JP5396262B2 - Face auxiliary structure, inflow prevention structure and face auxiliary construction method - Google Patents

Description

  The present invention relates to a face auxiliary structure, an inflow prevention structure, and a face auxiliary construction method.

  Conventionally, in the construction of a mountain tunnel, when a bad ground with unconsolidated or cracks appears, an auxiliary method is often selected as a countermeasure work for stabilizing the face and suppressing the preceding displacement. For the purpose of preventing the crest of the top and suppressing the settlement of the ground surface, the injection material is generally injected into a steel pipe placed near the excavation site, and the injection material is injected into the ground from the hole provided in the steel pipe. An injection-type long ground reinforcement method that permeates water is selected as an auxiliary method.

  In the injection-type long ground reinforcement method, when the non-widening method that does not require widening of the excavation section and can be constructed at any position is adopted, the steel support and the steel pipe interfere with each other for about 3 m from the placement surface. Therefore, the steel pipe of that part is removed every excavation cycle. The inside of the removed steel pipe is in a state in which the steel material and members such as an injection material and an injection tube are integrally fixed and are landfilled as mixed industrial waste. In addition, a method has been proposed in which the steel pipe after removal is divided in the vertical direction to remove the injected material inside (see, for example, Patent Document 1).

JP 2004-183400 A

  However, processing the removed steel as mixed industrial waste is problematic from the viewpoint of reducing the volume of landfill disposal. In addition, it takes a lot of cost and time to separate the steel material, which is the main resource for recycling, from the injection tube, the injection material, and the like fixed inside the steel material. Furthermore, removing the improved part of the natural ground together with the steel pipe in the part that interferes with the steel support works is also a factor that reduces the effect of the auxiliary method.

  The present invention has been made in view of the above-described problems, and its purpose is to easily separate the constituent parts of the removed portion to be removed in order to avoid interference with the support and use it as a resource. It is to provide an auxiliary structure for the working face, an inflow prevention structure, and an auxiliary method for the working face.

In order to achieve the above-described object, the first invention is used in a method of stabilizing a face by installing a tubular member from the tunnel face into the ground, and the terminal side is placed in the face and the tip side is placed in the ground. a tubular member, and a bag disposed inside the tubular member, provided separately from the the bag at both ends of the bag, the holding member having a rubber member in contact with the inner peripheral surface of the tubular member A tube injection tube that passes through the holding member and communicates with the bag, and an injection material that penetrates the bag and the holding member and communicates with the space on the distal end side of the tubular member. And an inflow preventing structure installed inside the tubular member, and inflating the bag body by injecting fluid into the bag body using the bag body injection tube. The inside of the tubular member is closed by In the state where the tubular member is divided into an injection section and a non-injection section by the inflated bag body and the holding member, an injection material is injected into the injection section using the injection material injection tube, and the non-injection section is used. It is an auxiliary structure of the working face characterized by removing the injection section.

  In the auxiliary structure for the face according to the first invention, the inflow prevention structure is installed in the tubular member installed in the natural ground, and the tubular member is divided into the injection section and the non-injection section by the inflow prevention structure. Since the injection material is not injected into the non-injection section, the vicinity of the end of the tubular member can be easily cut and removed. Moreover, each component member of a removal part can be isolate | separated easily.

The second invention is the inflow preventing structure that is disposed within the tubular members used in order to stabilize the working face, and the bag body, provided separately from the the bag at both ends of the bag A holding member having a rubber member in contact with the inner peripheral surface of the tubular member, a bag body injection tube passing through the holding member and communicating with the bag body, and penetrating the bag body and the holding member. An inflow preventing structure comprising: an injection material injection tube communicating with a space on the distal end side of the holding member of the tubular member.

  If the inflow preventing structure of the second invention is used, after the tubular member is closed with the bag, the injection material is injected into the space on the tip side from the holding member by injecting the injection material with the injection material injection tube. can do.

According to a third aspect of the present invention, there is provided a method of stabilizing a face by installing a tubular member in a natural ground from a tunnel face, a tubular member in which a terminal side is provided in the face and a tip side is provided in the natural ground, a bag body, and the bag body both ends the bag and is provided separately on a holding member having a rubber member in contact with the inner peripheral surface of the tubular member, the first bag member which communicates through said retaining member in said bag body An injection tube and a first injection material injection tube that penetrates through the bag body and the holding member and communicates with the space on the distal end side of the holding member of the tubular member, and is installed inside the tubular member A step (a) of installing the tubular member on the ground using the auxiliary structure of the face having the first inflow prevention structure formed, and the bag body using the first bag body injection tube By injecting fluid into the bag and inflating the bag. A step (b) of closing the inside of the tubular member, and dividing the inside of the tubular member into an injecting section and a non-injecting section by the inflated bag body and the holding member, and using the first injection material injecting tube. And a step (c) of injecting an injection material into the injection section and a step (d) of removing the non-injection section.

  In the third aspect of the invention, the nth inflow prevention structure (n ≧ 2) is installed at a predetermined location in the injection section as necessary, and the nth inflow prevention using the nth bag injection tube. By injecting fluid into the bag having the structure, the injection section is divided into a plurality of sections. In this case, in the step (c), the injection material is injected into an arbitrary section of the plurality of sections using the nth injection material injection tube. In the step (c), the injection material is injected in an arbitrary order into an arbitrary section among the plurality of sections.

  In the auxiliary method of the working face of the third invention, the inflow prevention structure provided in the tubular member installed in the natural ground is used, and the tubular member is divided into the injection section and the non-injection section, and then the injection material is injected only into the injection section. Inject. Since the injection material is not injected into the non-injection section, the non-injection section of the tubular member can be easily cut and removed. Moreover, each structural member of a removal part can be isolate | separated easily, and a tubular member can be utilized as a resource.

  ADVANTAGE OF THE INVENTION According to this invention, the component part of the removal part removed in order to avoid interference with a support work can be isolate | separated easily, and the auxiliary structure of a face, an inflow prevention structure, and the auxiliary method of a face that can be utilized as a resource can be provided. .

The figure which shows the outline | summary of the inflow prevention structure 5 installed in the steel pipe 1 for injection type long ground reinforcement Cross section in the axial direction of the steel pipe 1 for injection type long ground reinforcement The figure which shows each process in the auxiliary method of a face using the injection-type long natural mountain reinforcement steel pipe 1 Cross section in the axial direction of the upper half of the tunnel The figure which shows the example of the long mirror bolt 51

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of an inflow prevention structure 5 installed in a steel pipe 1 for injection-type long ground reinforcement. FIG. 1A is a cross-sectional view in the axial direction of the injection-type long ground reinforcement steel pipe 1 in the vicinity of the installation position of the inflow prevention structure 5. FIG. 1B is a perspective view of the rubber member 13, and FIG. 1C is a perspective view of the sponge member 15.

  As shown in FIG. 1, an injection-type long ground reinforcement steel pipe 1 that is an auxiliary structure of a face is composed of a steel pipe 3 that is a tubular member and an inflow prevention structure 5. The inflow prevention structure 5 includes a bag body 7, a rubber member 13, a sponge member 9, a sponge member 15, a bag body injection tube 19, an injection material injection tube 17, and the like. The inflow prevention structure 5 is installed inside the steel pipe 3.

  The bag body 7 has such a size that the steel pipe 3 can be closed at the time of expansion, and becomes a main closing object that separates the injection section and the non-injection section inside the steel pipe 3. The rubber member 13 is located on both sides of the bag body 7 and serves as an auxiliary blockage for further improving the blockage in addition to the blockage by the bag body 7. The rubber member 13 is, for example, a frustoconical member whose maximum diameter is about the inner diameter of the steel pipe 3, and the end portion 14 contacts the inner peripheral surface 11 of the steel pipe 3. The rubber member 13 has a hole 21 and a hole 23 penetrating in the axial direction.

  The sponge member 9 is disposed at both ends of the bag body 7 and protects the bag body 7 and absorbs the injection material that has passed through between the inner peripheral surface 11 and the rubber member 13 from the injection side inside the steel pipe 3, By expanding, it becomes an auxiliary occluding material for enhancing the occlusive property. The sponge member 9 has a plurality of holes having the same cross-sectional area at positions corresponding to the holes 21 and 23 of the rubber member 13. The sponge member 15 is an annular member, and the rubber member 13 is disposed inside the hole 27. As with the sponge member 9, the sponge member 15 also absorbs the injected material that has passed through the space between the inner peripheral surface 11 and the rubber member 13 from the injection side inside the steel pipe 3 and expands, thereby assisting to increase the blocking property. It becomes an obstruction.

  The bag body injection tube 19 passes through the hole 21 of the rubber member 13 a on the terminal side and the hole (not shown) of the sponge member 9 and communicates with the bag body 7. The injection material injection tube 17 passes through the bag 7, the holes 23 of the rubber members 13 a and 13 b at both ends of the bag 7, and the hole (not shown) of the sponge member 9, and the rubber member at the tip side of the steel pipe 3. It communicates with the space on the tip side from 13b. The bag body injection tube 19 and the injection material injection tube 17 are installed according to the number of inflow prevention structures 5 installed in the steel pipe 3.

  FIG. 2 is a sectional view in the axial direction of the injection-type long ground reinforcement steel pipe 1. As shown in FIG. 2, the steel pipe 3 constituting the injection-type long ground reinforcement steel pipe 1 is formed by connecting a terminal pipe 3-1, two intermediate pipes 3-2 and a tip pipe 3-3. The A bit 29 is provided at the tip of the tip tube 3-3. The terminal tube 31 is non-porous and has a slit (not shown) for facilitating cutting when removed. The two intermediate tubes 3-2 and the tip tube 3-3 are provided with injection holes (not shown).

  An inflow prevention structure 5-1 is installed in the vicinity of the connecting portion between the terminal pipe 3-1 and the intermediate pipe 3-2. An inflow prevention structure 5-2 is installed in the vicinity of the connecting portion between the two intermediate pipes 3-2. An inflow prevention structure 5-3 is installed in the vicinity of the connecting portion between the intermediate tube 3-2 and the tip tube 3-3. The inflow prevention structures 5-1, 5-2, and 5-3 each have the same structure as the inflow prevention structure 5 shown in FIG. However, the number of the bag injection tube 19 and the injection material injection tube 17 penetrating the rubber member 13 and the bag body 7 differs depending on the installation position.

  The steel pipe 3 is divided into an injection section 31 and a non-injection section 33 by the inflow prevention structure 5-1. The injection section 31 of the steel pipe 3 is injected by the three inflow prevention structures 5-1, 5-2, and 5-3 into the injection section 31-on the tip side from the inflow prevention structure 5-1 and the terminal side from the inflow prevention structure 5-2. 1. It is divided into an injection section 31-2 on the tip side from the inflow prevention structure 5-2 and on the terminal side from the inflow prevention structure 5-3, and an injection section 31-3 on the tip side from the inflow prevention structure 5-3.

  The end of the bag injection tube 19-1 communicates with the bag 7 of the inflow prevention structure 5-1. The end of the injection material injection tube 17-1 penetrates the inflow prevention structure 5-1, and is an injection section 31- that is a space on the tip side from the inflow prevention structure 5-1 and on the terminal side from the inflow prevention structure 5-2. Communicate to 1.

  The end portion of the bag injection tube 19-2 penetrates the inflow prevention structure 5-1, and communicates with the bag body 7 of the inflow prevention structure 5-2. The end of the injection material injection tube 17-2 penetrates the inflow prevention structure 5-1 and the inflow prevention structure 5-2, and is located on the tip side from the inflow prevention structure 5-2 and on the terminal side from the inflow prevention structure 5-3. It communicates with the injection section 31-2 which is a space.

  The end portion of the bag injection tube 19-3 penetrates the inflow prevention structure 5-1 and the inflow prevention structure 5-2 and communicates with the bag body 7 of the inflow prevention structure 5-3. The end of the injection material injection tube 17-3 penetrates the inflow prevention structure 5-1, the inflow prevention structure 5-2, and the inflow prevention structure 5-3, and is a space on the tip side from the inflow prevention structure 5-3. It communicates with the injection section 31-3.

  Next, a description will be given of an auxiliary method of working face using the injection-type long ground reinforcement steel pipe 1. FIG. 3 is a diagram showing each step in the auxiliary working method for the face using the injection-type long ground reinforcement steel pipe 1. FIG. 3A is a diagram illustrating a process of installing the injection-type long ground reinforcement steel pipe 1 in the ground 35.

  In the step shown in FIG. 3 (a), first, the injection-type long natural ground reinforcement steel pipe 1 shown in FIG. It is installed in the natural ground 35 so that the side is arranged on the face. The injection-type long ground reinforcement steel pipe 1 is concentrated and installed on a defective ground in front from a location where it interferes with the existing support work 37. A caulking 22 made of a caulking material and cloth is attached between the vicinity of the outer peripheral face of the steel pipe 1 for reinforcing the long long ground and the ground 35 to prevent leakage at the mouth.

  Then, by injecting a fluid into the bag body of the inflow preventing structure 5-1 as the first inflow preventing structure using the bag injecting tube 19-1 as the first bag injecting tube, and expanding the bag body. The inside of the steel pipe 3 is closed, and the steel pipe 3 is divided into an injection section 31 and a non-injection section 33. Also, by injecting and inflating the fluid into the bag body of the inflow prevention structures 5-2 and 5-3 using the bag body injection tubes 19-2 and 19-3, the inside of the steel pipe 3 is closed, The injection section 31 is divided into injection sections 31-1, 31-2, and 31-3.

  After the injection section 31 is divided into three sections, the injection material is injected into the injection section 31-3 on the most distal end side using the injection material injection tube 17-3. Moreover, an injection material is inject | poured into the injection area 31-2 on the terminal side from the injection area 31-3 using the injection material injection tube 17-2. Furthermore, an injection material is inject | poured into the injection | throwing-in area 31-1 on the most terminal side using the tube 17-1 for injection material injection | pouring. At this time, the order of injection may be arbitrary. As described above, since the two intermediate pipes 3-2 and the tip pipe 3-3 constituting the injection section 31 have injection holes (not shown), the injected injection material is grounded via the injection holes. 35 penetrates.

  FIG. 3B and FIG. 3C are diagrams illustrating a process of excavating the face and removing the non-injection section 33 of the injection-type long ground reinforcement steel pipe 1. After finishing the improvement of the natural ground 35 by the process shown in FIG. 3A, the natural ground 35 is excavated to the vicinity of the position where the next support work 37 is installed, as shown in FIG. 3B. And the steel pipe 3, the injection material injection tube 17 and the bag body injection tube 19 are cut, the removal portion 41 of the injection-type long ground reinforcement steel pipe 1 is removed, and a support 37 is newly provided.

  Thereafter, as shown in FIG. 3C, a natural ground 35 is further excavated. Then, the steel pipe 3, the injection material injection tube 17 and the bag body injection tube 19 are cut at a position before the inflow prevention structure 5-1, and the removal portion 41 of the injection-type long ground reinforcement steel pipe 1 is removed. To complete. As described above, the terminal pipe 3-1 of the removal portion 41 is provided with a slit (not shown) for facilitating cutting at the time of removal.

  In FIG. 3B and FIG. 3C, the terminal pipe 3-1 that is the removed portion 41 is the non-injection section 33, and the injection material does not adhere inside. Therefore, the removal portion 41 is easily separated and separated into the steel pipe 3, the injection material injection tube 17, and the bag body injection tube 19.

  FIG. 4 shows an axial sectional view of the upper half of the tunnel. When constructing the tunnel, after excavating the tunnel while improving the natural ground 35 by each process shown in FIG. 3, the shotcrete 45 and the lining concrete 47 shown in FIG. 4 are constructed. As shown in FIG. 4, a short injection fore-poling 43 may be applied in the section where the injection-type long ground pile reinforcing steel pipe 1 is removed, depending on the degree of failure of the ground.

  Thus, in 1st Embodiment, the non-injection area | region 33 is provided in the removal plan part by the side of the terminal of the steel pipe 3. FIG. Therefore, the injection material does not adhere to the injection material injection tube 19, the bag body injection tube 17, and the steel pipe 3, which are planned to be removed, and includes all the injection tubes that have been disposed as landfills as mixed industrial waste. The removed portion 41 can be separated and recycled, and the environmental load can be reduced. Moreover, waste disposal costs can be reduced, and valuable materials such as steel pipes 3 and injection tube valves can be disposed of. Furthermore, by eliminating the injection of the injection material into the removed portion 41 with little natural ground reinforcement effect, the injection time and the amount of the injection material can be reduced, and the construction cost can be reduced.

  In 1st Embodiment, since injection pressure does not act on the terminal pipe | tube 3-1 which is the non-injection area 33, the slit processed into the steel pipe 3 for a cutting | disconnection can be made thin, and cutting | disconnection removal work is easy. Become. Further, even in a weak ground, the impact on the ground 35 when the terminal pipe 3-1 is removed is reduced, and the looseness of the ground 35 near the cut portion can be reduced.

  In the first embodiment, by constructing the injection type fore-poling 43, a higher top end collapse suppression effect can be expected. Moreover, the injection material reduced by this can be used effectively.

  In the first embodiment, the material of the steel pipe 3 is steel, but the material is not limited to this as long as it is a tubular member having the same purpose. Further, the shape and material of the rubber member 13 that is the holding member of the bag body 7 may not be as described above. The holding member may be any shape and material that can reliably prevent the positional displacement of the bag body 7 in the steel pipe 3 and function as an auxiliary closing object inside the steel pipe 3.

  In 1st Embodiment, although the inflow prevention structure 5 was provided in three places of the steel pipe 3, the number of installation of the inflow prevention structure 5 is not restricted to this. Further, the steel pipe 3 is configured by connecting the terminal pipe 3-1, the two intermediate pipes 3-2, and the tip pipe 3-3, but the configuration of the steel pipe 3 is not limited thereto.

  In FIG. 4, the case where the injection-type long ground reinforcement steel pipe 1 is constructed by the non-widening method is illustrated. However, the injection-type long ground reinforcement steel pipe 1 is constructed by the widening method or the non-widening multistage method. It is also applicable to.

  Next, a second embodiment will be described. FIG. 5 is a diagram illustrating an example of the long mirror bolt 51. FIG. 5A shows an axial sectional view of the long mirror bolt 51. As shown in FIG. 5 (a), the long mirror bolt 51, which is an auxiliary structure for the face, is composed of a steel pipe 53 and an inflow prevention structure 5a.

  The steel pipe 53 which is a tubular member is non-porous and has a slit for cutting and removing. The inflow prevention structure 5a has substantially the same structure as the inflow prevention structure 5 shown in FIG. 1, but instead of the injection material injection tube 17 and the bag body injection tube 19, the injection material injection tube 57 and the bag body injection. One tube 59 is provided for each. The injection material injection tube 57 penetrates the inflow prevention structure 5a and communicates with the space on the tip side from the inflow prevention structure 5a. The bag injection tube 59 communicates with the bag 7 of the inflow prevention structure 5a. The inflow prevention structure 5 a is disposed near the tip of the steel pipe 53 and divides the steel pipe 53 into an injection section 67 and a non-injection section 69. The bit 55 is provided at the tip of the steel pipe 53.

  FIG. 5B is a diagram showing an auxiliary method of working the face using the long mirror bolt 51. In FIG. 5 (b), a bit 55 is used to cut a hole in the ground 61, and the long mirror bolt 51 is placed in the ground 61 so that the tip side is placed in the ground 61 and the terminal side is placed on the face. Install. A caulking made of a caulking material and cloth is attached between the vicinity of the outer peripheral face of the long mirror bolt 51 and the natural ground 35 to prevent leakage at the mouth. Next, a fluid is injected into the bag body 7 of the inflow preventing structure 5a using the bag injection tube 59 to expand it, the steel pipe 53 is closed, and the steel pipe 53 is divided into an injection section 67 and a non-injection section 69. To do. Then, the injection material 63 is injected into the injection section 67 using the injection material injection tube 57. The injection material 63 exudes from the vicinity of the bit 55, fills the hole drilled in the ground 61, and is injected into the ground 61 around the steel pipe 53.

  Thereafter, the operation of excavating the face and the operation of cutting and removing the steel pipe 53, the injection material injection tube 57, and the bag body injection tube 59 in the non-injection section 69 are repeated until just before the injection section 67. The removal portion 65 of the long mirror bolt 51 is a non-injection section 69, and the injection material does not adhere inside. Therefore, the removed portion 65 is easily separated and separated into the steel pipe 53, the injection material injection tube 57, and the bag body injection tube 59.

  In the second embodiment, a non-injection section 69 is provided in a portion to be removed except for the vicinity of the tip of the steel pipe 53. Therefore, the injection material does not adhere to the injection material injection tube 57, the bag body injection tube 59, and the steel pipe 53, and all the removal portions 65 including the injection tube that has been disposed as landfill as a mixed industrial waste conventionally. Can be separated and recycled, and the environmental load can be reduced. Moreover, waste disposal costs can be reduced, and valuable materials such as steel pipe 53 and injection tube valves can be disposed of. Furthermore, the injection time and injection amount of the injection material can be reduced, and the construction cost can be reduced.

  In the second embodiment, since the injection pressure does not act on the non-injection section 69, the slit processed into the steel pipe 53 for cutting can be made thin, and the cutting and removing work becomes easy. Further, even in a weak ground, the impact on the ground 61 when the steel pipe 53 is removed is reduced, and the looseness of the ground 61 near the cutting portion can be reduced.

  In the second embodiment, the steel pipe 53 is made of steel, but the material is not limited to this as long as it is a tubular member having the same purpose. For example, when excavating a natural ground including a tubular member, a drillable material such as fiber reinforced plastic is used. Further, the shape and material of the rubber member 13 which is the holding member of the bag body 7 of the inflow preventing structure 5a may not be as described above. The holding member may be any shape and material that can reliably prevent the positional displacement of the bag body 7 in the steel pipe 53 and function as an auxiliary closing object inside the steel pipe 53.

  In 2nd Embodiment, although the inflow prevention structure 5a was provided in one front-end | tip of the steel pipe 53, the number of installation of the inflow prevention structure 5a is not restricted to this. Also, by increasing the number of inflow prevention structures 5a and the number of injection holes provided in the steel pipe 53, it is possible to perform multistage injection or injection with a limited injection section.

  In the first and second embodiments, a tubular member is installed in a natural ground and the ground is reinforced by injecting an injection material into the injection section, and then the face is excavated and the non-injection section of the tubular member is removed. However, the order of excavating the face and removing the non-injection section is not limited to that described in the first and second embodiments. After reinforcing the natural ground, the non-injection section of the tubular member may be removed and the face may be excavated.

  In the first and second embodiments, the non-injection section is provided on the end side of the tubular member and the injection section is provided on the face side. However, the arrangement of the non-injection section and the injection section is not limited thereto. In the present invention, the inside of the tubular member can be divided into a plurality of sections using the inflow prevention structure, and an arbitrary section of the plurality of sections can be set as the injection section. For example, when the position of the outstanding opening crack can be grasped by exploring the front of the face, etc., if the injection section is limited to the position of the crack, or if it is desired to improve the entire front face of the face, the injection section is minimized. It is also possible to reduce the amount of mixed waste while improving the entire ground. In the present invention, when there are a plurality of injection sections, the injection material can be sequentially injected from any injection section.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Steel pipe for injection type long ground mountain reinforcement 3, 53 ......... Steel pipe 3-1 .... Terminal pipe 3-2 ......... Intermediate pipe 3-3 ......... End pipe 5, 5-1, 5-2, 5-3, 5a ......... Inflow prevention structure 7 ......... Bag body 9,15 ......... Sponge member 13 ......... Rubber member 17, 17-1, 17-2, 17-3, 57 ......... Injection material injection tube 19, 19-1, 19-2, 19-3, 59 ......... Bag body injection tube 29, 55 ......... Bit 39, 63 ......... Injection material 31, 31- 1, 31-2, 31-3, 67 ......... Injection section 33, 69 ... ... Non-injection section 35, 61 ... ... Machiyama 41, 65 ... ... Removal part

Claims (6)

Used in the construction method to stabilize the face by installing a tubular member in the ground from the tunnel face,
A tubular member with the terminal side on the face and the tip side installed in the natural ground,
A bag placed inside the tubular member, provided separately from the the bag at both ends of the bag, a holding member having a rubber member in contact with the inner peripheral surface of said tubular member, said retaining A tube injection tube that penetrates the member and communicates with the bag, and an injection material injection tube that penetrates the bag and the holding member and communicates with the space on the distal end side of the tubular member. Comprising an inflow prevention structure installed inside the tubular member,
The tubular member is closed by inflating the bag by injecting fluid into the bag using the bag injection tube, and injecting the tubular member by the expanded bag and the holding member. An auxiliary structure for a working face, wherein an injection material is injected into the injection section using the injection material injection tube in a state divided into a section and a non-injection section, and the non-injection section is removed. The holding member further includes a sponge member capable of enhancing occlusion by absorbing and inflating an injection material that has passed between the inner peripheral surface of the tubular member and the rubber member. The auxiliary structure for a face according to claim 1. An inflow prevention structure installed inside a tubular member used to stabilize the face,
A bag,
Provided separately from the the bag at both ends of the bag, a holding member having a rubber member in contact with the inner peripheral surface of said tubular member,
A bag injection tube that penetrates the holding member and communicates with the bag;
An injection material injection tube that passes through the bag body and the holding member and communicates with the space on the distal end side of the holding member of the tubular member;
The inflow prevention structure characterized by comprising. The holding member further includes a sponge member capable of enhancing occlusion by absorbing and inflating an injection material that has passed between the inner peripheral surface of the tubular member and the rubber member. The inflow prevention structure according to claim 3. In the construction method that stabilizes the face by installing a tubular member in the ground from the tunnel face,
A tubular member with the terminal side on the face and the tip side installed in the natural ground,
A bag body, provided separately from the the bag at both ends of the bag, a holding member having a rubber member in contact with the inner peripheral surface of said tubular member, said bag through said retaining member The first bag injection tube that communicates, and the first injection material injection tube that penetrates the bag and the holding member and communicates with the space on the distal end side of the holding member of the tubular member, A first inflow prevention structure installed inside the tubular member;
Using the auxiliary structure of the face with
A step (a) of installing the tubular member on the natural ground;
A fluid is injected into the bag body using the first bag body injection tube, the inside of the tubular member is closed by expanding the bag body, and the tubular member is expanded by the expanded bag body and the holding member. A step (b) of dividing the inside into an injection section and a non-injection section;
(C) injecting an injection material into the injection section using the first injection material injection tube;
Removing the non-injection section (d);
An auxiliary method of working face, characterized by comprising: The holding member further includes a sponge member capable of enhancing occlusion by absorbing and inflating an injection material that has passed between the inner peripheral surface of the tubular member and the rubber member. The auxiliary method for a face according to claim 5.

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