JP5696687B2 - Ground reinforcement structure construction method - Google Patents

Description

The present invention relates to a method for the construction of the ground reinforcement structure.

  Conventionally, in order to prevent subsidence of soft ground and collapse of slopes, a ground reinforcement method for improving the ground by stabilizing the ground has been performed. For example, a method as disclosed in Patent Document 1 or 2 Has been proposed.

  In Patent Document 1, a reinforcing material such as a steel rod is inserted into a hole drilled by boring, and mortar or grout cement is injected into the gap between the hole inner surface and the reinforcing material to integrate the reinforcing material and the ground. Thus, a so-called nailing method for constructing a ground reinforcing structure is disclosed.

  Further, in Patent Document 2, a soil cement column is built in the ground by continuing stirring and mixing while pouring cement milk through the hollow shaft of the stirrer into the ground stirred by a specially shaped kneading auger. A soil cement construction method is disclosed in which a ground reinforcing structure is constructed by inserting and installing a core material in the hollow portion of the hollow shaft on the ground at the end of the excavated and stirred earth and sand range.

JP 2004-27813 A JP-A-5-222733

  By the way, when a bending load acts on the ground reinforcing structure to cause warping, a tensile force is generated on the convex side of the warp of the ground reinforcing structure, and a compressive force is generated on the concave side of the warp.

  However, in the ground reinforcement method disclosed in Patent Document 1 or 2, the steel rod or core material installed to resist the tensile force has a cross section with a small tensile force generated when a bending load is applied to the ground reinforcing structure. Located in the centroid. For this reason, there exists a problem that the tensile strength which a steel rod and a core material cannot fully exhibit.

  In addition, the ground that is likely to be displaced in the vertically downward direction, such as the upper ground of a tunnel with a shallow earth covering shown in FIG. 8A and the soft ground under the structure shown in FIG. In the case of reinforcing the ground 70), it is effective to construct the ground reinforcing structure 40 horizontally on the ground to be reinforced 70 as shown in FIG.

  However, in the ground reinforcement method disclosed in Patent Document 1 or 2, since the ground reinforcement structure 40 to be constructed is limited to a linear shape, when constructing from the ground surface, for example, as shown in FIG. In addition, the ground reinforcement structure 40 can only be placed diagonally from both sides with respect to the reinforcement target ground 70 (FIG. 1 (a)), or directly above and vertically downward (FIG. 1 (b)). In this case, in order to suppress the vertical downward displacement of the ground, it is necessary to construct a larger number of ground reinforcing structures 40 than in the horizontal construction, which requires construction cost and construction time. As shown in FIG. 10, it is conceivable to form a shaft 80 at a position adjacent to the ground to be reinforced 70, and to construct the ground reinforcing structure 40 from the shaft 80 in the horizontal direction. In addition to the construction cost and time required for forming the shaft, it is necessary to secure a site for constructing the shaft 80.

The present invention has been made in view of the above points, and has a simple configuration, can sufficiently resist bending load from the ground, and can be constructed in a bent or curved shape. and to provide a construction method for soil reinforcement structure structure.

In order to achieve the above object, a method for constructing a ground reinforcement structure , wherein one end opens to the ground surface while the other end closes in the ground while pouring muddy water into the ground, and the one end side A bag formed by forming a hole having a bent shape that changes the direction from the obliquely downward direction to the horizontal direction toward the other end side, having flexibility and closing one end of a cylindrical body having a predetermined tensile strength. In the hole formed in the ground, the one end where the bag body is closed is placed so as to be located on the other end side where the hole is closed, and solidifies in the bag body over time. While filling the filler in the fluid state from the one end side of the bag body closed toward the other end side, the bag body is expanded by the filling of the filler material, so that the muddy water is discharged from the opening of the hole. To discharge and solidify this filler And butterflies.
Further, the present invention is a construction method of a ground reinforcement structure, in which muddy water is poured into the ground, holes are formed so that both ends open to the ground surface, and has flexibility and a predetermined tensile strength. A bag formed by closing one end of a cylinder is installed in a hole formed in the ground, and the bag is closed in a fluidized state with a filler that solidifies with time. From the opening on the one end side of the bag body, the muddy water is expanded by filling the filler while filling from the other end side to the one end side closed from the other end side. It is characterized by discharging and solidifying this filler.

According to the present invention, provides a simple structure, a filler for filling the hole formed in the ground, the solidified allowed by ground reinforcing structure construction method capable of constructing without escape into the surrounding ground it can.

The ground reinforcement member which concerns on this embodiment is shown, The figure (a) is a side view, The figure (b) is AA sectional drawing of (a). It is explanatory drawing for demonstrating the procedure of the 1st construction method which builds a ground reinforcement structure using a ground reinforcement member. It is explanatory drawing for demonstrating the installation method by the air pressure insertion of a ground reinforcement member. It is explanatory drawing for demonstrating the procedure of the 2nd construction method which builds a ground reinforcement structure using a ground reinforcement member. It is explanatory drawing for demonstrating the method of filling the filler 26 in the ground reinforcement member 10, discharging the muddy water 27 in a hole outside, The figure (a) is the ground reinforcement member installed in the bending hole 22. FIG. 10B shows a case where the ground reinforcing member 10 installed in the bent through hole 30 is filled. The installation example of the ground reinforcement structure on the upper ground of the tunnel or shield crossing perpendicularly to the railway track is shown, (a) is a plan view, (b) is a cross-sectional view, and (c) is a longitudinal section. FIG. The example of installation of the ground reinforcement structure to the upper ground of the tunnel or shield crossing obliquely with the railroad track is shown, and the same figure (a) is a plan view and the same figure (b) is a cross-sectional view. It is sectional drawing which shows the effective construction arrangement of the ground reinforcement structure for reinforcing the ground which is easy to produce the displacement of the vertical downward direction. The figure (a) is the case of the shallow tunnel, and the figure (b) This is the case for soft ground under the structure. It is sectional drawing which shows the construction arrangement of the ground reinforcement structure for reinforcing the ground which tends to generate the vertical downward displacement by the conventional construction method, and the figure (a) is a diagonal view of the ground reinforcement structure from both sides with respect to the ground to be reinforced. The construction cross section laid in the direction, FIG. 5 (b) shows the construction cross section in which the ground reinforcement structure is placed in the vertical downward direction from directly above the ground to be reinforced. It is sectional drawing for demonstrating the procedure which builds a ground reinforcement structure in the horizontal direction by the conventional construction method.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.
1A and 1B show a ground reinforcing member according to the present embodiment, in which FIG. 1A is a side view and FIG. 1B is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 1, the ground reinforcing member 10 is, for example, an elongated bag body in which a distal end portion 10a of a flexible cylindrical member is closed, and an injection port 16 is formed at the base end portion 10b. ing. The ground reinforcing member 10 is installed in a hole cut in a bent shape in the ground as will be described later with the inside of the bag body empty, and then filled with concrete milk or the like from the inlet 16 into the bag body. A ground reinforcement structure is constructed by filling and solidifying the material.

  As a constituent material of the bag body, for example, a reinforcing cord 14 having a high tensile strength such as aramid yarn or carbon fiber is mixed into a woven fabric or a nonwoven fabric made of hemp or synthetic fiber having flexibility and wear resistance. Or a structure in which a plurality of reinforcing cords 14 are provided along the longitudinal direction around the ground reinforcing member 10 can be used. In the latter case, in order to evenly resist the bending load regardless of the direction from which direction the bending load is applied to the ground reinforcing structure constructed using the ground reinforcing member 10, FIG. As shown, the reinforcing cords 14 are preferably provided at equal intervals around the bag.

  The ground reinforcing member 10 is required to have a strength that can withstand the pressure (for example, 0.1 to 1 Mpa) of the filler injected into the ground reinforcing member 10. This is, for example, as strong as a fire hose.

  In addition, the ground reinforcing member 10 is preferably made of a woven fabric or a nonwoven fabric having such a roughness that only the moisture contained in the filler filled therein is leached into the ground outside the bag body. In addition, you may use the water-impermeable film | membrane provided with the fine hole not only the said woven fabric or a nonwoven fabric.

  Furthermore, it is preferable that the ground reinforcing member 10 can be expanded and contracted so that the bag body expands to some extent so that the ground reinforcing member 10 is in close contact with the hole wall when the inside thereof is filled with a filler.

  Further, as the ground reinforcing member 10, a member having a tensile strength that can sufficiently resist the tensile force generated in the ground reinforcing structure due to a bending load or the like when it becomes a part of the ground reinforcing structure is used. In addition, a filler having a compressive strength that can sufficiently resist the compressive force generated in the ground reinforcing structure due to a bending load or the like when it becomes a part of the ground reinforcing structure is used.

Next, a procedure for constructing a ground reinforcement structure in order to reinforce a foundation under the embankment 20 constructed on a soft ground, for example, using such a ground reinforcement member 10 will be described.
FIG. 2 is an explanatory diagram for explaining the procedure of the first construction method for constructing the ground reinforcing structure using the ground reinforcing member 10.

  As shown in FIG. 2, the first construction method includes a bending hole drilling step S110, a ground reinforcing member installation step S120, and a filler filling step S130.

  In the drilling step S110 of the bent hole, drilling is started obliquely from the surface position adjacent to the embankment 20 constructed on the ground surface toward the foundation ground below the embankment 20 to be reinforced, and the tip of the hole is embankment. When reaching the lower position of the edge of 20, the drilling direction is changed to the horizontal direction (step S111), and then a bent hole (bent hole 22) having a horizontal portion of a predetermined length is drilled. (Step S112).

  In the drilling step S110 of the bent hole, a known induction-type universal boring machine capable of freely changing the drilling direction in the ground (for example, a drilling machine using a terra-jet method or an urban nodic method) Can be used. In addition, after drilling the bending hole 22, the drill bit 21 and the boring rod 23 of the boring machine used for drilling are pulled out and collected.

  In the ground reinforcing member installation step S120, a guide rod 24, such as a metal wire, which is bendable and elastic, is inserted into the inside of the base end portion of the bag body of the ground reinforcing member 10 (step S121). Then, the bag body is inserted into the bent hole 22 by pushing the closed end portion 10a to the tip of the bent hole 22 drilled in step S110 (step S122). Here, when the ground reinforcing member 10 is inserted into the bending hole 22 using the guide rod 24, for example, a protective member such as a cushion is attached to the guide rod so that the tip of the guide rod 24 does not damage the ground reinforcing member 10. Take measures such as providing it at the tip of 24. In addition, after installation of the ground reinforcement member 10, the guide rod 24 is pulled out from the hole and collected.

  In the filling material filling step S130, the ground reinforcing structure 40 is constructed by filling and solidifying the inside of the ground reinforcing member 10 installed in the bent hole 22 in the step S120. The filler 26 is filled through the inlet 16 described above. In addition, in order to improve the tensile strength of the concrete after solidification, it is preferable to use a filler mixed with a reinforcing fiber material such as steel fiber or glass fiber.

  When injecting the filler 26, pressurization is performed until the injection pressure becomes about 0.1 to 1 MPa. Then, the injection port 16 is sealed so that the internal pressure is maintained after the injection is completed. Thereby, the water in the filler 26 filled in the ground reinforcing member 10 is squeezed and leached into the ground, and a certain amount of the solidified component of the filler 26 in the ground reinforcing member 10 is concentrated and solidified. Thus, the ground reinforcement structure 40 is constructed.

  For example, when the injection hose is placed along the guide rod 24 and the step S120 is performed, the injection hose is inserted together with the guide rod 24 from the base end portion 10b of the ground reinforcement member 10, and the ground reinforcement member 10 is attached. The bag may be filled with a filling material via an injection hose while the guide rod 24 is pulled out from the hole and then pushed to the tip of the bent hole 22.

  Thereby, the installation process S120 of the ground reinforcing member and the filling process S130 of the filler can be performed simultaneously. In addition, since the filling material is filled into the bag body from the distal end portion 10a of the bent hole 22, the air in the bag body can be smoothly sent from the distal end portion 10a to the proximal end portion 10b when not filled. The ground reinforcement structure 40 having a highly reliable rigidity can be constructed by avoiding air remaining in the body.

  About the installation process S120 of the ground reinforcement member demonstrated above, you may use the installation method by pneumatic insertion as shown in FIG.

  As shown in FIG. 3, in the installation method by air pressure insertion, for example, the ground reinforcing member 10 is folded in the vicinity of the hole of the bent hole 22 in a bellows shape, and the tip 10a is installed from the hole toward the inside of the hole. The ground reinforcing member 10 is inserted into the bottom of the hole by injecting air from the inlet 16 into the interior of the container (step S123), thereby applying a propulsive force to the bag body or expanding the bag body (step S124).

  In carrying out the installation method by air pressure insertion, when the ground reinforcing member 10 is inserted into the hole, an air vent hose 28 for releasing the air in the hole forward from the ground reinforcing member 10 into the atmosphere is provided at the tip thereof. It is preferable to install in advance to reach the vicinity of the hole tip. Thereby, the ground reinforcement member 10 can be smoothly inserted into the hole bottom.

  Moreover, in the installation method by air pressure insertion, you may press-fit the filler 26 instead of press-fitting air in the ground reinforcement member 10. FIG. Thereby, the installation step S120 of the ground reinforcing member and the filling step S130 (see FIG. 2) of the filler can be performed simultaneously.

  FIG. 4 is an explanatory diagram for explaining the procedure of the second construction method for constructing the ground reinforcing structure using the ground reinforcing member 10. In FIG. 4, the same reference numerals are given to the same parts as those in FIG. 2, and the description thereof is omitted.

  As shown in FIG. 4, the second construction method includes a bending through hole drilling step S210, a ground reinforcing member installation step S220, and a filler filling step S230.

  In the bent through hole drilling step S210, in the same manner as in the bent hole drilling step S110 described with reference to FIG. 2, a bent hole having a horizontal portion of a predetermined length is drilled (step S211), and further toward the ground surface. Then, the bent through hole 30 that has been drilled to the ground surface by changing the drilling direction is drilled (step S212).

  The bent through hole 30 is also drilled using the same induction type boring machine as in the first construction method.

  In the ground reinforcing member installation step S220, the base end portion of the ground reinforcing member 10 is disposed in the vicinity of the distal end portion of the boring rod 23 of the induction-type universal boring machine used when penetrating the ground between both sides of the embankment 20 in the previous step S210. The ground reinforcing member 10 is pulled into the bent through hole 30 by attaching 10 b and pulling out the boring rod 23.

  Further, in the same figure, the ground reinforcing member 10 is arranged in a part of the region of the bent through hole 30 (the central horizontal portion and the inclined portion on the right side in the drawing as in the first method), but this is not the only case. Instead, it may be installed in the entire region of the bent through hole 30 that has been drilled. Here, when arranging in a part of the area of the bent through hole 30 as in the former, it is preferable to backfill the hole portion 30c where the ground reinforcing member 10 is not installed with concrete or earth and sand.

  The filler filling step S230 performed in the second method is the same as the filler filling step S130 in the first method.

  The first and second construction methods described above are carried out when the drilled hole (the bent hole 22 or the bent through hole 30) is self-supporting without collapsing, or when a casing can be installed in the hole.

  On the other hand, when the hole drilled in the ground cannot be self-supported and collapses or it is difficult to install a casing, the hole wall is protected in the hole during drilling (step S110 or step S210). Drilling while injecting muddy water (for example, bentonite) to prevent collapse. Moreover, in installation of the ground reinforcement member 10 (process S120 or process S220), the ground reinforcement member 10 is inserted into the hole filled with muddy water. Here, since the specific gravity of the muddy water is large, the pushing by the guide rod 24 (step S121 and step S122) and the drawing by the boring rod 23 (step S221 and step S222) are more than the press-fitting by air (step S123 and step S124). Can be inserted more easily. Furthermore, if the bag is deflated, it is easy to insert smoothly.

  In filling the filler (step S130 or step S230), it is necessary to discharge the muddy water in the hole to fill the ground reinforcing member 10 with the filler.

  FIG. 5 is an explanatory view for explaining a method of filling the ground reinforcing member 10 with the filler 26 while discharging the muddy water 27 in the hole to the outside. FIG. 5A is installed in the bent hole 22. In the case where the ground reinforcing member 10 is filled, FIG. 4B shows the case where the ground reinforcing member 10 installed in the bent through hole 30 is filled.

  In the case of the bent hole 22, as shown in FIG. 5 (a), the injection hose 25 previously described in step S120 is inserted along the guide rod 24 to the distal end portion 10a of the bag body, and the ground reinforcing member 10 is inserted. It is preferable to fill the filler 26 through the injection hose 25 from the distal end portion 10a while pulling out the guide rod 24. As a result, as the filling material 26 is filled into the bag body, the muddy water 27 is pushed out from the tip of the bent hole 22 to the hole and discharged.

  On the other hand, in the case of the bent through hole 30, as shown in FIG. 5B, the muddy water 27 can be discharged from the hole of the bent through hole 30 on the distal end portion 10a side, so that it is the base end portion 10b of the bag body. A filler may be injected from the injection port 16.

  According to the ground reinforcing structure 40 of the present embodiment described above, a woven fabric or a nonwoven fabric in which the reinforcing cords 14 are mixed as a constituent material or a plurality of reinforcing cords 14 are provided along the longitudinal direction is used. Thus, the tensile strength of the bag can be increased. Thereby, in the cross section of the ground reinforcing structure 40 constructed by using this bag body, the solidified filler 26 is arranged at the center, and the bag body whose tensile strength is increased is arranged around it. That is, since the reinforcing rope 14 is arranged at the position farthest from the center of the cross section of the bag body, the reinforcing rope 14 against the tensile force generated when a bending load is applied to the ground reinforcing structure 40. Resists effectively. Moreover, the solidified filler can resist the compressive stress caused by the bending load.

  Further, according to the ground reinforcing structure 40 of the present embodiment, by using a woven fabric or a non-woven fabric as a constituent material of the ground reinforcing member 10, the filler 26 filled in the ground reinforcing member 10 in a fluidized state is a woven fabric or a non-woven fabric. When it is infiltrated into the mesh and then solidified, it becomes integral with the cylinder or bag, so that it can be a rigid body that resists both tensile and compressive forces.

  Moreover, according to the ground reinforcement structure 40 of this embodiment, since the bag body which comprises the ground reinforcement member 10 has a softness | flexibility, a bag body is put in the hole of the bending hole 22 or the bending through-hole 30 which has a horizontal part. It is possible to install by pushing the guide rod 24 or blowing air into the ground reinforcing member 10 and then filling the inside of the bag body with the filler 26 and solidifying it. It is possible to construct a bending-shaped reinforcing structure having

  Further, the ground reinforcing member 10 uses an aramid yarn as the reinforcing rope body 14 that resists the tensile force, so that, for example, when a pile is hit on the ground reinforced by the ground reinforcing structure 40, a ground reinforcing structure is used by a pile driving machine or the like. 40 can be overcome without problems. That is, when a metal member such as a steel bar or a core material is used as the ground reinforcing structure as in the construction method described in Patent Document 1 or 2, the steel bar is punched when the ground reinforcing structure 40 is punched. However, the ground reinforcement structure 40 of the present embodiment does not cause such a problem that the core material is entangled with the pile.

  Moreover, the ground reinforcement structure 40 uses the thing which mixed reinforcement fiber materials, such as steel fiber and glass fiber which have tensile strength, with the filler 26 with which the ground reinforcement member 10 is filled, The ground reinforcement structure 40 is used. The tensile strength of can be further improved.

  In addition, since the ground reinforcing structure 40 can be provided with a shape extending in the horizontal direction directly below the embankment 20, it effectively resists the bending load in the vertical direction and suppresses the vertical displacement of the soft ground under the embankment 20. can do. Here, in order for the ground reinforcing structure 40 to sufficiently resist the bending load in the vertical direction, it is necessary that no slip occurs between the ground reinforcing structure 40 and the ground. It is preferable that the construction is performed so that the length is sufficient on both sides immediately below the range where the embankment 20 is provided.

  In addition, although the ground reinforcement member 10 of this embodiment is a bag-shaped thing with which the front-end | tip part 10a was obstruct | occluded, not only this but the cylinder body which the front-end | tip part 10a opened may be sufficient. In this case, the installation method using the air pressure cannot be applied to the bending hole 22, so the guide rod 24 is used for installation.

  In addition, the ground reinforcing member 10 of the present embodiment is a woven or non-woven fabric having a fineness such that only moisture outflows into the ground outside the bag body, or a fine one of the fillers 26 filled therein. Although the water-impermeable film provided with holes is used, the present invention is not limited to this, and a bag body from which moisture does not leach may be used. In this case, hydraulic concrete or the like that can be solidified while containing moisture is used as the filler 26.

  Moreover, in this embodiment, although the example which reinforces the soft ground under the embankment 20 using the ground reinforcement member 10 was shown, the tunnel of a shallow earth covering passing directly under a railroad track, a road, etc., or a shield Applicable for reinforcement.

  FIG. 6 shows an installation example of a ground reinforcement structure on the upper ground of a tunnel or shield that crosses at right angles to the railroad track. FIG. 6 (a) is a plan view, FIG. 6 (b) is a cross-sectional view, FIG. c) is a longitudinal sectional view.

  As shown in FIG. 6, the ground reinforcing structure 40 is disposed on the ground between the embankment 20 and the tunnel or shield 50 in the same direction as the extending direction of the tunnel or shield 50 and horizontally by the ground reinforcing method described above. (Refer to (c) in the figure), a plurality of structures are constructed around the tunnel or shield 50 (see (a) and (b) in the same figure).

  FIG. 7 shows an example of the ground reinforcement structure installed on the upper ground of the tunnel or shield crossing obliquely with the railway track. FIG. 7 (a) is a plan view and FIG. 7 (b) is a cross-sectional view. is there.

  As shown in FIG. 7, the ground reinforcing structure 40 is arranged in a direction orthogonal to the extending direction of the tunnel or shield 50 unlike the case of FIG. 6 described above (see FIG. 7A and FIG. 7B). The tunnel or shield 50 is constructed in a plurality of extending directions (see FIG. 5A).

  Compared with the case where the tunnel or shield 50 of FIG. 6 is orthogonal to the railroad track, the tunnel or shield 50 is obliquely crossed with the railroad track in FIG. If it is going to construct the ground reinforcement structure 40 with the same arrangement | positioning, the drilling of a long distance bending hole and installation of the ground reinforcement member 10 to the bending hole will be needed, and construction cost and construction time will be needed. This is because of this.

  In addition, the ground reinforcing member 10 of the present embodiment is used to reinforce the bent-shaped ground reinforcing structure 40, but is not limited thereto, and may be used to reinforce a linear ground reinforcing structure. Needless to say.

DESCRIPTION OF SYMBOLS 10 Ground reinforcement member 14 Reinforcement cord body 16 Inlet 20 Filling 22 Bending hole 23 Boring rod 24 Guide rod 25 Injection hose 26 Filling material 27 Muddy water 28 Bleeding hose 30 Bending through-hole 40 Ground reinforcement structure 50 Tunnel or shield 70 Ground to be reinforced 80 Vertical shaft 10a Tip 10b Base end S110 Bending hole drilling process S120 Ground reinforcement member installation process S130 Filling material filling process S210 Bent through hole drilling process S220 Ground reinforcement member installation process S230 Filling material filling process

Claims (2)

It is a construction method of ground reinforcement structure,
Bending to change the direction from the diagonally downward direction to the horizontal direction from one end side to the other end side while injecting muddy water into the ground so that one end is open to the ground surface and the other end is closed in the ground Forming a hole having a shape ;
A bag body that has flexibility and has a predetermined tensile strength and is closed in a hole formed in the ground. The closed end of the bag body is closed in the hole. Install so that it is located on the other end side,
The bag body is filled with the filler while filling the inside of the bag body from the one end side to the other end side where the bag body is closed in a fluidized state with a filler that solidifies over time. The construction method of the ground reinforcement structure characterized by discharging the muddy water from the opening of the hole by expanding and solidifying the filler. It is a construction method of ground reinforcement structure,
While injecting muddy water into the ground, form holes so that both ends open to the ground surface ,
A bag body formed by closing one end of a cylindrical body having flexibility and a predetermined tensile strength is installed in a hole formed in the ground,
Inside the front Symbol bag, with the filler fluid state which solidifies over time, while filling toward the one end side which is closed from the other end which is not closed in the bag, the filling material the mud and the holes, and discharged from the one end side of the opening of the bag, the construction method of soil reinforcement structure, characterized by solidifying the filler by previous SL bag body is expanded by filling.