JP2006226058A - Grouting construction method and injection pipe device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grouting construction method and an injection pipe device for use in the prevention of liquefaction of ground, which make the ground surely consolidated with rapidity, while preventing a collapse of an excavated hole wall by inserting the injection pipe into an oblique, horizontal or curved excavated hole, for example, in foundation ground improvement directly below an existing building. <P>SOLUTION: In the grouting construction method and grouting equipment, the ground is consolidated by injecting grout from outer-pipe ejection holes 5, 5, etc. , which are opened between adjacent packers 3 and 3; a permeable hole wall holding material 8 is mounted between the adjacent bag packers 3 and 3 of an outer wall 2 of the injection pipe 1 or a double injection pipe; and the grout is injected into the ground from the ejection holes 5, 5, etc., which are opened between the adjacent bag packers 3 and 3, through the holding material 8. Refer to Fig. 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ground injection method and an injection pipe device used, for example, to prevent liquefaction of the ground, and in particular, to improve the foundation ground directly under an existing building, etc. The present invention relates to a ground injection method and an injection pipe device that are quickly and surely consolidated while being inserted therein to prevent the drilling wall from collapsing.

  In order to improve the ground directly under the foundation of existing buildings, such as preventing liquefaction of the ground, rapid construction of large soil is usually desired. As this type of technology, a large columnar penetration source has conventionally been installed between the upper and lower bag packers, which are spaced apart from each other in the axial direction of the injection tube, and the drilling wall around the injection tube. The injection material was injected at a large discharge amount from this columnar infiltration source, and the injection material was infiltrated between soil particles at a low pressure.

  The above-mentioned conventional technology is not only economical because it is rapid construction with a large discharge rate, but also allows low-pressure soil particle infiltration at a low infiltration rate from the unit infiltration area of a large infiltration source. I was satisfied with the consolidation at the same time.

  On the other hand, in the above-mentioned conventional technology, in the case of liquefaction prevention work, it is an improvement of a large foundation ground directly under an existing building, so the injection pipe is inserted diagonally, horizontally, or inserted into a curve. Necessity such as rubbed occurs. In this case, in order to perform rapid construction by columnar penetration, it is necessary to take a long gap between the bag packers and form a long columnar space.

However, as described above, when the injection tube is installed in an oblique direction, a horizontal direction, or a curved shape, the hole wall must be formed diagonally, horizontally, or curved, and therefore, The hole wall tends to collapse and the columnar space tends to collapse.
JP 2002-167745 A Japanese Patent No. 2772637 (Japanese Patent Laid-Open No. 1-52910)

  Therefore, an object of the present invention is to inject an injection material from a long columnar space by inserting an injection pipe in an oblique direction, a horizontal direction, or a curved shape of the ground, and to inject the foundation ground directly under an existing building to prevent liquefaction. An object of the present invention is to provide a ground injection method and an injection pipe device that prevent the drilling wall from collapsing to fill a columnar space and make injection difficult and improve the above-described drawbacks of the known technology.

  In order to achieve the above-mentioned problems, according to the ground injection method of the present invention, boring is performed horizontally or obliquely in the ground to be improved, or any combination of bending and straight lines, and the obtained boring hole is injected. A plurality of bags are attached to the outer wall of the tube at intervals, and an injection tube device having an outer tube discharge port opened between the inside of the bag and the adjacent bags is inserted, and then the outside is opened inside the bag. The bag body is filled with a curable suspension from a tube discharge port and inflated to form a bag packer, and an injection material is injected from an outer tube discharge port opened between the adjacent packers to fix the ground. In the ground injecting method to be connected, a water-permeable hole wall holding material is mounted between adjacent bag packers on the outer wall of the injection pipe, and the ground material is opened from the outer pipe discharge port which opens the injection material between the adjacent bag packers through the holding material. It is characterized by being injected inside.

  Furthermore, in order to achieve the above-mentioned problem, according to the injection tube device of the present invention, it is inserted into the ground to be improved horizontally or obliquely, or inserted into a bored hole bored by arbitrarily combining bending and straight lines, An injection tube device for consolidating the ground, which is opened between an injection tube, a plurality of bags attached to the outer wall of the injection tube at intervals, and the inside of the bag and between adjacent bags. The outer tube discharge port is provided, and the bag body is filled with a curable suspension from the outer tube discharge port that is opened in the bag body and inflated to form a bag packer, and between adjacent bag packers. In an injection tube device for injecting an injection material from an outer tube discharge port to be opened and consolidating the ground, a water permeable hole wall holding material is attached to the outer wall of the injection tube between the bag packers, and the injection material is passed through the holding material From the outer tube discharge port that opens between adjacent bag packers Characterized by injecting into the board.

  In the present invention, as described above, a water-permeable hole wall holding material is mounted between upper and lower adjacent bag packers having an outer tube discharge port of the injection tube outer wall, and the injection material from the outer tube discharge port is passed through the holding material to form a columnar space. Since the outer pipe discharge port is protected by the water-permeable hole wall retaining material, the drilling wall collapses and the columnar space is buried, making it difficult to inject the pipe. Moreover, even if the injection tube is inserted in an oblique direction, a horizontal direction or a curved shape, the hole is not collapsed and the injection is achieved satisfactorily.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view for explaining the basic structure of a ground injection method and an injection pipe device according to the present invention. FIG. 2 is a cross-sectional view for explaining an injection tube device according to the present invention using a double tube double packer and a ground injection method using the injection tube device. FIG. 3 is a perspective view of a specific example of the water-permeable hole wall holding material used in the present invention. FIG. 4 is a basic schematic diagram of the ground treatment to be improved directly under the structure. FIG. 5 is an explanatory diagram showing the boring state below the structure.

  FIG. 1 is an explanatory view showing an example of a ground injection method and an injection pipe device of the present invention, and a plurality of bag bodies 4 forming a bag packer 3 are attached to an outer wall 2 of the injection pipe 1 at intervals, The outer tube discharge ports 5, 5... 5 opened in the bag body 4 and the outer tube discharge ports 5, 5... 5 opened between the adjacent bag bodies 4, 4 are provided. An injection tube device X is configured.

  In the present invention, the injection tube device X configured as described above is inserted into a drilling hole 7 provided in the ground 6. Next, a curable suspension is filled into the bag body 4 through the injection tube 1 from the discharge port 5 that is opened in the bag body 4 and inflated to form the bag packer 3. Then, the injection material is injected from the outer tube discharge port 5 opened between the adjacent bag packers 4 and 4 through the injection tube 1, for example, the inner tube 12 of FIG. The ground 6 is consolidated.

The bag body 4 is composed of a water-permeable bag body that passes through a part of the curable suspension. As this type of water permeable bag, woven fabric, non-woven fabric, water permeable synthetic resin, net, drain material and the like are used. Specifically, for example, spunbond nonwoven fabrics G2040 and G2050 manufactured by Toray Industries, Inc. are used. G2040 has a basis weight of 40 (g / m ² ), a thickness of 0.16 (mm), a tensile strength of 16 (kgf / 5 cm ² ), a width of 8 (kgf / 5 cm ² ), and a water permeability of 2.13 × 10 ² (cm G2050 has a weight per unit area of 50 (g / m ² ), a thickness of 0.21 (mm), a tensile strength of 20 (kgf / 5 cm ² ), a width of 10 (kgf / 5 cm ² ), and water permeability. The coefficient is 3.14 × 10 ² (cm / sec). In addition, a water-impermeable sheet, a rubber bag, or the like can be used, but it is preferable to have water permeability because the suspension is tightly packed by pressurization and becomes a strong packer.

  Further, the bag body 4 has a diameter larger than the diameter of the hole 7. Specifically, the bag body 4 preferably has a diameter that is 1.2 to 5.0 times the diameter of the hole. When the bag body 4 is filled with the suspension and inflated to form the bag packer 3, the diameter of the bag body 4 is larger than the diameter of the hole 7. Consolidated. As a result, the dense underground packer 10 in which the injected material is difficult to penetrate into the ground region around the bag packer 3 is formed.

  When the diameter of the bag body 4 is smaller than 1.2 times, the hole wall 9 around the bag packer 3 is less compacted. Moreover, when larger than 5.0 times, the bag body 4 will be easily torn by the filling pressure. That is, the bag body 4 is not evenly tensioned, and the bag body portion that contacts the weak portion of the surrounding soil layer is pressurized non-uniformly and the bag body is likely to be broken.

  The curable suspension used in the present invention includes any suspension such as a cement suspension. When such a suspension is filled in a permeable bag 4 made of nonwoven fabric with an average of 0.05 mm, for example, and inflated to form a bag packer 3, a suspension containing particles finer than a particle size of 0.05 mm The liquid passes from the bag body 4 to the outside and penetrates and hardens on the compacted hole wall. At this time, the inside of the bag body 4 is hardened at a high concentration to form a high-strength bag packer 3 and a dense and strong underground packer (in the ground) in which the injected material does not easily penetrate into the ground region around the bag packer 3. Packer) 10 is formed. That is, for example, when the curable suspension in the bag 4 made of non-woven fabric is pressurized, a part of this penetrates from the bag 4 to the external ground and firmly solidifies the ground, 10 is formed.

  In this state, from the outer tube discharge port 5 between the adjacent bag packers 3, 3, the rubber sleeve 15 is expanded and passed through a large columnar space held by the water permeable hole wall holding material 8, and further through the hole wall 9. When the injection material is injected into the ground 6, the injection material is blocked by the underground packer 10 in the ground 6 and does not deviate, and penetrates into the injection target soil layer in the vertical direction in the direction of the arrow, farther, As a result, it is possible to reduce the number of holes by widening the hole interval (injection hole interval), which simplifies the injection operation and is economically advantageous.

  In order to further increase the advantages of the present invention described above, when the length of the bag body 4 is L and the gap between the adjacent bag bodies 4, 4 is A, the relationship is A ≦ 2L. Is preferred. By maintaining such a relationship, the above-described advantages of the present invention are further increased.

  The feature of the present invention resides in that a water permeable hole wall holding material 8 is mounted between the bag bodies 4, 4 adjacent to the outer wall 2 of the injection tube 1. The injection material is injected into the ground 6 through the holding material 8 from the outer tube discharge ports 5, 5... As the injection material, active silica, colloidal silica, silica sol or the like is used.

  In the present invention, by mounting the water permeable hole wall holding material 8, the hole wall 9 does not collapse even if the gap between the adjacent bag packers 3 and 3 is long. Therefore, a large columnar space can be maintained, low-pressure injection can be performed with a large discharge amount, and a wide range of permeation injection with a large injection hole interval can be achieved.

  In addition, although the water-permeable hole wall holding material 8 used for this invention may be manufactured from a net | network body, other woven fabric, a nonwoven fabric, water-permeable synthetic resin, various drain materials, a synthetic resin fiber, and a vegetable fiber are made into mat shape. 3 can be manufactured from various materials having water permeability such as a molded material.

  FIG. 2 shows an injection pipe device X of the present invention using a double pipe double packer 1 as the injection pipe 1 and a ground injection method using the same. In FIG. 2, the double tube double packer 1 includes an outer tube 11 and an inner tube 12. The inner tube 12 is provided with an inner tube discharge port 13 on the tube wall at the tip, and is provided with a pair of packers 14 and 14 so as to sandwich the inner tube discharge port 13, and is movable to the left and right.

  First, the inner tube 12 is moved to match each discharge port 5 of the bag body 4, and the rubber sleeve 15 is expanded from each of the discharge ports 5, 5. The bag packer 3 is formed by filling and inflating. At this time, since the diameter of the bag body 4 is larger than the diameter of the hole 7, the hole wall 9 around the packer is consolidated by the bag packer 3. Moreover, since the bag body 4 is a water-permeable bag body, the curable suspension that has passed from the bag body 4 penetrates and hardens into the compacted hole 9 and thereby hardens the interior of the bag body 4 at a high concentration. In addition to forming the high-strength bag packer 3, the dense underground packer 10 in which the injected material is difficult to penetrate into the ground 6 region around the bag packer 3 is formed.

  After forming the ground inner packer 10, the inner tube 12 is aligned with the discharge port 5 between the adjacent bag packers 3, 3, and the inner tube 12 and the discharge port 5 are passed through the inner tube 12. When the injected material is injected from the drilling wall 9 into the ground 6 through the retained columnar space, the injected material does not deviate in the left-right direction, and penetrates widely into the soil layer to be injected in the vertical direction farther in the direction of the arrow. Further, it is possible to reduce the number of holes by widening the hole interval (injection hole interval), which simplifies the injection operation and is economically advantageous.

  1 and 2, a plurality of discharge ports 5 between adjacent bag packers 3 and 3 may be provided. In this case, the plurality of discharge ports 5 are provided so as to be positioned in the pair of packers 14 and 14 of the inner tube 12, thereby enabling simultaneous injection from the plurality of discharge ports 5. Of course, the discharge ports 13 of the inner tube 12 may be sequentially injected into the plurality of discharge ports 13 respectively. In the present invention, the farthest bag packer 3 shown in FIGS. 1 and 2 is not necessarily required. In FIG. 2, an inner tube packer 14 is a packer that can be expanded and contracted. Even if the packer is formed by expansion by a fluid pressure from a packer fluid flow path (not shown) provided in the inner tube. Good.

  FIG. 4 is a basic schematic diagram of the ground treatment to be improved directly under the structure. First, as shown in FIG. 4, it is bent into the ground 6 from the ground surface 17 near the ground 6a to be improved directly under the immovable structure 16 such as a building, a waste disposal site, a reservoir, a reservoir, or the like. Or a combination of bending and straight lines, for example, in FIG. 4, first bend obliquely, then straight to the ground 6 a to be improved immediately below the structure 16, and then further bend obliquely. Then, a hole is drilled to the near ground surface 17 on the opposite side to form the hole 7. The injection tube 1 shown in FIG. 1 or FIG. 2 is inserted into the drilling hole 7 thus obtained, and an injection material is injected into the ground 6a to be improved to form a consolidated region 18.

  The injection tube 1 is inserted into the ground 6 as shown in FIG. 5, for example. This will be described with reference to FIG. 5. A starting pile 20 is formed on the nearby ground surface 2 and a boring machine 21 is installed. Next, a boring rod 23 provided with a drill head 22 at the tip is pushed into the ground 6 a to be improved while rotating the drill head 22 from the boring machine 21 on the nearby ground surface 19 through the starting pile 20 and drilled. At this time, the boring rod 23 is drilled while being inserted into the casing 24. When bending the drilling hole, although not shown, the drilling is continued by adjusting the tip of the drill head 22 in the bending direction. This drilling may be performed until reaching the near ground surface 19 on the opposite side, but as shown in FIG. 5, it is sufficient to perform the drilling to the end of the ground 6a to be improved.

  Injecting the injection pipe from the long columnar space by inserting the injection pipe diagonally, horizontally, or in a curved shape, and injecting the foundation ground directly under the existing building to prevent liquefaction injection, the outer pipe of the outer wall of the injection pipe Since a water permeable hole wall holding material is installed between the upper and lower adjacent bag packers having the discharge port, the injection material from the outer tube discharge port is injected into the ground from the columnar space through the holding material. The outlet is protected by a water-permeable hole wall holding material, so that the drilling wall does not collapse and the columnar space is filled, making it difficult to inject, even if the injection tube is inclined, horizontal, or Even if it is inserted in a curved line, the hole is not collapsed and the injection is satisfactorily achieved. For this reason, the present invention is highly useful for preventing liquefaction of the ground directly under an existing building.

It is sectional drawing for demonstrating the fundamental structure of the ground injection construction method and injection pipe apparatus concerning this invention. It is sectional drawing for demonstrating the injection pipe apparatus concerning this invention using a double pipe double packer, and the ground injection construction method using this injection pipe apparatus. It is a perspective view of one specific example of the water-permeable hole wall holding material used for this invention. It is a basic schematic diagram of the ground treatment to be improved directly under the structure. It is explanatory drawing showing the boring state below a structure.

Explanation of symbols

X injection pipe device 1 injection pipe 2 outer wall 3 bag packer 4 bag body 5 outer pipe discharge port 6 ground 6a ground to be improved
7 Drilling hole 8 Permeable hole wall retaining material 9 Drilling wall 10 Soil packer 11 Outer tube 12 Inner tube 13 Inner tube outlet 14 Packer 15 Rubber sleeve 16 Structure 17 Ground surface 18 Consolidation region

Claims (10)

  Boring horizontally or diagonally in the ground to be improved, or any combination of bending and straight lines, and attaching a plurality of bags to the outer wall of the injection tube at intervals in the obtained borehole, and inside the bag In addition, an injection pipe device having an outer tube discharge port opened between adjacent bag bodies is inserted, and then the curable suspension is filled into the bag body from the outer tube discharge port opened in the bag body and inflated. Forming a bag packer, and injecting an injection material from an outer tube discharge port opened between the adjacent packers to consolidate the ground, in a ground filler construction method between adjacent bag packers on the outer wall of the injection tube A ground injection construction method characterized by mounting a water-permeable hole wall holding material and injecting the injected material into the ground through the holding material through an outer tube discharge port opened between adjacent bag packers.   The ground injection method according to claim 1, wherein the water-permeable hole wall holding material is made of a woven fabric, a non-woven fabric, a water-permeable synthetic resin, a net or a drain material.   The inner tube having an inner tube discharge port in the axial direction is inserted into the injection tube, and the inner tube discharge port is surrounded by the inner tube packer and is located in a space that communicates with the outer tube discharge port. The ground injection method according to claim 1, wherein the injection material is injected into the ground from the inner tube discharge port through the outer tube discharge port and the water-permeable hole wall holding material.   The bag body according to claim 1, wherein the bag body is a water-permeable bag body that allows a part of the curable suspension to pass through, and has a diameter that is 1.2 to 5.0 times the hole diameter. The ground injection construction method according to claim 1, wherein A ≦ 2L, where L is L and A is a gap between vertically adjacent bags.   In claim 1, when the bag body is filled with a curable suspension and inflated to form a bag packer, the bag body has a diameter larger than the hole diameter, and the hole wall around the packer is consolidated by the bag packer. At the same time, the bag body is a water-permeable bag body, and a part of the curable suspension permeated from the bag body is infiltrated and consolidated into the compacted hole, so that the bag body is highly concentrated. The ground pouring method according to claim 1, wherein the ground pouring method is formed by curing to form a high-strength bag packer and forming a dense underground packer in which the pouring material hardly penetrates into the ground region around the bag packer.   An injection pipe device that is inserted into a bored hole bored horizontally or obliquely in the ground to be improved, or in any combination of bending and straight lines, and solidifies the ground, the injection pipe and the outer wall of the injection pipe A plurality of bags attached at intervals to each other, and an outer tube discharge port opened between the inside of the bag body and between adjacent bag bodies, and an outer tube discharge opening inside the bag body. The bag body is filled with a curable suspension from the outlet and inflated to form a bag packer, and the ground is consolidated by injecting an injection material from an outer tube discharge port opened between adjacent bag packers. In the injection tube device, a water-permeable hole wall holding material is attached to the outer wall of the injection tube between the bag packers, and the injection material is injected into the ground through the holding material from an outer tube discharge port opened between adjacent bag packers. An injection tube device characterized by that.   7. The injection tube device according to claim 6, wherein the water-permeable hole wall holding material is made of a woven fabric, a nonwoven fabric, a water-permeable synthetic resin, a net or a drain material.   7. The injection tube according to claim 6, wherein the injection tube includes an inner tube having an inner tube discharge port in the axial direction, the inner tube discharge port is surrounded by the inner tube packer and is located in a space communicating with the outer tube discharge port. The injection tube device according to claim 6, wherein the injection material is injected into the ground from the inner tube discharge port through the outer tube discharge port and the water-permeable hole wall holding material.   In Claim 6, The said bag body is a water-permeable bag body which permeate | transmits a part of curable suspension, Comprising: It has a diameter 1.2 to 5.0 times the hole diameter, and a bag body The infusion tube device according to claim 6, wherein A ≦ 2L, where L is L and A is a gap between adjacent bag bodies. In claim 6, when forming a bag packer by filling the bag body with a curable suspension and inflating the bag pack, the bag body has a diameter larger than the hole diameter, and the bag packer forms a hole wall around the packer. In addition to being consolidated, the bag body is a water-permeable bag body, and a part of the curable suspension permeated from the bag body is infiltrated and consolidated into the consolidated drilling wall, thereby causing the bag body to have a high concentration. 7. The injection tube device according to claim 6, wherein the injection tube apparatus is cured to form a high-strength bag packer, and a dense underground packer is formed in the ground region around the bag packer so that the injection material does not easily penetrate.

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