joint described later, and the short head pipe 24f is screwed to the front end of the front pipe 24a. The discharger head tube 24g is screwed to the rear end of the terminal tube 24c.

  The outer pipe 24 configured in this manner is a discharge passage 34 for the drilling slime B generated during excavation between the outer peripheral surface of the inner pipe rod 22 inserted therein. Further, as shown in FIG. 3, a cylindrical casing shoe 36 having both ends opened is screwed to the short head tube 24f at the distal end side of the outer tube 24. The discharger head tube 24g is provided with a plurality of discharge holes 24j along the circumferential direction. A drifter 42 that transmits thrust, rotation, and impact to the drilling rod 20 is coupled to the rear end side of the inner tube rod 22 via a sleeve 44.

  4 to 7 are sectional views showing various connection structures between the terminal tube 24c and the rearmost intermediate tube 24b. FIG. 4 shows the first connection structure and FIG. 5 shows the second connection structure. 6 shows a third connection structure, and FIG. 7 shows a fourth connection structure. In addition, in the 1st connection structure of FIG. 4, although it has shown in the state laid in the natural ground, in FIG. 5-7, only the connection part is shown.

  In the connection structure shown in FIG. 4, the terminal pipe 24 c is connected to the rearmost intermediate pipe 24 b via the pipe joint 60. That is, a male screw 24b1 having a stepped diameter is provided on the outer peripheral surface of the rear end, which is the connection end of the intermediate pipe 24b with the terminal pipe 24c, and the intermediate thread is formed on the inner peripheral surface of one end of the pipe joint 60. A female screw 60a that is screwed into the male screw 24b1 of the tube 24b is formed, and a fitting portion 60b that fits the tip of the terminal tube 24c is formed on the inner peripheral surface of the other end portion, and the intermediate tube 24b is formed on the female screw 60a of the pipe joint 60. Then, the front end portion of the terminal tube 24c is inserted into the cylindrical fitting portion 60b at the rear end portion of the pipe joint 60, and the joint surfaces thereof are joined with an adhesive. It is what I did. In this case, since the terminal tube 24c is a paper tube, it is difficult for shear failure to occur in the adhesive, so that the connection strength and reliability are improved. Further, since the pipe joint 60 serves as a reinforcing material for the terminal pipe 24c, the strength of the terminal pipe 24c is also increased. Further, the outer diameter of the pipe joint 60 is made to be flush with the outer diameter of the intermediate pipe 24b so as not to become a resistance at the time of fitting into the natural ground.

  In the second connection structure shown in FIG. 5, a metal cylindrical member 61 is fitted and secured to the tip of the paper tube of the terminal tube 24c, and this metal cylindrical member 61 is attached to the intermediate tube 24b. They are connected via a pipe joint 62. A through hole for inserting a male screw 61a for connecting the end pipe 24c to the pipe joint 62 and a rivet 61c for fixing the paper pipe of the end pipe 24c on the outer peripheral surface of the metal cylindrical member 61. A hole 61b is formed, and a through hole 24c2 for inserting the rivet 61c is formed in the outer periphery of the end of the paper tube of the terminal tube 24c corresponding to the through hole 61b.

  Insert the paper tube tip of the terminal tube 24c into the metal cylindrical member 61, and insert the rivet 61c into the through hole 61b of the metal cylindrical member 61 and the through hole 24c2 formed in the paper tube of the terminal tube 24c. When the caulking process is performed, the metal cylindrical member 61 is integrated with the paper tube tip of the terminal tube 24 c, and the paper tube tip of the terminal tube 24 c is reinforced by the metal cylindrical member 61. Next, the male screw 24b1 at the rear end of the intermediate pipe 24b is screwed into the female screw 62a on the inner peripheral surface of one end of the pipe joint 62, and the male screw 61d on the outer peripheral surface of the metal cylindrical member 61 is further connected to the pipe joint 62. When the other end portion of the inner peripheral surface is screwed into the female screw 62b, the connection between the intermediate tube 24b and the terminal tube 24c is completed.

  In this way, the connection side end of the terminal tube 24c is reinforced by the metal cylindrical member 61, and the paper tube of the terminal tube 24c is connected to the intermediate tube 24c via the metal cylindrical member 61 and the pipe joint 62. Therefore, the strength and reliability related to the connection are improved.

  In this connection method, the rivet 61c is used as an example of a fastening element. However, a set screw or the like may be used instead of the rivet 61c, and a caulking process may be performed on the tip of the screw.

  In the third connection structure shown in FIG. 6, the end portion of the terminal tube 24c is reinforced with a metal-coated tube 63, and the metal-coated tube 63 is connected to the intermediate tube 24b via a pipe joint 62. The metal-coated cylinder 63 is connected to one side of an end surface covering portion 63a that covers the end surface portion of the distal end portion of the terminal tube 24c, and an inner peripheral surface covering portion 63b that covers the inner peripheral surface of the terminal tube 24c, and to the other side. The outer periphery covering portion 63c that covers the outer peripheral surface of the terminal tube 24c is connected, and the outer surface covering portion 63c is formed with a claw 63d that bites into the outer peripheral surface of the terminal tube 24c by embossing or the like.

  When the metal-coated cylinder 63 is attached, the outer surface covering portion 63c is opened outward with respect to the end surface covering portion 63a. Next, the fitting portion 63e of the metal coated cylinder 63 formed in a substantially U shape by the outer surface covering portion 63c, the inner surface covering portion 63b, and the end surface covering portion 63a is fitted into the distal end portion of the terminal tube 24c. Next, when the claw 63d is bitten into the outer peripheral portion of the terminal tube 24c by bending the outer surface covering portion 63c inward with the end surface covering portion 63a in contact with the end surface of the terminal tube 24c, the distal end portion of the terminal tube 24c The metal-coated cylinder 63 is integrated with each other.

  Next, the female screw 62a on the inner peripheral surface of one end of the pipe joint 62 is screwed into the male screw 24b1 on the outer peripheral surface of the intermediate pipe 24b, and the metal coated cylinder is inserted into the female screw 62b on the inner peripheral surface of the other end of the pipe joint 62. The male screw 63f on the outer peripheral surface 63 is screwed in to complete the connection of the terminal tube 24c to the intermediate tube 24b.

  According to the third connection structure, since the section modulus of the metal-coated cylinder 63 is higher than the section modulus of the metal cylindrical member 61 at the joint portion with the paper tube, the strength and reliability of the connection are The height is higher than that of the metal cylindrical member 61 having the second connection structure shown in FIG. In this third connection structure, even if it is finally fixed with a rivet (not shown) in order to eliminate the outer opening of the outer peripheral surface covering portion 63c and the inner peripheral surface covering portion 63b of the metal-coated tube 63. Good. Further, when the strength is increased by increasing the thickness of the metallic covering cylinder 63, the inner covering portion 63b and the end surface covering portion 63a may be eliminated.

  The fourth connection structure shown in FIG. 7 reinforces the distal end portion of the terminal tube 24c by resinating the distal end portion of the end tube 24c, and connects to the male screw 24c1 formed at the distal end portion via a pipe joint 62. It is what I did. The distal end portion of the terminal tube 24c is made resin by impregnating at least the outer periphery of the distal end portion with molding, and then the male screw 24c1 is formed simultaneously with molding or by engraving thereafter. When the male screw 24c1 at the tip of the terminal tube 24c is screwed into the female screw 24b2 at the inner peripheral surface of the rear end of the intermediate tube 24b and the first terminal tube 24 is connected to the pipe joint 62, the connection to the intermediate tube 24b is completed. .

  In addition, not only the front-end | tip part of the terminal pipe 24c but the whole terminal pipe 24c may be impregnated, and the whole intensity | strength may be improved. Further, the terminal tube 24c may be formed of a resin in which cellulose (including short fibers and long fibers) and a resin are mixed, and further, a biodegradable resin containing cellulose or a biodegradable resin containing no cellulose. The terminal tube 24c may be made of a degradable resin.

  Here, the biodegradable resin is, for example, heat generated by using, for example, polylactic acid extracted from a plant such as corn as a raw material, and using a special surfactant for this, and fine particles of clay. It is a resin that is resistant to water, and the starch component accounts for 60 to 80% as a main component.

  When such a biodegradable resin is used, microorganisms in the soil degrade the biodegradable resin. Therefore, when the excess portion of the terminal tube 24c is excised and discarded as described later, it is treated in a specific environment. It is not necessary to dispose of it and it can be disposed of together with the excavation sludge, so the disposal cost is greatly reduced.

  Referring to FIG. 3 showing an enlarged view of the periphery of the hole drilling head 20, the hole drilling head 20 is composed of a ring lost bit 20a and an inner bit 20b, and an inner member fitted to the ring lost bit 20a. A bit 20 b is inserted into the casing shoe 36. A concave groove 20c divided along the axial direction is provided on the outer peripheral surface of the inner bit 20b. The front end side of the concave groove 20c opens at the front end edge of the inner bit 20b, and the rear end side is The slime B communicates with the discharge passage 34. Between the inner bit 20b and the casing shoe 36, a thrust and impact power transmission portion 46 applied from the drifter 42 is provided. The power transmission portion 46 of the present embodiment includes a step portion 48 provided on the inner peripheral surface of the casing shoe 36 and a convex portion 50 that abuts on the step portion 48. The convex portion 50 is an inner bit. It is provided on the outer peripheral surface of 20 b and is disposed on the distal end side of the outer tube 24. Note that the contact relationship between the stepped portion 48 and the convex portion 50 does not extend over the entire circumference of the stepped portion 48, but is divided at the concave groove 20c provided on the outer periphery of the inner bit 20b.

  When installing the outer tube 24 on a natural ground, the drifter 42 is driven as shown in FIG. Thrust, rotation, and impact are transmitted from the drifter 42 to the drill bit 20 via the inner tube rod 22, thereby excavating the natural ground D and forming the drill hole C as shown in FIG. At this time, cooling medium A such as drilling water, air, and bubbles is supplied from the medium supply passage 32 to the drill bit 20, and the slime B excavated by the drill bit 20 is discharged to the outside through the discharge passage 34. Is done.

  On the other hand, the thrust and impact of the drifter 42 are transmitted to the outer tube 24 via the power transmission portion 46 provided on the distal end side of the outer tube 24, thereby the outer tube 24 is ground. Since it is inserted into the drilling hole C formed by the hole bit 20 by the front pulling method, even if the terminal tube 24c is a paper tube or a biodegradable resin tube, the tube will not be damaged during placement. In this way, when the thrust and impact power transmission portion 46 is provided on the distal end side of the outer tube 24 and the outer tube 24 is inserted into the drilling hole C by the forward pulling method, the slime discharge passage is formed on the rear end side of the outer tube 24. There is no need to provide a placing jig for closing 34. Thereby, it can be set as the discharge port of the drilling slime B which opened the rear end side of the outer pipe 24, and by discharging the rear end of the outer pipe 24, the drilling slime B can be discharged smoothly without accumulating inside. be able to. Although not shown in detail, the outer tube 24 is positioned and supported concentrically with the inner tube rod 22 by a centerer installed at an appropriate place.

  When the outer tube 24 having a predetermined length is driven into the natural ground D, the inner bit 20b and the inner tube rod 22 of the drill bit 20 are recovered in the same manner as in FIG. 12, and instead, as shown in FIG. Further, the solidifying agent injection tube 66 attached with the packer forming means P attached thereto by lashing or the like is inserted. In this case, as the solidifying agent injection pipe 66, a tube having a length that allows the injection port 66a at the tip to exist forward of the excavation direction with respect to the surplus portion of the terminal pipe 24c in a state where the insertion into the outer pipe 24 is completed, The means P is arranged between the tip of the surplus portion of the terminal tube 24c and the inlet 66a. Here, in the illustrated example, the packer P0 is formed at the rear end portion of the intermediate tube 24b in the vicinity of the connecting portion of the terminal tube 24c. An opening 67 is formed to guide the packer forming material into the borehole in the outer periphery of the tube.

  The packer forming means P includes a forming material supply pipe P1 that supplies foamed urethane or the like as a packer forming material, and a bag body P2 that can be expanded and contracted to define a packer forming space in a predetermined portion inside the intermediate pipe 24b. The bag body P2 is positioned in front of and behind the opening 67 and is provided with a pair, and the bag body P2 is supplied with air for inflating it and bringing it into close contact with the inner peripheral surface of the intermediate tube 24b. An air supply pipe P3 is connected, and the tip of the forming material supply pipe P1 extends to a packer forming space sandwiched between both bag bodies P2.

  That is, air is supplied into the bag body P2 to inflate, and the front and back of the opening 67 are closed with the bag body P2, thereby defining a packer forming space. Then, when a packer forming material such as urethane foam is supplied and filled into the packer defining space from the forming material supply pipe P1, the packer forming material leaks out from the opening 67 of the intermediate pipe 24b to the outer peripheral portion, and the intermediate pipe 24b. The packer P0 that is in close contact with these is formed at the inner and outer packer forming sites of the pit and the pit, and the barriers W1 and W2 are formed for the packer P0 to prevent the solidifying agent from entering the terminal tube 24c. become.

  For this reason, even if the solidifying agent is injected into the outer tube 24 from the solidifying agent injection pipe 66 thereafter, the barriers W1 and W2 prevent the solidifying agent from entering the surplus portion of the terminal tube 24c. The solidifying agent injected into the outer pipe 24 through the solidifying agent injection pipe 66 is filled and supplied from the through hole 242 of the intermediate pipe 24b and the opening of the leading end of the leading pipe 24a into the ground hole, and then solidified and ground. Reinforcing body to prevent settlement.

  FIG. 9 is an explanatory view showing a tunnel cross section after the reinforcement body is installed. The member shown by H shape in the figure is the arch-type support 501 installed along the tunnel cross section to be excavated. This support 501 is installed immediately before the current face 521 before the outer tube 24 is driven.

  The outer pipe 24 made of steel pipe placed in the present embodiment is placed in the natural ground D at a predetermined inclination angle from the lower side to the upper side of the support 501. The outer tube 24 is provided with the terminal tube 24c so that the rear end side slightly protrudes from the face 521. Before excavating from the current face 521 toward the front side, the end part of the terminal pipe 24c protruding from the face 521 is subjected to vibration and impact by a breaker or the like to break off the excess part. Thereafter, by excavating, the face 521 before excavation is advanced to the face 522 after excavation, the supporting work 502 is installed, and then the surplus portion of the terminal pipe 24c is broken and removed in the same manner. Further, the face 522 is advanced to the face 523 by excavation to install the support work 503, and then the excess portion of the terminal pipe 24c is removed by breakage. After this process, the outer tube 24 does not become an obstacle to the installation of the support 505 and is not removed.

  As described above, in the present invention, the end pipe 24c is formed of a paper pipe or a biodegradable resin pipe, and the barriers W1, W2 are formed by the packer P0 to enter the solidifying agent into the surplus portion side. This prevents the wasteful consumption of the solidifying agent and makes it easy to break. Since the broken excess part is hollow and not filled with the solidifying agent, it can be disposed as a single general waste, and the disposal cost is reduced.

  FIG. 10 shows a case where the amount of the solidifying agent used is reduced by filling the entrance of the pit with a caulking material. That is, after the solidifying agent injection pipe 66 is inserted into the outer pipe 24 from the intermediate pipe 24b, the terminal pipe 24c, etc., a barrier wall W3 is formed to prevent leakage of the solidifying agent by filling the caulking material at the entrance of the digging hole. To do. When the entrance of the digging hole is closed by the barrier W3, the solidifying agent does not leak to the outside even if the solidifying agent is injected by the injection pipe 66, and from the opening of the digging bit and the through hole 242 of the intermediate pipe 24b. Since the solidifying agent is supplied to the natural mountain side, the reinforcing body can be formed without waste. In this case, since the packer P0 is not provided as described above, the terminal tube 24c is also filled with the solidifying agent. However, the paper tube or the biodegradable resin tube can be easily peeled off or removed from the solidifying agent. Since the excess part can be separated from the solidifying agent and discarded, the disposal cost can be reduced even when a caulking material is used.

  FIGS. 11-13 show the modification of the connection structure of the intermediate pipe 24b and the terminal pipe 24c. In these modified examples, as shown in the figure, an internal thread 24b2 is formed on the inner peripheral surface of the connecting end of the steel pipe, which is the intermediate pipe 24b, and a terminal pipe 24c made of a paper tube is connected to the internal thread 24b2. Male thread portions 61d, 63f, 24c1 formed on the outer peripheral surface of the end are screwed together so that both are directly connected without using a pipe joint. Here, the configuration of the male screw portions 61d, 63f, 24c1 of the paper tube which is the terminal tube 24c is exactly the same as the case of FIG. 5 to FIG. 7 described above. 11 is a modification of FIG. 5, FIG. 12 is a modification of FIG. 6, and FIG. 13 is a modification of FIG.

  In addition, although description of each embodiment mentioned above demonstrated the case where this invention was applied to a long steel pipe tip receiving construction, this invention is not limited to this, A natural mountain is reinforced using a steel pipe. After that, it can be applied when it is necessary to remove the steel pipe. Further, instead of the steel pipe, a fiber reinforced resin pipe or the like may be adopted for the other pipe body 24 excluding the terminal pipe 24c, that is, the tip pipe 24a and the intermediate pipe 24b.

It is construction explanatory drawing at the time of driving in the steel pipe for demonstrating the surplus part removal method of the pipe body for ground reinforcement according to this invention. It is a principal part exploded view of FIG. It is a principal part enlarged view of FIG. It is explanatory drawing which shows the 1st connection structure of an intermediate pipe and a terminal pipe. It is explanatory drawing which similarly shows the 2nd connection structure of an intermediate pipe and a terminal pipe. It is explanatory drawing which similarly shows the 3rd connection structure of an intermediate pipe and a terminal pipe. It is explanatory drawing which similarly shows the 4th connection structure of an intermediate pipe and a terminal pipe. It is explanatory drawing which shows the state which installed the packer formation means. It is explanatory drawing which shows the tunnel cross section after reinforcement body installation. It is explanatory drawing which shows the state which installed the barrier with the caulking material. It is explanatory drawing which shows the modification of the 2nd connection structure of the intermediate | middle pipe | tube and terminal pipe | tube shown in FIG. It is explanatory drawing which shows the modification of the 3rd connection structure of the intermediate | middle pipe | tube and terminal pipe | tube shown in FIG. It is explanatory drawing which shows the modification of the 4th connection structure of the intermediate | middle pipe | tube and terminal pipe | tube shown in FIG. It is explanatory drawing which shows the procedure of the conventional injection type long steel pipe tip receiving method. It is explanatory drawing which shows the procedure of the conventional injection type long steel pipe tip receiving construction method following the procedure of explanatory drawing of FIG.

Explanation of symbols

20 Drilling bit 22 Inner tube rod 24 Outer tube 24a Leader tube 24b Intermediate tube 24c Terminal tube A Cooling medium B Drilling slime C Drilling hole D Ground P Packer forming means P0 Packer P1 Forming material supply tube P2 Bag body P3 Air supply tube

Claims (12)

  Using an inner tube rod fitted with a drill bit and a pipe body that accommodates the inner tube rod, the pipe is inserted into the drill hole in front of the face face excavated by the drill bit prior to excavation of the tunnel cross section. After inserting the body while sequentially adding it, a part of the drill bit and the inner tube rod are extracted, and a solidifying agent is injected and solidified on the inner and outer circumferences of the tube, and then the tunnel cross-section is When excising and removing the surplus portion that becomes the protruding portion of the tubular body, a paper tube is used only for the terminal tube that is added to the rearmost portion of the tubular body to form the surplus portion, and the tubular body in front of the terminal tube A method for removing surplus portions of a pipe for reinforcing natural ground characterized by using a steel pipe.   The method for removing surplus portions of a pipe for reinforcing natural ground according to claim 1, wherein the paper tube is waterproofed or water-repellent.   The solidifying agent is injected by inserting a solidifying agent injection tube into the tubular body. When the solidifying agent injection tube is inserted into the tubular body, the solidifying agent injection tube is attached to the excess portion side. Provided with a packer forming means for injecting and forming a packer for preventing the entrance of the solidifying agent in front of the surplus portion, and the packer into the borehole outside the tube portion at the tube portion of the packer forming portion Before the injection of the solidifying agent, the packer is injected and formed by the packer forming means, so that the solidifying agent flows into and out of the tubular body. 3. A method for removing surplus portions of a pipe for reinforcing natural ground according to claim 1, wherein a barrier is provided to block the ground.   At the entrance of the digging hole, a barrier is formed between the outer surface of the paper tube and the digging hole so as to block the supply of the solidifying agent to the surplus portion side outside the paper tube. The surplus part removal method of the pipe body for natural ground reinforcement works of Claim 1 characterized by the above-mentioned.   For the connection between the steel pipe and the paper pipe, a metal or resin pipe joint fitted to these connection ends is used, and the pipe joint and the paper pipe are bonded together by screws. The surplus part removal method of the pipe for a natural ground reinforcement work according to any one of claims 1 to 4, wherein the pipe is connected by an agent.   Forming a male screw on the outer peripheral surface of the connecting end of the steel pipe, and fastening a metal cylindrical member having an outer thread formed on the outer peripheral surface at the tip of the connecting end of the paper tube; and a connecting end of the steel pipe; The surplus part of the pipe body for ground reinforcement according to any one of claims 1 to 4, wherein the cylindrical member is connected by a metal or resin pipe joint that is screwed to the cylindrical member. Removal method.   A male screw is formed on the outer peripheral surface of the connecting end of the steel pipe, and a metal-coated tube formed with a male screw is fixed to the outer periphery of the connecting end of the paper tube, and the connecting end of the steel pipe and the metal-coated tube The surplus part removal method of the pipe body for natural ground reinforcement works in any one of Claims 1-4 which was made to connect with these by the metal or resin pipe joint screwed together.   A male screw is formed on the outer peripheral surface of the connection end of the steel pipe, and a male screw is formed by impregnating and solidifying resin on the outer periphery of the connection end of the paper pipe, and the connection ends of the steel pipe and the paper pipe are screwed together. The surplus part removal method of the pipe for a natural ground reinforcement work according to any one of claims 1 to 4, wherein the pipes are connected by a metal or resin pipe joint.   A steel cylindrical member having a male screw formed on the outer peripheral surface thereof is fixed to the distal end of the connecting end of the paper tube, and a male cylindrical screw is formed on the inner peripheral surface of the connecting end of the steel tube. 5. The method for removing surplus portions of a natural steel reinforcement pipe according to any one of claims 1 to 4, wherein the steel pipe is screwed into and connected to an internal thread.   A female thread is formed on the inner peripheral surface of the connection end of the steel pipe, and a metal-coated cylinder with a male screw is fixed to the outer periphery of the connection end of the paper pipe. The male screw of the metal-coated cylinder is attached to the steel pipe. The excess part removing method of the pipe for a natural ground reinforcement work according to any one of claims 1 to 4, wherein the pipe is connected to a female screw.   A female screw is formed on the inner peripheral surface of the connection end of the steel pipe, and a male screw is formed by impregnating and solidifying resin on the outer periphery of the connection end of the paper tube, and the male screw is screwed to the female screw of the steel pipe to be connected. The surplus part removal method of the pipe for natural ground reinforcement works in any one of Claims 1-4 characterized by the above-mentioned. The method for removing surplus portions of a pipe for reinforcing natural ground according to any one of claims 1 to 11, wherein the paper tube is replaced with a biodegradable resin tube.

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