JP4318601B2 - Steel pipe for ground reinforcement - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a natural steel reinforcing driven steel pipe that is driven into a natural ground where a loose ground or the like exists to stabilize the natural ground.

  In tunnel construction, if the natural ground is soft, it is necessary to excavate the tunnel while stabilizing the natural ground. Therefore, every time a certain length of tunnel is excavated, A plurality of steel pipes fitted with perforated bits are driven radially in the circumferential direction of the tunnel, and through these steel pipes, curable materials such as cement milk or urethane resin liquid are injected and hardened, and in this state the steel pipes are cured. Stabilization of the ground is carried out by leaving the ground in the ground.

As such a ground-stabilized steel pipe, for example, as described in Patent Document 1, a slime feed groove and an air jet communicated from the front surface to a perforated bit attached to the tip of the steel pipe. An inner pipe is provided in the steel pipe via a down-the-hole hammer connected to the drill bit, and the drill bit is driven by the down-the-hole hammer while air is ejected from the air outlet of the drill bit through the inner pipe. There is known a structure in which a natural ground is excavated, and slime as excavated material is taken into the steel pipe through the slime feed groove and discharged from the rear end side.
JP-A-8-338191

  According to the ground-stabilized driven steel pipe configured as described above, the excavated material excavated by the drill bit is taken into the steel pipe through the slime feed groove provided in the drill bit. The gap between the holes is less likely to clog the gap, and therefore, there is an advantage that the possibility that the advancement of the steel pipe is restricted by the excavated material and cannot be advanced is reduced. The down-the-hole hammer that strikes and drives the drill bit provided in the tip is a member having rigidity and a large cross-sectional area. Therefore, the slime is formed by a gap between the outer peripheral surface and the inner peripheral surface of the steel pipe. There is a possibility that the discharge passage becomes extremely narrow and smooth discharge cannot be performed.

  In particular, when the ground where the steel pipe is to be driven is a fragile rocky ground, the excavated material is cracked so that the gap between the inner peripheral surface of the steel pipe and the outer peripheral surface of the down-the-hole hammer has the large diameter. As a result, there is a problem that the excavated material is obstructed, and the excavated material cannot be removed and the steel pipe cannot be driven. Therefore, the size of the cross-sectional area of the slime feed groove provided in the perforated bit must be formed in a small-diameter slime feed groove corresponding to the gap, and not only the soil removal efficiency is deteriorated, There arises a situation in which the excavated material goes around between the outer peripheral surface of the steel pipe and the excavation hole and it becomes difficult to drive the steel pipe.

  The present invention has been made in view of such problems, and the object of the present invention is to enable driving into the natural ground while discharging the excavated material efficiently and to perform driving smoothly and reliably. An object of the present invention is to provide a steel pipe for ground reinforcement.

  In order to achieve the above-described object, a ground steel reinforcing driven steel pipe according to the present invention includes, as described in claim 1, a steel pipe configured to connect a rear end portion to a hammering / rotation transmission member, The drill bit is integrally fixed to the front end, and a water supply pipe disposed at the center of the steel pipe over substantially the entire length of the steel pipe. The drill bit includes a water injection hole penetrating between the front and rear surfaces. The drilling material intake hole is provided, the front end of the water supply pipe is connected to and communicated with the rear end of the water injection hole, and the drilling material intake hole is formed between the inner peripheral surface of the steel pipe and the outer peripheral surface of the water supply pipe. It is made into the structure connected with the excavation discharge path formed of the part.

Further, in the ground-steel reinforcing driven steel pipe configured as described above, the rear end of the water supply pipe can be moved back and forth to the front end of the water supply small-diameter connecting pipe disposed in the center of the hammering / rotation transmission member. And it was comprised so that it could rotate freely.

According to a second aspect of the present invention, there is provided a steel pipe for reinforcing a natural ground, wherein a front side steel pipe having a drill bit fixed to a front end, a rear side steel pipe having a rear end connected to an impact / rotation transmission member, and It is characterized by comprising a plurality of steel pipes with an additional steel pipe part interposed and connected between the first steel pipe and the last steel pipe.

Furthermore, in the invention according to claim 2, in the ground pile reinforcing driven steel pipe composed of a plurality of steel pipe portions as described above, the length of each steel pipe is set in the center portion of the leading steel pipe , the additional steel pipe, and the last steel pipe. The water pipes having substantially the same length are supported on the inner peripheral surface of the steel pipe by the support brackets, respectively, and the opposite ends of the water pipes in the adjacent steel pipes are slidable back and forth and rotatably connected. It is composed.

  According to the first aspect of the present invention, since the rear end portion of the steel pipe having the perforated bit fixed to the front end is connected to the striking / rotation transmission member and the steel pipe is driven, the perforated bit is provided. As a water supply pipe that is connected to and communicated with the water injection hole provided at the center of the steel pipe over the entire length of the steel pipe, the water injection hole of the drill bit from the rear end side of the steel pipe Therefore, it is only necessary to have a function of supplying pressure water to the pipe. Therefore, a small-diameter water supply pipe is adopted, and the excavated material discharge passage formed by the gap between the inner peripheral surface of the steel pipe and the outer peripheral surface of the water supply pipe is used. The cross-sectional space can be widened over the entire length of the steel pipe, and the drilling material intake hole provided in the drilling bit communicating with the drilling material discharge passage can be formed in a large diameter, Take-up of excavated material excavated by drill bit into intake hole Not only can be carried out smoothly and reliably, excavated material through excavated matter exhaust passage can be efficiently discharged, it can be driving operation of the steel pipe with good efficiency.

Further, the rear end of the water supply pipe is configured to be connected to the front end of the small diameter water supply connecting pipe disposed at the center of the hammering / rotation transmission member so as to be movable back and forth and to be rotatable.・ Pushing the steel pipe into the natural ground by intensively transmitting the striking rotational force only to the rear end side of the steel pipe while reliably preventing the striking rotational force from the rotation transmitting member from being directly transmitted to the water pipe. Smooth and reliable.

The steel pipe may be a single pipe, but as described in claim 2 , a leading steel pipe having a perforated bit fixed to the front end, and a rearmost side connecting the rear end to the striking / rotation transmitting member The pipe may be composed of a plurality of steel pipes including a steel pipe and an additional steel pipe that is interposed and connected between the leading steel pipe and the rearmost steel pipe. Depending on the length of the steel pipe, it is possible to form a steel pipe for reinforcing a natural ground having a desired length while sequentially adding steel pipes. Therefore, even in a narrow tunnel, a steel steel pipe for reinforcing longer than the tunnel diameter is driven into the natural ground. Can stabilize the natural ground.

Furthermore, according to the invention described in claim 2 , the front side steel pipe having the perforated bit fixed to the front end, the rear end side steel pipe connecting the rear end portion to the striking / rotation transmission member, and these front side steel pipes, In a ground-reinforced steel driven steel pipe consisting of an additional steel pipe that is interposed between and connected to the rearmost steel pipe, the length of each steel pipe is approximately equal to the length of each steel pipe in the center of the first steel pipe, the additional steel pipe, and the last steel pipe. Each of the water pipes having a length is supported on the inner peripheral surface of the steel pipe by a support bracket, and the opposite end portions of the water pipes in the adjacent steel pipes are slidable back and forth and rotatably connected. The steel pipes are connected in series, and at the same time, the front end of the water pipe in the rear steel pipe automatically fits on the same pipe axis with the rear end of the water pipe in the front steel pipe so that it can be connected easily and reliably. And therefore Despite the connection of the water pipe can not be a direct view from the outside, in which connection work of the steel pipe can be performed in efficiently and accurately.

  In addition, when the steel pipe is driven into the ground by a striking / rotating transmission member, the drill bit fixed to the front end of the steel pipe on the front side rotates and the rotational force is integrally connected to the center of the rear end surface of the drill bit. However, the rear end of this water pipe is connected to the water pipe inside the additional steel pipe so that it can rotate freely. The transmission of the rotational force to the water pipe side is cut off, so that only the leading water pipe rotates together with the drill bit and the subsequent water pipe is not twisted and deformed by the rotary force of the drill bit. The water necessary for excavation can be smoothly circulated from the water pipe on the tail steel pipe side to the water pipe side on the drilling bit side, and after the steel pipe is driven, the last steel pipe is disposed therein. Joint with water pipe And it can be reused by removing from the rear end of the steel pipe.

  Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view of a natural steel reinforcing driven steel pipe, and the natural steel reinforcing driven steel pipe has a single length. A steel pipe 1, a perforated bit 2 fixed integrally to the front end of the steel pipe 1, and a small-diameter water supply pipe 3 disposed at the center of the steel pipe 1 over the substantially entire length of the steel pipe 1, The drill bit 2 is provided with several (two in the figure) water injection holes 4 and four (four in the figure) drilled material intake holes 5 penetrating between the front and rear surfaces thereof. The front end of the water supply pipe 3 is connected to and communicated with the rear end of the water injection hole 4, and the excavated material discharge passage 6 is formed by an annular gap between the inner peripheral surface of the steel pipe 1 and the outer peripheral surface of the water supply pipe 3. A structure in which the front end of the excavated material discharge passage 6 is communicated with the rear end of the excavated material intake hole 5. It has. And this excavated material discharge passage 6 formed between the inner peripheral surface of the steel pipe 1 and the outer peripheral surface of the water supply pipe 3 has its annular space part continuous with a substantially constant area over the entire length.

  The structure of the perforated bit 2 will be described in more detail. As shown in FIGS. 2 and 3, the perforated bit 2 has an outer peripheral portion of the rear surface of the head portion 2a having a thick disc shape larger than the outer diameter of the steel pipe 1. And has an external shape in which a short cylindrical portion 2b having an inner diameter equal to the outer diameter of the steel pipe 1 is projected rearward. The short cylindrical portion 2b is fitted on the front end portion of the steel pipe 1 and the steel pipe 1 is fixed by a fixing pin 9. It is fixed to the unit. Note that the short cylindrical portion 2b of the drill bit 2 may be integrally fixed to the front end portion of the steel pipe 1 by welding instead of the fixing pin 9. Further, a circular recess 2a1 having a constant depth is formed in the front half of the head portion 2a of the perforating bit 2 from the front surface to the rear side, leaving the outer peripheral portion of the head 2a, and is left there. An annular wall portion 2a2 having a constant height protruding forward from the outer periphery of the circular recess 2a1 is formed by the outer peripheral portion.

  The annular wall portion 2a2 has an inner diameter substantially equal to the inner diameter of the steel pipe 1, and a front surface of the annular wall portion 2a2 is used as a pedestal surface of the excavation tip 7a. The mountain-shaped drilling tip 7a is projected. Similarly, a plurality of semi-spherical inner tips 7b protrude from the base surface of the circular recess 2a1 with the bottom surface of the inner excavation tip 7b as a base surface. Further, the above-mentioned several small-diameter water injection holes 4 and large-diameter drilled material intake holes 5 are provided through the chip seat surface of the circular recess 2a1 of the drill bit 2 to the rear end surface of the drill bit 2. .

  A mounting seat 2a3 for the water supply pipe 3 is projected rearward at the center of the rear surface of the drill bit 2, and a water passage hole 2a4 is formed at the center of the rear end surface of the mounting seat 2a3. While the rear ends of the holes 4 and 4 communicate with the water passage hole 2a4, the front end opening of the small-diameter water pipe 3 disposed at the center of the steel pipe 1 is the rear end surface of the mounting seat 2a3. It is brought into contact with the central portion and fixed integrally by welding or the like, and the open end communicates with the water hole portion 2a4. The water pipe 3 is supported on the inner peripheral surface of the steel pipe 1 by support brackets 8 at several locations in the length direction. Specifically, as shown in FIG. 4, the support bracket 8 has several pieces (three pieces in the figure) of support arms from the central portion 8 a having a slightly larger diameter than the water supply pipe 3 toward the inner peripheral surface of the steel pipe 1. A piece 8b is projected radially, and the water supply pipe 3 is inserted into and fixed to the central portion 8a thereof, and the outer end surface of the support arm piece 8b is fixed to the inner peripheral surface of the steel pipe 1 so that the water supply pipe 3 is fixed. The steel pipe 1 is supported over the entire length at the center.

  The steel pipe 1 is provided with injection holes 10 of a curable material penetrating the inner and outer peripheral surfaces in the tube wall at predetermined intervals in the circumferential direction and the length direction, and an engaging projection 11 having a flat rectangular shape on the outer peripheral surface of the rear end portion. Is protruding. Further, as shown in FIG. 1, a spiral or ring-shaped protrusion 12 is integrally projected on the outer peripheral surface of the steel pipe 1 to increase the pulling resistance of the steel pipe 1 after being driven into a natural ground. . It is not always necessary to provide such ridges 12.

  A striking / rotation transmitting member 20 connected to the rear end of the steel pipe 1 for transmitting the striking rotational force from the driving machine to the steel pipe 1 is formed in a cylindrical shape having a certain length as shown in FIG. The swivel body 20A and a steel pipe connecting cylinder 20B that is detachably screwed to the front end of the swivel body 20A. The swivel body 20A has a rear end portion of the small-diameter connecting pipe 30 at the center of the latter half thereof. The front screw hole 21 and the rear screw hole 22 whose rear end is opened rearward from the rear end surface of the impact / rotation transmission member 20 are screwed into the screw hole parts 21 and 22. On the other hand, the rear end of the steel pipe coupling cylinder 20B is detachably screwed to the front half of the front half of the front half through the water passage hole 23 having the front and rear ends communicated with each other. A large-diameter screw hole portion 24, and a rear end of the large-diameter screw hole portion 24 and the front screw hole portion 21. Drilling was receiving hole portion 25 is formed between, to form a drilling product discharge outlet 25a which opens to the outer peripheral surface of the swivel member 20A from the excavated material receiving hole portion within 24. The water passage hole portion 23 communicates with a water supply channel (not shown) in the operating shaft 41 and is configured to receive water from this water supply channel.

  Further, the inside of the front half of the steel pipe connecting cylinder 20B is formed in the rear end receiving cylinder 26 of the steel pipe 1, and the inner diameter of the rear half of the steel pipe connecting cylinder 20B is set to the rear end receiving cylinder of the steel pipe 1. An annular receiving member that is smaller in diameter than the inner diameter of the portion 26 and substantially the same diameter as the excavated material receiving hole portion 24, and abuts and receives the rear end surface of the steel pipe 1 at the rear end of the receiving tube portion 26. It is formed on the end face 26a. Further, the rear end portion of the steel pipe connecting cylinder 20B is formed in a screw cylinder portion 27 that is screwed into the large-diameter screw hole portion 24 of the swivel body 20A, and the screw portion 27 is formed on the front end side of the screw portion 27. An annular receiving end surface 28 protruding in the outer diameter direction from the front end is formed, and the front end surface of the large-diameter screw hole portion 24 of the swivel body 20A is brought into contact with and received by the receiving end surface 28 and driven into the screw thread. The striking force is transmitted from the receiving end face 28 to the steel pipe connecting cylinder 20B with little transmission of the striking force from the machine side, and further, the steel pipe 1 is hit from the steel connecting cylinder 20B via the receiving end face 26a. It is configured to transmit force.

  Further, an L-shaped notch locking portion 29 having a front end opened forward is formed on a part of the peripheral wall of the steel pipe receiving tube portion 26 in the steel pipe connecting cylinder 20B. An engagement projection 11 protruding from the outer peripheral surface of the rear end of the steel pipe 1 is inserted and engaged so that the rotation of the striking / rotation transmitting member 20 is transmitted to the steel pipe 1.

  The small-diameter connecting pipe 30 has an outer diameter smaller than the bore inner diameter of the drilled article receiving hole 25 of the swivel body 20A and the latter half of the steel pipe connecting cylinder 20B, and its outer peripheral surface and these drilled article receiving hole parts. 25 and the inside of the cylindrical portion of the rear half of the connecting cylinder 20B are formed in a drilled article discharge gap 6a communicating with the rear end of the drilled article discharge passage 6 in the steel pipe 1 and the small diameter connecting pipe 30. Is formed in the water passage hole 31 over its entire length, and further, a screw part 32 detachably screwed into the front screw hole 21 provided in the rear end part of the swivel body 20A. Is formed.

  Further, a cylindrical head 33 is fixed to the front end portion of the small diameter connecting pipe 30, and the cylindrical head 33 has a central hole 34a having the same diameter as the water passage hole 31 at the center. An annular buffer member 34 and a water-stop sealing material 35 having a center hole 35a into which the rear end of the water pipe 3 protruding rearward from the rear end of the steel pipe 1 is inserted in a watertight manner at the center. The interior is in a state where the water-stop seal 35 is superposed on the front and back. The rear portion of the cylindrical head 33 is attached to the outer peripheral surface of the front end portion of the small diameter connecting tube 30 with the buffer member 34 in contact with the front end surface of the small diameter connecting tube 30.

  Next, a method for driving the steel pipe 1 into the ground using the striking / rotation transmission member 20 in which the small diameter connecting pipe 30 is housed will be described. As shown in FIG. 6, the drifter 40 in the steel pipe driving machine disposed in the tunnel has a striking mechanism (not shown) for striking the rear end surface of the operating shaft 41 protruding from the front end surface of the drifter 40 and the operation. A rotating mechanism (not shown) for rotating the shaft 41 is provided. The operating shaft 41 is screwed into the rear screw hole portion 22 of the swivel body 20A, and the tip end surface of the screw hole portion 22 is engaged. The striking / rotation transmitting member 20 is connected to the operating shaft 41 by bringing it into contact with the bottom end surface.

  On the other hand, the rear end portion of the steel pipe 1 is inserted into the steel pipe receiving cylinder portion 26 in the steel pipe coupling cylinder 20B of the hammering / rotation transmission member 20, and the engaging projection protruding from the outer peripheral surface of the rear end portion of the steel pipe 1 11 is inserted into an L-shaped notch locking portion 29 formed at the front end of the steel pipe receiving tube 26, and the rear end surface of the steel pipe 1 is brought into contact with and received by the receiving end face 26a and the steel pipe 1 is surrounded. By rotating in the direction, the engaging protrusion 11 is engaged with the L-shaped notch engaging portion 29 in a retaining state. Further, as the rear end portion of the steel pipe 1 is inserted into the steel pipe receiving cylinder portion 26, the projecting end portion that protrudes from the rear end of the steel pipe 1 in the water supply pipe 3 disposed in the central portion in the steel pipe 1 is hit. Inserted into the center hole 35a of the water-stop sealing material 35 provided in the front end cylindrical head portion 33 of the small diameter connecting pipe 30 provided in the center of the rotation transmitting member 20 so as to be slidable back and forth, and thereafter The end surface is elastically pressed against the front end surface of the buffer member 34 so that the inside of the water supply pipe 3 communicates with the front end of the water passage hole 31 of the small diameter connecting pipe 30.

  In this state, the front end face of the drill bit 2 attached to the front end of the steel pipe 1 is brought into contact with the wall surface from the circumferential wall surface of the tunnel, and is then rotated against the operating shaft 41 of the drifter 40. When the drifter 40 is moved forward while applying force, the rotation of the operating shaft 41 is caused by the L-shaped notch formed in the steel pipe receiving cylinder portion 26 of the hammering / rotation transmission member 20 via the hammering / rotation transmission member 20. It is transmitted to the steel pipe 1 through the engaging projection 11 engaged with the stop portion 29, and the striking force of the operating shaft 41 is rearward in the striking / rotation transmitting member 20 receiving the front end surface of the operating shaft 41. The impact is transmitted to the swivel body 20A of the striking / rotation transmitting member 20 through the bottom end face of the side screw hole portion 22.

  Further, the swivel body 20A is transmitted to the steel pipe connection cylinder 20B via the receiving end face 28 on the outer peripheral surface side of the steel pipe connection cylinder 20B receiving the front end face of the swivel body 20A, and the steel pipe connection cylinder 20B. A drilling tip 7a projecting from the front end surface of the drill bit 2 is transmitted to the steel pipe 1 which is received by the rear end surface of the receiving end surface 26a via the inner end surface receiving end surface 26a. 7b, the steel pipe 1 is driven to a predetermined depth while excavating the natural ground.

  When the steel pipe 1 is placed, water is supplied to the water passage portion 23 in the swivel body 20A of the impact / rotation transmission member 20 through the water supply passage in the operation shaft 41, and the small diameter connecting pipe is supplied from the water passage portion 23. Through the 30 water holes 31, the water pipe 3 in the steel pipe 1 is circulated through the water pipe 3 to inject water from the water injection hole 4 of the drilling bit 2 onto the drilling surface of the drilling bit 2, and the drilling tips 7a and 7b of the drilling bit 2 The excavated material excavated by the pipe 2 is fed into the excavated material discharge passage 6 between the steel pipe 1 and the water supply pipe 3 through the excavated material intake hole 5 provided in the drill bit 2, and flows through the discharge passage 6 to It flows out from the rear end of the opening into the excavated material discharge gap 6a in the impact / rotation transmission member 20, and is discharged from the excavated material receiving hole 25 to the outside through the discharge port 25a.

  In this way, the steel pipe 1 is driven on the ground while applying a striking rotational force, but the front end of the drill bit 2 is provided with a circular recess 2a1 surrounded by an annular wall 2a2. There is provided a drilled material intake hole 5 communicating with the drilled material discharge passage 6 in the steel pipe 1 in the circular recess 2a1, and the drilled material discharge passage 6 is formed in a wide passage having substantially the same cross section over the entire length. Therefore, the excavated material excavated by the drill bit 2 is once taken into the circular concave portion 2a1, and then flows out of the circular concave portion 2a1 to the wide excavated material discharge passage 6 without flowing out to the outside by the annular wall portion 2a2. It is possible to smoothly and surely enter the excavated material discharge passage 6 in the steel pipe 1 from the excavated material intake hole 5 formed in the corresponding large-diameter hole, and accordingly, between the outer peripheral surface of the steel pipe 1 and the excavated hole. There is a risk that the excavated material will enter the gap and clog the gap. Throat eliminated, it is possible to implant steel pipe 1 is carried out efficiently and reliably.

  Thus, after the steel pipe 1 is driven to a predetermined depth in the natural ground, the engaging projection 11 protruding from the rear end portion of the steel pipe 1 is formed by rotating the striking / rotation transmitting member 20 in the opposite direction. The hammering / rotation transmission member 20 is detached from the L-shaped notch locking portion 29 and the hammering / rotation transmission member 20 is removed from the steel pipe 1. FIG. 7 is a simplified longitudinal side view showing a state in which the steel pipe 1 is driven into a natural ground. After that, the rear end portion of the steel pipe 1 protruding from the wall surface of the tunnel is sealed with a curable material injection cap (not shown), and curable such as cement milk or urethane resin liquid is supplied through the injection hose connected to this cap. When the material is supplied into the steel pipe 1, the hardenable material fills the steel pipe 1 and is injected into the ground around the steel pipe from the injection hole 10 provided in the pipe wall of the steel pipe 1 and the drilled bit 2 is excavated. It is also injected into the ground from the intake hole 5 and the ground is stabilized by hardening of the curable material.

  The ground steel reinforcing driven steel pipe is formed from a single steel pipe 1 having a certain length. However, as shown in FIG. 8, for example, a drill bit 2 is fixed to the front end. A leading steel pipe 1A, a rearmost steel pipe 1B projecting engagement projections 11 to be connected to the impact / rotation transmission member on the outer peripheral surface of the rear end, and the first steel pipe 1A and the rearmost An additional steel pipe 1C that is interposed between and connected to the side steel pipe 1B may be used.

  Specifically, the front side steel pipe 1A has a perforated bit 2 fixed integrally at the front end thereof, and a small diameter water supply pipe 3A having a length substantially equal to the length of the front side steel pipe 1A is disposed in the center. One or several places of the water pipe 3A are supported at the center of the support bracket 8 whose outer end is fixed to the inner peripheral surface of the steel pipe 1A, and the front end opening of the water pipe 3A is further centered on the rear surface of the drill bit 2 It is fixed to the rear end of the water injection hole 4 provided in the drill bit 2 by abutting against the center of the rear end surface of the mounting seat 2a3 projecting rearward at the center and fixed integrally by welding or the like. While communicating with the rear end water hole 2a4 of the mounting seat 2a3 communicated, the rear end of the water pipe 3A protrudes rearward from the rear end of the steel pipe 1A and the inner periphery of the rear end of the steel pipe 1A. The screw hole 13 is provided on the surface.

  Further, the rearmost steel pipe 1B is formed of a short steel pipe as long as it can connect between the additional steel pipe 1C and the hit / rotation transmission member 20 described above, and a screw portion on the outer peripheral surface of the front end portion thereof. 14 and a short water supply pipe 3B having a length substantially equal to the length of the rearmost steel pipe 1B is arranged in the center so that its rear end protrudes backward from the rear end of the steel pipe 1B. The water pipe 3B is supported on the center of the support bracket 8 whose outer end is fixed to the inner peripheral surface of the steel pipe 1B. Further, the front end of the water pipe 3B is located in the center of the additional steel pipe 1C described below. A diameter-expanded connection port portion 3b that is slidably movable back and forth through the seal member 17 and rotatably connected to the rear end portion of the water supply pipe 3C disposed on the pipe, that is, a structure that can be connected by an inlay joint.

  On the other hand, an additional steel pipe 1C having a fixed length that is integrally connected and interposed between the front side steel pipe 1A and the rearmost side steel pipe 1B is a screw on the front end part outer peripheral surface of the front end steel pipe 1A on the inner peripheral surface of the rear end part. A screw part 15 is formed to be screwed into the hole part 13 and is formed in a screw hole part 16 for screwing the front end screw part 14 of the rearmost steel pipe 1B to the inner peripheral surface of the rear end part. A water supply pipe 3C having a length substantially equal to the length of the additional steel pipe 1C is disposed in the section, the water supply pipe 3C is slightly shifted rearward, the rear end portion is added, and the rear end of the steel pipe 1C is projected rearward. In such a state, several places are supported by the center portion of the support bracket 8 whose outer end is fixed to the inner peripheral surface of the steel pipe 1C, and the front end portion of the water supply pipe 3C is supported by the water supply pipe 3A in the top side steel pipe 1A. The diameter-expanded connection port portion 3c is connected to the rear end portion of the rear end portion through a sealing material 18 so as to be slidable forward and backward and rotatable. , And a connectable structure spigot joint. A plurality of curable material injection holes 10 are provided in the pipe wall of the additional steel pipe 1C.

  The water supply pipes 3A to 3C arranged in the steel pipes 1A to 1C are formed to have the same diameter, and the structure of the drill bit 2 and the support bracket 8 is the same as that described in the above embodiment. Since they are the same, the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

  In order to drive the ground-steel reinforcing driven steel pipe configured as described above into a natural ground where the ground or the like is present, first, the rearmost steel pipe 1B is connected to the leading steel pipe 1A via one additional steel pipe 1C. At this time, when the front end screw hole 15 of the steel pipe 1C is screwed and connected to the rear end screw hole 13 of the front side steel pipe 1A, the water supply pipe of the steel pipe 1C is added to the rear end of the water supply pipe 3A of the front side steel pipe 1A. The 3C front end enlarged diameter connecting port 3c is automatically connected at the same time so as to cover it. Similarly, when the front end screw portion 14 of the rearmost steel pipe 1B is screwed and connected to the rear end screw hole 16 of the additional steel pipe 1C, the rear end steel pipe 1B is connected to the rear end of the water supply pipe 3C of the additional steel pipe 1C. At the same time, the connection is automatically made in such a manner that the front end enlarged diameter connection port 3b of the water pipe 3B is covered.

  Next, the ground steel reinforcing driven steel pipe composed of the connecting steel pipes 1A to 1C is driven from the inside of the tunnel toward the natural ground using the steel pipe driving machine in the same manner as in the above embodiment. That is, after connecting the swivel body 20A of the hammering / rotation transmission member 20 to the operating shaft 41 protruding from the front end surface of the drifter 40 in the steel pipe driving machine, the pipe receiving in the steel pipe connecting cylinder 20B of the hammering / rotation transmission member 20 is performed. The rear end portion of the rearmost steel pipe 1B is inserted into the cylindrical portion 26, and the engaging projection 11 protruding from the outer peripheral surface of the rear end portion of the steel pipe 1B is formed at the front end portion of the steel pipe receiving cylindrical portion 26. A small diameter connection in which the rear end protruding portion of the water supply pipe 3B in the rearmost steel pipe 1B is disposed in the center of the impact / rotation transmission member 20 while being inserted into and engaged with the L-shaped notch locking portion 29. A rear end face is elastically pressed against the front end face of the buffer member 34 through the center hole 35a of the water-stop sealing material 35 provided in the front end cylindrical head portion 33 of the pipe 30 so as to be slidable back and forth. The inside of the water supply pipe 3 is communicated with the front end of the water passage hole 31 of the small diameter connection pipe 30. The structure of the striking / rotation transmission member 20 and the small-diameter connecting pipe 30 and the connection mode of the rearmost steel pipe 1B to the striking / rotation transmission member 20 are the same as the structures shown in FIGS. 5 and 6 in the above embodiment. Therefore, detailed description is omitted.

  After connecting the rearmost steel pipe 1B of this ground reinforcement steel pipe to the impact / rotation transmission member 20, the impact rotational force is applied to the operating shaft 41 of the drifter 40 via the steel pipes 1A to 1C. The steel pipe for reinforcing natural ground is driven into the natural ground by advancing the drifter 40 while transmitting it to the drill bit 2. At this time, from the water supply passage in the operating shaft 41 to the water supply pipe 3B of the rearmost steel pipe 1B through the water passage hole 23 in the swivel body 20A of the impact / rotation transmission member 20 and the water passage hole 31 of the small diameter connection pipe 30. Drill water from the water injection hole 4 of the perforation bit 2 through the water supply pipe 3C in the additional steel pipe 1C and the water supply pipe 3A in the front side steel pipe 1A that are sequentially connected to the water supply pipe 3B. Water is sprayed on the surface, and the inner peripheral surface of the steel pipes 1A to 1C and the water supply pipe 3A to the drilled article drilled by the drilling tips 7a and 7b of the drill bit 2 through the drilled article intake hole 5 provided in the drill bit 2 It is fed into the excavated material discharge passage 6 formed in the space between the outer peripheral surfaces between 3C, and the excavated material discharge gap 6a in the striking / rotation transmission member 20 and the excavated material receiving hole 25 from the inside of the discharge passage 6 It is discharged outside through the discharge port 25a.

  The supply of the hardenable material to the inside of the ground reinforcement steel pipe, the filling, and the injection of the hardenable material into the natural ground from the injection hole 11 provided in the pipe wall of the additional steel pipe 1C in the steel pipe are as described above. It is the same.

  The length of the ground-steel reinforcement driven steel pipe consisting of the first side steel pipe 1A, one additional steel pipe 1C, and the last side steel pipe 1B is formed so that it can be driven into the natural ground by a driving machine in a narrow tunnel. If this depth alone is not sufficient to stabilize the ground due to the depth of the ground drive, the additional steel pipe 1C is added to achieve the desired drive length even from within a narrow tunnel. is doing.

  That is, after the steel pipe 1C for this ground reinforcement is added to the ground until the rear end of the steel pipe 1C protrudes from the wall surface of the tunnel, the rearmost steel pipe 1B connected to the steel pipe 1C is connected. Is removed from the rear end of the additional steel pipe 1C, and then the front end screw portion 15 of the additional steel pipe 1C having the same shape and the same structure as the additional steel pipe 1C is connected to the rear end screw hole 16 of the additional steel pipe 1C. . At this time, the front end enlarged connection port portion 3c of the water supply pipe 3C in the additional steel pipe 1C connected to the additional steel pipe 1C is automatically connected to the rear end portion of the water supply pipe 3C in the inserted additional steel pipe 1C by an inlay joint. Is done.

  In this way, after connecting a new extension steel pipe 1C, the rearmost steel pipe 1B is again connected to the rear end of the extension steel pipe 1C, and at the same time, the water supply pipes 3B and 3C in these steel pipes are also connected by an inlay joint. After that, the rear end portion of the rearmost steel pipe 1B is connected to the hammering / rotation transmission member 20, and the punching bit 2 is given through the water pipe connected in series in the steel pipe while giving the hammering rotational force to the operating shaft 41 of the drifter 40. Then, water is ejected from the water injection hole 4 to the excavation surface, and the excavated material is expelled through the excavated material discharge passage 6 in the steel pipe, and the ground steel reinforcing driven steel tube is driven in the same manner as described above. FIG. 9 is a simplified side view showing a state in which two additional steel pipes 1C and 1C are driven into a natural ground.

  When this ground reinforcement steel pipe is driven into the ground by the impact / rotation transmission member, the drill bit 2 fixed to the front end of the front side steel pipe 1A rotates and the rotational force is applied to the rear surface of the drill bit 2 It is transmitted to the water pipe 3A, which is fixed integrally, but the rear end of this water pipe 3A is added and inserted into the tip connection port 3c of the water pipe 3C in the steel pipe 1C so that it can slide back and forth and rotate freely. Therefore, the transmission of rotational force to the water supply pipe 3C in the steel pipe 1C is cut off from the water supply pipe 3A in the front side steel pipe 1A, and therefore only the front side water supply pipe 3A rotates integrally with the drill bit 2. There is no possibility that the subsequent water supply pipes 3B and 3C are twisted and deformed by the rotational force of the drill bit 2.

  After that, by adding several additional steel pipes 1C as necessary, a ground-reinforcing steel pipe of a predetermined length is formed and driven into a natural ground to a predetermined depth. The ground is stabilized by supplying and filling the curable material and injecting the curable material into the natural ground through the injection hole 10 provided in the pipe wall of each additional steel pipe 1C and hardening it. In addition, after the completion of the driving of this ground reinforcement steel pipe, the rearmost steel pipe 1B is removed from the rear end of the additional steel pipe 1C together with the water pipe 3B inside and used for driving the next ground steel reinforcement driving steel pipe. To do.

A partially omitted vertical side view of a cross section of the upper half of a steel pipe for reinforcing natural ground. The longitudinal side view of the perforated bit part. The front view of a drill bit. The longitudinal cross-sectional front view which shows the support structure of a water pipe. The vertical side view of a hit | damage and rotation transmission member. The some simple vertical side view which shows the steel pipe driving state by a drifter. The simple vertical side view of the steel pipe which shows the state driven into the natural ground. The partially abbreviated vertical side view showing another emplaced steel pipe for reinforcing ground according to the present invention. The simplified side view which shows the state which driven the two extension steel pipes into the natural ground.

Explanation of symbols

1 Steel pipe
1A Steel pipe on the front side
1B Rearmost steel pipe
1C Additional steel pipe 2 Drilling bit 3 Water supply pipe 4 Water injection hole 5 Drilled article intake hole 6 Drilled article discharge passage 8 Support bracket
10 Injection hole
11 Engagement protrusion
20 Stroke / rotation transmission member
30 Water supply small diameter connection pipe

Claims (2)

A steel pipe configured to connect the rear end portion to the striking / rotation transmission member, a drill bit integrally fixed to the front end of the steel pipe, and a central portion of the steel pipe disposed over the entire length of the steel pipe. The perforated bit is provided with a water injection hole penetrating between the front and rear surfaces and a drilled material intake hole, and the front end of the water supply pipe is connected to and communicated with the rear end of the water injection hole. The drilling material intake hole is communicated with a drilling material discharge passage formed by a gap between the inner peripheral surface of the steel pipe and the outer peripheral surface of the water pipe, and the rear end of the water pipe is further struck and rotated as described above. A ground-steel-reinforcing steel pipe that is configured to be connected to a front end portion of a small-diameter water supply pipe disposed at a central portion in a transmission member so as to be movable back and forth and to be rotatable . The steel pipe is interposed and connected between the front side steel pipe with a drill bit fixed to the front end, the rear side steel pipe that connects the rear end part to the striking / rotation transmission member, and the front side steel pipe and the rear side steel pipe. In the central part of the leading steel pipe, the additional steel pipe, and the last steel pipe, a water supply pipe having a length substantially equal to the length of each steel pipe is provided by the support brackets in the inner peripheral surface of the steel pipe. The ground mountain according to claim 1, wherein the opposite end of the water pipe in the adjacent steel pipe is slidably connected back and forth and rotatably. Steel tube for reinforcement.

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