JP2001348868A - Ground stabilizing construction method and ground stabilizing reinforcing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a construction period and reduce a construction cost in a ground stabilizing construction method. SOLUTION: A strengthening body 10 having a hollow reinforcing member 11, a tension member 13 inserted in the reinforcing member 11, and a connecting head 12 projected from the outer surface of the reinforcing member 11 and connected to apply tensile force to the reinforcing member 11 when applying tensile force to the tension member 13, is inserted in an excavated hole H in the ground. The reinforcing member 11 is anchored to the ground by a solidifying material M filled between the excavated hole H and the outer surface of the reinforcing member, and the tension member 13 is tensed. In this tensed state, the head of the tension member 13 is anchored to a structure 3 disposed on the surface of the ground, to stabilize the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground stabilization method for stabilizing a ground having a risk of landslide using a reinforcing body, and a ground stabilizing reinforcing body used for stabilizing the ground.

[0002]

2. Description of the Related Art As a method of stabilizing a ground where a landslide may occur, a rock bolt method and an anchor method are known.

[0003] In the rock bolt method, an excavation hole is formed to reach a stable ground portion below a ground to be unstable, and a reinforcing member called a rock bolt is inserted into the excavation hole.
A solidifying material is injected between the lock bolt and the hole wall to integrate the lock bolt and the stable ground portion, and then a supporting material is installed at the position where the lock bolt is provided, and the supporting material is supported by the lock bolt. To the ground. Mainly, the ground is stabilized by the resistance of the rock bolt to the moving earth mass. Therefore, the range stabilized by one lock bolt is narrow. In addition, as shown in FIG. 8, when a force greater than the strength of the lock bolt 110 is applied, the lock bolt may be deformed as indicated by a dotted line. In the case of such deformation, the ground stabilizing effect is significantly reduced.

[0004] In one anchor method, an anchor hole is drilled at a predetermined position in the ground, a tensile steel (PC steel) is inserted into the anchor hole, and a solidifying material is injected to form an anchor body. The tip of the tension member is fixed to the ground, and then an anchor head is installed at the position where the tension member is disposed, and the tension member is tensioned using the anchor head as the head of the structure, and the structure and the ground are This is a method of reinforcing the ground by applying tensile force. In the ground where it is difficult for the anchor hole to be independent, a sheath tube may be inserted between the ground and the anchor anchoring portion. The anchoring method stabilizes the ground by pressing the structure against the ground with the anchor body as a support. The range stabilized by a single anchor is wide, but the shear and bending forces on the moving mass are very small.

[0005] The above two typical construction methods are appropriately selected according to various situations, types of ground, and the like, and in some cases, are used together to compensate for both disadvantages. In particular, in stabilizing a slope of a steep slope or the like, the rock bolt method and the anchor method are often used in combination in order to obtain a desired landslide prevention effect.

[0006]

However, when both construction methods are used in combination, dedicated equipment and tools are required for the installation of the lock bolt and the installation of the anchor body, and all of them are brought to the target ground. Must-have. For this reason, when both methods are used in combination, labor is required, construction time is long, and it is not economical.

Therefore, a main object of the present invention is to reduce the construction period and the construction cost in a ground construction method for stabilizing a ground where a landslide may occur.

[0008]

The present invention which has solved the above-mentioned problems and the effects thereof are as follows. <Invention according to claim 1> A hollow reinforcing member, a tensile member inserted into the reinforcing member, and a protrusion extending from an outer surface of the reinforcing member, the tension member acting upon the tensile member acts on the hollow member. A reinforcing body having a connecting head connected so that a tensile force acts also is inserted into an excavation hole in the ground, and the reinforcing material is injected by a solidified material injected between the excavation hole and an outer surface of the reinforcing material. While fixing the material to the ground,
A ground stabilization method, wherein the tension member is tensioned, and in this tension state, the head of the tension member is fixed to a structure disposed on the ground surface to stabilize the ground. .

(Operation and Effect of the Invention According to Claim 1) A hollow reinforcing material, a tensile material inserted inside the reinforcing material,
Since the reinforcing member has a connecting head that extends from the outer surface of the reinforcing member and is connected so that a tensile force also acts on the reinforcing member when a tension is applied to the tensile member, the reinforcing member and the tensile member are used. Need not be separately inserted into the excavation hole, so that the construction time is reduced and the construction time is shortened. Furthermore, the reinforcing material is fixed to the ground by the solidifying material injected between the excavation hole and the outer surface of the reinforcing material without injecting the solidifying material into the inside of the reinforcing material, so that the tension member can be re-tensioned. In addition, even if the number of reinforcing members is increased unnecessarily, the landslide prevention effect does not increase proportionately, but only increases the casting cost. Further, the tensile material alone is relatively weak in shear and bending force in the sliding direction and is not so effective in preventing slip. However, according to the method of the present invention, by the action of the reinforcing material and the tensile material in a tension state, the reinforcing material reinforces the tensile material that is weak against shear and bending force in the sliding direction, and also reinforces the tensile force of the tensile material. Since it is made to act on the material as well, the effect of suppressing slippage extends over a wide area. Therefore, the construction method of the present invention requires a very small number of reinforcements to be applied to the landslide prevention target ground.

<Invention according to claim 2> The ground stabilization method according to claim 1, wherein the reinforcing material is a hollow steel material whose outer surface is formed almost entirely in an irregular shape.

(Function / Effect of Invention of Claim 2) Since almost the entire outer surface of the reinforcing member is formed in an irregular shape, the friction between the outer peripheral surface of the reinforcing member and the ground is large, and the fixing force to the ground is high. .

According to a third aspect of the present invention, the connecting head has a main body and a tension member having a tapered wedge on the head side, and the wedge is provided between the outer surface of the distal end portion of the tension member and the connection head main body. The ground stabilization method according to claim 1, wherein the tension member and the connecting head are integrated.

(Operation and effect of the invention according to claim 3) Since the tension member and the connection head are connected by using a wedge without using a special connection tool, it can be easily assembled on site, Construction time is reduced.

<Invention according to claim 4> An injection pipe of a solidified material is attached along the outer surface of the reinforcing material, and simultaneously when the reinforcing material is inserted into the drilling hole, the injection pipe is also inserted into the drilling hole. The method of claim 1, wherein the solidified material is injected through the injection pipe.

(Operation and effect of the invention according to claim 4) An injection pipe of a solidified material is attached along the reinforcing body, and simultaneously when the reinforcing body is inserted into the drilling hole, the injection pipe is inserted into the drilling hole. Therefore, there is no need to separately inject the injection pipe, and the construction time can be shortened.

<Invention according to claim 5> The ground stabilization method according to claim 1, wherein the reinforcing body is inserted into the stable ground portion which is deeper than the unstable ground portion.

(Function / Effect of the Invention of Claim 5) In addition to the effect of claim 1, in the case of a ground having a stable ground portion below the unstable ground portion, the unstable ground portion may be a structure. And the stable ground portion can be compacted and stabilized.

<Invention according to claim 6> A hollow reinforcing material,
A tension member inserted into the inside of the reinforcing member, and a connection head projecting from an outer surface of the reinforcing agent and connected so that a tensile force acts on the reinforcing member when a tension is applied to the tension member. Wherein the reinforcing material is a hollow steel material whose outer surface is formed almost entirely in an irregular shape.

(Function / Effect of the Invention of Claim 6) The reinforcing body of the present invention comprises a hollow reinforcing material, a tensile material inserted inside the reinforcing material, and an overhanging outer surface of the reinforcing agent. Since the connecting head is connected so that a tensile force acts on the reinforcing member when a tension is applied to the member, the reinforcing member and the tensile member can be simultaneously inserted into the excavation hole. . The construction time per reinforcing body is the same as the ordinary anchoring method or rock bolt method, but the composite ground stabilization by the tensile material and the reinforcing material is possible. Further, since the tension member passes through the inside of the hollow reinforcement, the tension member protects the tension member from the hole wall. In addition, since almost the entire outer surface of the reinforcing member is formed in an irregular shape, a high anchoring effect is achieved when the reinforcing member is fixed to the ground.

<Invention of Claim 7> The connecting head has a main body and a wedge having a tapered wedge on the head side of the tension member, and the wedge is provided between the outer surface of the tip end of the tension member and the connection head main body. 7. The tension member and the connecting head are integrated.
The reinforcing body for ground stabilization according to the above.

(Operation / Effect of the Invention of Claim 7) Since the tension member and the connection head are connected by using a wedge, they can be easily assembled on site without using special connection tools. Excellent workability.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an example of the reinforcing body of the present invention. The reinforcing member 10 includes a hollow reinforcing member 11 and a reinforcing member 1.
1 and a connecting head 12A which protrudes from the outer surface of the reinforcing material and is connected so that a tensile force acts on the reinforcing material when a tension is applied to the tensile material. It is configured.

The reinforcing member 11 has a length of about 3 to 7 m,
A rigid steel pipe or a hollow lock bolt having an outer diameter of about 30 to 50 mmφ and an inner diameter of about 15 to 40 mmφ is suitable.
Further, as shown in the drawing, it is more preferable that the outer surface of the reinforcing member is formed in an irregular shape, since the fixing force to the ground is increased.

On the other hand, the tensile member 13 is preferably a PC steel material, a PC steel stranded wire, or the like. In addition, a known tensile material used for ground stabilization can be used.

On the other hand, FIG. 2 shows details of the connection head. The connection head 12A includes a support member 12s, a wedge 12w having a tapered head portion of the tension member 13, and a tip cap 12p. When the wedge 12w is inserted between the support member and the tension member while the tension member 13 is passed through the insertion hole 12h formed at the center of the support member 12s, the tension member 13 is fixed to the connection head. A distal end cap 12p is provided at the joint between the support member 12s and the wedge 12w so as to cover this portion. The distal end cap protects the fixed portion from erosion such as rainwater and the like, and the fixed state is good. Is held. In the illustrated example, the fixing portion is covered by screwing a screw portion 12n provided on each of the support member 12s and the tip cap 12p. Alternatively, the tip cap and the support material may be welded.

Here, another example of the reinforcing member according to the present invention is shown in FIGS. The reinforcing body shown in FIG. 3 is an example in which a crimping grip 12B is used as a connecting head. The illustrated grip is cylindrical and attached to a portion of the tension member that extends beyond the tip of the reinforcement. The crimping grip is attached to the tension member by applying pressure from the outside of the crimping grip with the tension member inserted into the inner hole. On the other hand, the reinforcing member shown in FIG. 4 is an example in which a block member 12C projecting from the outer surface of the reinforcing member is used as a connecting head. The block material is
The tension member is welded and attached to a portion extending from the tip of the reinforcing member.

Each of the connecting heads shown in the above examples projects from the outer surface of the reinforcing member, transmits the tensile force of the tensile member to the reinforcing member, and seals the opening at the front end of the reinforcing member to form the reinforcing member 10. Is prevented from entering the inside of the reinforcing member 11.

Here, the connecting head may be fixed to a tip of the reinforcing member. The fixing method is not particularly limited, but as a preferred example, a female screw portion is provided on the support member, and a male screw portion is provided on the outer periphery of the distal end portion of the reinforcing member, and these are screwed together. Further, the connection head can be fixed even by welding to the reinforcing material.

Further, the material of the connecting head 12 is not limited.
It is necessary to be made of a material having a strength not to be damaged and to be a material through which the solidified material does not penetrate so that the solidified material does not enter the inside of the reinforcing material.

<First Working Example> Next, a working example of the present invention will be described in more detail with reference to the drawings. 5 to 7 show construction examples of the ground stabilization method of the present invention. As shown in the figure, in the target ground, a stable ground portion 1B exists below the unstable ground portion 1A, and a boundary between the stable ground portion 1B and the virtual landslide line 2 is formed. The structure 3 is constructed on the surface of the unstable ground portion 1A. In the case of a slope or a slope, the structure 3 is a cast-in-place concrete or a mortar spray-filled frame.

First, an excavation hole H is formed on the target ground so as to reach the stable ground portion 1B deeper than the virtual landslide line 2. The drilling hole H is drilled using a drilling rod, a double pipe rod, or the like, based on the conventional technology.
After the excavation hole H is formed, the above-described reinforcing body 10 of the present invention is inserted into the excavation hole H. If you use a double tube,
The reinforcing body 10 is inserted into the casing tube, and the casing tube is pulled out after the insertion or after the solidification material is injected.

In the reinforcing member 10, a tension member 13 passes through a hollow reinforcement member 11, and the reinforcement member 11 and the tension member 13 are integrated by a connecting head 12A attached to the tip of the reinforcement member 11. ing. In the example shown,
A hollow lock bolt is used as the reinforcing member 11, and a PC steel wire is used as the tensile member 13.

After the reinforcing member 10 is inserted into the drill hole H, the solidified material M is injected into the drill hole H, and the reinforcing member 1
0 is fixed to the target ground. At this time, reinforcing material 1
1 is not fixed to the structure 3. By not fixing the reinforcing member 11 to the structure 3, the tensile force of the tension member 13 can be transmitted to the structure 3.

Here, in the present invention, it is not always necessary to inject the solidified material M after the insertion of the reinforcing member 10, and the solidified material may be injected into the excavation hole H prior to the insertion of the reinforcing member 10. Good. Further, as the solidified material M according to the present invention, it is possible to use a known solidified material, such as cement milk, which is used in a conventional anchor method or rock bolt method.

The solidified material M can be injected using an injection pipe in the same manner as in the conventional anchoring method (the injection pipe is not shown). At this time, the sheath tube 1 is inserted between the structure 3 and the reinforcing material 11 so that the reinforcing material 11 is not fixed to the structure 3.
4 is preferably provided. The method of inserting the injection tube, the position of the discharge port after insertion is not particularly limited,
As a preferred example, an injection pipe is attached along the reinforcing body 10 in advance, and when the reinforcing body is inserted into the drill hole H, the injection pipe is inserted at the same time. By doing so, the labor for separately inserting the injection tube can be omitted. Further, it is preferable that the discharge port of the injection pipe is located near the connection head 12. When the solidified material M is discharged near the connecting head 12, the connecting head 12 is reliably fixed to the stable ground portion 1B. Further, the sheath tube 14 may be used as an injection tube. Also,
The injection tube may be buried after injection of the injection material. Reinforcing material 1
When 1 is fixed on the ground, the reinforcing material 11 exerts shear resistance and bending resistance in the unstable ground portion 1A, and resists the moving soil mass.

When the reinforcing member 11 has settled on the ground, a tensioning device such as a jack (not shown) is installed on the structure 3, and the head of the tension member 13 is pulled by using the structure 3 as a support. Tension 13 When the tension member 13 is tensioned, the tension member 13 is moved to the structure 3 in this tension state.
Fix so that tension is transmitted to A method of fixing the tension member 13 so that the tension is transmitted to the structure can be performed based on a conventional anchoring method. For example, as shown in the figure, the tension member 13 in a tensioned state is connected to the structure 3.
Anchor head 1 on fixing plate 15 mounted thereon
6 is fixed by a fixing wedge 17.

Here, in the method of the present invention, a rust preventive or the like may be injected into the reinforcing member 11 before the tension member 13 is tensioned. In addition, the reinforcing material 11
A cover 18 may be provided on the head of the reinforcing member 11 so that rainwater, earth and sand, etc. do not enter the inside. Although the cover member 18 may be in contact with the fixing plate 15 as shown in the figure, in this case, the function of the fixing plate 15 pressing the structure 3 when the tension member 13 is tensioned is not hindered. As described above, for example, it is preferable to be formed of flexible rubber or the like.

When the tension member 13 is fixed to the structure 3 in a tension state, the tension 3 of the tension member 13 is transmitted to the structure 3, and the structure 3 is pressed against the ground, and the unstable ground portion 1A Is compacted between the structure 3 and the stable ground portion 1B, and the frictional resistance at the virtual landslide line 2 increases.

<Second Construction Example> If the drilling holes can be made independent on the target ground, a plurality of drilling holes are first formed in the target ground, and the drilling of the drilling holes is performed before the solidification material is injected. A reinforcing material may be built in the hole, and then the solidifying material may be sequentially injected into the excavation hole in which the reinforcing material has been built.

<Others> Thus, when the reinforcing member is driven into the target ground, as shown in FIG. 7, even if an excessive force is applied to the reinforcing member 11 by the moving soil mass, the tensile member passing through the reinforcing member 11 13, the reinforcing body 10 is deformed as shown by a dotted line in FIG.
Exerts shear resistance and bending resistance on the moving soil mass.

[0041]

As described above in detail, according to the present invention, in a method for stabilizing a ground which may cause a landslide,
The construction period is shortened and the construction cost is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first example of a reinforcing member according to the present invention.

FIG. 2 is a view showing a connection head according to the present invention.

FIG. 3 is a cross-sectional view showing a second example of the reinforcing member according to the present invention.

FIG. 4 is a cross-sectional view showing a third example of a reinforcing body according to the present invention.

FIG. 5 is a diagram showing a state in which a reinforcing body is cast on a target ground.

FIG. 6 is an enlarged view of the vicinity of the head of the reinforcement.

FIG. 7 is a view showing a ground stabilization method of the present invention.

FIG. 8 is a view showing a conventional lock bolt method.

[Explanation of symbols]

1A: Unstable ground portion, 1B: Stable ground portion, 2: Virtual landslide line, 3: Structure, 10: Reinforcement, 11: Reinforcement, 1
2A, 12B, 12C: connecting head, 12s: supporting material,
12w: wedge, 12p: tip cap, 13: tension material,
14: sheath tube, 15: fixing plate, 16: anchor head, 17: fixing wedge, 18: lid material, H: drilling hole, M:
Solidification material, 110: lock bolt, 116: supporting body.

Claims (7)

[Claims] 1. A hollow reinforcing member, a tensile member inserted into the reinforcing member, and a projection extending from an outer surface of the reinforcing member, the tension member also tensions the reinforcing member when a tension is applied to the tensile member. A reinforcing body having a connection head connected so that a force acts thereon is inserted into an excavation hole of the ground, and the reinforcing material is ground by a solidified material injected between the excavation hole and an outer surface of the reinforcement. In addition, the tension member is tensioned to fix the head of the tension member to a structure disposed on the ground surface in this tension state, thereby stabilizing the ground. Ground stabilization method. 2. The ground stabilization method according to claim 1, wherein the reinforcing material is a hollow steel material whose outer surface is formed almost entirely in an irregular shape. 3. A connecting head having a main body and a wedge tapered on the head side of the tension member, the wedge being provided between an outer surface of a leading end portion of the tension member and the connecting head main body, The ground stabilization method according to claim 1, wherein the ground stabilization method is integrated. 4. A solidification material injection pipe is attached along the outer surface of the reinforcing material, and when the reinforcing material is inserted into the drilling hole, the injection pipe is also inserted into the drilling hole, and the solidification material is inserted through the injection pipe. The method of reinforcing a ground according to claim 1, wherein the ground is injected. 5. The ground stabilization method according to claim 1, wherein the reinforcing body is inserted into the stable ground portion which is deeper than the unstable ground portion. 6. A hollow reinforcing member, a tensile member inserted into the reinforcing member, and a projection extending from an outer surface of the reinforcing member, the tension member also tensions the reinforcing member when a tension is applied to the tensile member. A ground stabilizing reinforcing body, comprising: a connecting head connected so as to apply a force; and the reinforcing member is a hollow steel material whose outer surface is substantially entirely formed in an irregular shape. 7. A connecting head having a main body and a wedge tapered on the head side of a tension member, the wedge being provided between an outer surface of a leading end portion of the tension member and the connection head main body, wherein the tension member and the coupling head are provided. The reinforcing body for ground stabilization according to claim 6, wherein is integrated.