JP2811038B2 - Large-diameter bending tensile reinforcement and its construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground reinforcement technique for steepening a gentle slope or stabilizing a cut slope, and more particularly, to a large-diameter bending for the purpose of ground reinforcement. The present invention relates to a tensile reinforcement (hereinafter referred to as a “reinforcement”) and a method of constructing the same.

[0002]

2. Description of the Related Art It has been proposed to cut a gentle slope of a railway or a road having a substantially trapezoidal cross section and make it a steep slope to make effective use of land. In this case, it is important to prevent the cut slope from collapsing. As a construction method for stabilizing a cut slope, for example, a reinforcing steel reinforced earth construction method of driving a plurality of reinforcing bars into the ground for reinforcement is known.

[0003]

Problems to be Solved by the Invention The conventional ground reinforcement technique has the following problems.

<A> Since the rebar used has a small diameter of about 30 mm, a large friction area with earth and sand cannot be secured. Also, the drilling grout type has a drilling diameter of about 70 mm, so that a large adhesion area with earth and sand cannot be obtained. Therefore, the pull-out resistance per unit length of the reinforcing bar is small, and it is difficult to obtain a sufficient ground reinforcing effect.

<B> The number of reinforcing bars used is large, and the reinforcing cost is high.

<C> As a method of reducing the number of used reinforcing bars, a method of using a long reinforcing bar to lengthen the driving length per bar can be considered. However, the longer the entire length of the rebar is, the more difficult and uneconomical the work of placing the rebar is.

<D> Reinforcing bars have a relatively small resistance bending moment, and therefore have a limited effect on ground reinforcement.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a reinforcing body having a high reinforcing effect on the ground and a method for constructing the reinforcing body.

[0009]

Means for Solving the problems] The present invention, drilling
The excavation slope of the ground by excavating stirrer having Kezutsubasa and a stirring blade from the side and excavated soil obtained by digging the columnar 攪
A columnar improved body formed by stirring and mixing the solidified material liquid discharged from the tip of the stirring device in situ , and a hollow cylindrical core material inserted into the improved body A large-diameter bending tensile reinforcing body having a core material and an inner and outer peripheral surface adhered to the improved body to build a composite structure of the improved body and the core material to reinforce the slope ground.

Further, according to the present invention, the vicinity of the tip of the hollow rod is provided.
Side of the slope with excavating wings and stirring wings
Excavated in a columnar shape from the
Stir and mix the solidified material discharged from the rod to form an improved body
Formed, remove the hollow rod from the improved body, and
Insert a hollow cylindrical core into the body and clean the inner and outer peripheral surfaces of the core.
Attached to the improved body to build a composite structure of the improved body and core material
Of large-diameter bending tensile reinforcement to reinforce slope ground
In the way .

The present invention further provides a hollow cylindrical core material having a hollow shape.
Sheathed on the rod and placed near the tip of the hollow rod
Excavation wings and agitating wings make the slope ground into a columnar shape from the lateral direction.
Excavation and discharge from the excavated soil and hollow rod
Stir and mix the solidified material to form an improved body,
Insert the core into the improved body, leave the core in the improved body,
Take out the pad and attach the inner and outer peripheral surfaces of the core material to the improved body
Reinforce slope ground by constructing composite structure of improved body and core material
To construct a large-diameter bending tensile reinforcement .

[0012]

In the reinforcing body constructed in this manner, the inner and outer peripheral surfaces of the cylindrical core material inserted into the improved body serve as friction resistance surfaces.
The pull-out resistance of the reinforcement increases. Further, the resistance bending moment of the cylindrical core material is larger than that of the solid core material with the same cross-sectional area, and the bending resistance and the shear resistance of the reinforcing body increase due to the combined effect of the improved body. In addition, the resistance to pulling out and bending of the reinforcing body is increased, so that the ground reinforcing effect is improved. The excavated soil and the solidified material are agitated and mixed in the ground without discharging the excavated soil during the construction of the reinforcing member, so that there is no fear that the surrounding ground is loosened. By providing a spacer for preventing misalignment on the outer peripheral surface of the core material, misalignment of the core material can be prevented. Also, if spiral blades are provided on the outer peripheral surface of the core material,
The misalignment can be prevented, and the work of rotating and inserting the core material becomes easy. In addition, when the core is inserted or rotated while the improved body is being built with the excavating and stirring device, the reinforcing body can be efficiently built compared to the case where the core is inserted after the improved body is built. it can.

[0013]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

<A> Reinforcement

FIG. 1 shows a whole view of cutting slope 20 using reinforcing body 10, and FIG. 2 shows cutting slope 2 after construction.
0 shows a sectional view. The reinforcing body 10 is a columnar improved body 11 constructed by stirring and mixing the cut slope 20 while injecting the solidifying material.
And a cylindrical core material 12 penetrating the improved body 11.

<B> Core material

The core material 12 is a hollow cylinder having both ends open to increase the pull-out resistance with respect to the improved body 11 and the bending strength of the improved body 11, and is made of a rigid body such as a steel pipe.
The diameter of the core material 12 may be slightly smaller than that of the improved body 11. Also, the total length of the core material 12 is slightly longer than the total length of the improved body 11,
It is only necessary that one end protrudes from the cut slope 20. This is because the retaining wall 22 covering the cut slope 20 and the reinforcing body 10 are integrated as shown in FIG. As a method of achieving the integration, a method of embedding the end of the core material 12 constituting the reinforcing body 10 in the retaining wall 22 and directly connecting the same is available, and a method of separately providing between the reinforcing bar constituting the retaining wall 22 and the core material 12. And a method of indirectly connecting by welding the connecting reinforcing bars. Since the cut slope 20 can be sufficiently reinforced by the reinforcing body 10, it is not necessary to project one end of the core material 12 from the cut slope 20 when a retaining wall is not required. Note that the other end of the core material 12 may have a length penetrating the improved body 11.

[0018]

[Operation] Next, a method of reinforcing a cut slope using a reinforcing body will be described.

<A> Partial cut

As shown in FIG. 1, a cut slope 20 is formed by cutting the upper part of the gentle slope 21 at a predetermined slope. Gentle slope 2
The cutting range 1 is set to such an extent that the cut slope 20 does not collapse.

<B> Construction of reinforcement

The reinforcing body 10 is built on the exposed cut slope 20 in the following manner. First, the improved body 11 is constructed on the cut sand surface 20 by using the excavating and stirring device 30. Drilling and stirring device 30
Has an excavating wing 32 at the tip of a hollow hollow rod 31 and has a plurality of agitating wings 33 fixed behind it, and the digging wings 32 are attached to the hollow rod 31 between the excavating wings 32 and the agitating wings 33.
A longer anti-corotating wing 34 is rotatably mounted so that a solidified material such as cement milk supplied from the base end of the hollow rod 31 can be discharged from the vicinity of the front end of the hollow rod 31. Then, the excavating and stirring device 30 is rotated to start supplying the solidified material from the base end of the hollow rod 31. With the rotation of the hollow rod 31, the excavating wing 32 penetrates the cut slope 20, and the stirring blade 33 stirs and mixes the solidified material discharged from the tip of the hollow rod 31 with the shaved soil. as a result,
The column-shaped improved body 11 is constructed.

<B> Recovery of the excavating and stirring device

When the excavating and stirring device 30 has been dug to a predetermined depth, the excavating and stirring device 30 is reversed and extracted from the improved body 11. At this time, the solidified material is discharged from the distal end of the hollow rod 31, and the excavating and stirring device 30 is withdrawn while being stirred and mixed by the excavating blade 32. The reason why the solidified material is discharged when the excavating and stirring device 30 is collected is to replenish the space generated by the collection of the excavating and stirring device 30 and to prevent the surrounding ground from becoming loose.
The structure of the improved body 11 can be made more compact by appropriately adjusting the reverse rotation speed of the excavating and stirring device 30 and the overall withdrawal speed.

<C> Penetration of core material

Next, the cylindrical core material 1 is added to the improved body 11 before curing.
2 to obtain the reinforcing body 10. The step of partially cutting the gentle slope 21 from above and the step of constructing the reinforcing body 10 on the cut slope 20 are repeated.

<D> Retaining wall work

Finally, the retaining wall 22 may be constructed by placing concrete after arranging reinforcing bars on the entire cut slope 20.
In this case, one end of the core material 12 of each reinforcing body 10 exposed on the entire cut slope 20 is connected to the retaining wall 22 to form an integral structure.

<E> Function of reinforcing body

In FIG. 2, an axial tensile force due to a horizontal earth pressure and a vertical bending force act on each reinforcing member 10. Although the strength of the core material 12 mainly resists the tensile force in the axial direction, since the improved body 11 particularly adheres to the inner and outer peripheral surfaces of the cylindrical core material 12 to secure a wide contact area. In addition, the strength of the core material 12 can be effectively used, and the pull-out resistance of the reinforcing body 10 increases. Further, with respect to the bending force in the longitudinal direction, the core member 12 is a cylindrical body, so that the bending resistance is larger than that of a solid body having the same cross-sectional area, and the strength of the cross-section synthesis with the improved body 11 is large. Accordingly, the resistance bending moment of the reinforcing body 10 increases.

[0031]

Second Embodiment As shown in FIG. 3, a plurality of spacers 13 may be attached to the outer peripheral surface of a cylindrical core material 12 along the circumferential direction. The spacers 13 are preferably provided at predetermined intervals along the axial direction of the core material 12. In the present embodiment, there is an advantage that when the core material 12 is inserted into the improved body 11 or after insertion, the core material 12 can be prevented from falling (misalignment) with respect to the improved body 11.

[0032]

Third Embodiment As shown in FIG. 4, the core member 12a may be a rebar basket in which the circumference of a plurality of main bars 12b arranged in a columnar shape is restricted by a hoop bar 12c.

[0033]

Fourth Embodiment FIGS. 5 and 6 show another embodiment in which the construction of the improved body 11 and the insertion of the cylindrical core material 12 are performed in one operation step.

[Structure] First, main equipment will be described.

<A> Core material

The cylindrical core member 12e has one or more spiral blades 14 on the outer peripheral surface of the tip. The blades 14 rotate the core 12e to facilitate penetration into the improved body 11, and like the spacers, the core 12e
It also has the function of preventing descent. It is also possible to use the core material of each embodiment described above for the core material 12e.

<B> Drilling and stirring device

In this embodiment, a digging and stirring device 40 as shown in FIG. 6 is used. The excavating and stirring device 40 includes the hollow rod 4
1 has a cutting wing 42 at its tip, and a co-rotation preventing wing 43 is rotatably mounted on a hollow rod 41 behind the cutting wing 42. Further, a stirring blade 50 is mounted on the hollow rod 41 behind the co-rotation prevention blade 43. Further, in the middle of the hollow rod 41, the hollow rod 41 is
The internal spacer 44 positioned at the axis of e is loosely fitted. At the tip of the hollow rod 41, a discharge port 45 capable of discharging a solidified material such as cement milk is formed.
5 is provided with a check valve function for preventing backflow of the discharged solidified material. Each wing 42, 43, 50 is provided with a supporting shaft 46, 4
7, 51, and the support shafts 46, 47,
The swing is restrained by stop pins 48, 49, 52 of lower strength than 51, and the wings 42, 43, 50 swing about the spindles 46, 47, 51 due to damage of the stop pins 48, 49, 52. By moving, the diameter can be reduced to be smaller than the inner diameter of the core material 12e.

[Method of Building Reinforcement]

<A> Construction of reinforcement

As shown in FIG. 5A, a cylindrical core material 1 is formed.
While discharging the solidified material from the vicinity of the tip of the excavating and stirring device 40 inserted in 2e, the excavating and stirring device 40 and the core material 12e are respectively rotated in opposite directions to penetrate the cut slope 20. The excavated soil excavated by the rotation of the excavating blade 42 is
Rotates and builds the improved body 11 while mixing and stirring with the solidified material. In parallel with the construction of the improved body 11, the cylindrical core material 1
2e penetrates while rotating inside the improved body 11, and the reinforcing body 1
0 is gradually extended. Thus, in the present embodiment, the excavation / stirring device 40 and the core 12e are simultaneously penetrated,
Construction of the improved body 11 and rotation penetration of the core material 12e can be performed simultaneously. When the core material 12e does not have the blade 14, the core material 12e may be inserted without rotation.

<B> Recovery of the drilling and stirring device

As shown in FIG. 5B, the excavating and stirring device 4
0 and the core material 12e have penetrated to a predetermined depth, and as shown in FIG.
Only the core material 12e is left in the improved body 11. That is, as shown in FIG. 6, when the excavating and stirring device 40 is pulled out while holding the core 12e so as not to come out, the core 12e is removed.
After the stirring blade 50 abuts on the end of the core member 12e, the stopper pin 52 is broken, the stirring blade 50 is closed, and is introduced into the core material 12e.
Similarly, the co-rotation prevention blade 43 and the excavation blade 42 are closed and introduced into the core material 12e to be collected. It should be noted that when extracting the excavating and stirring device 40, the solidification material is discharged while rotating while being discharged, as in the above-described embodiment.

<C> Effects of the present embodiment

In this embodiment, since the reinforcing body 10 can be built in one process, the construction efficiency is good, the construction period can be shortened, and the construction cost can be reduced.

[0046]

Embodiment 5 Core Material 1 Used in Each of the Above Examples 1-4
2, 12a and 12e may be recombined. Also, the gentle slope 21 itself may be reinforced by applying the above-described embodiments 1 to 4 to the gentle slope 21.

[0047]

The present invention has the following unique effects.

<A> Since the inner and outer peripheral surfaces of the cylindrical core material inserted into the improved body can be used as friction resistance surfaces, the pull-out resistance of the reinforcing body increases.

<B> The resistance bending moment of the cylindrical core material is larger than that of the solid core material, and the bending resistance and the shear resistance of the reinforcing body increase due to the combined effect with the improved body.

<C> Since the resistance to pulling out and bending of the reinforcing body increases, a high ground reinforcing effect can be obtained.

<D> Since the shaving is mixed with the solidified material in the ground without excavating the ground, there is no fear that the surrounding ground is loosened.

<E> By providing a spacer integrally on the outer peripheral surface of the core, misalignment due to the weight of the core can be effectively prevented.

<F> When a reinforcing bar is used as the core, the pull-out resistance of the core increases due to the cooperation between the adhesion resistance of the main bar and the bearing resistance of the hoop bar. Moreover, compared with the case of steel pipe, it is more economical in terms of material cost and transportation cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a reinforcing body according to a first embodiment.

Fig. 2 Cross section of cut slope after construction

FIG. 3 is an explanatory view of a second embodiment using a core material with a spacer.

FIG. 4 is an explanatory view of a third embodiment using a reinforced cage as a core material.

FIG. 5 is an explanatory view of Embodiment 4 in which a reinforcing body is built in one step.

FIG. 6 is an enlarged view of a tip of a drilling and stirring device used in a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reinforcement body 11 Improved body 12 Core material 12a Core material made of reinforced cage 12e Core material with blades 13 Spacer 14 Spiral blade 20 Cut slope 21 Slow slope 22 Retaining wall 30 Drilling and stirring device 31 Hollow rod 32 Drilling wing 33 Stirring blade 34 Anti-corotating wing 40 Drilling stirrer 41 Hollow rod 42 Excavating wing 43 Co-rotating anti-wing 44 Internal spacer 45 Discharge port 46 Support shaft for supporting the anti-rotation wing 47 Excavating shaft 48 Excavating Stop pins that support the blades 49 Stop pins that support the anti-rotation blades 50 Stirring blades 51 Shafts that support the stirring blades 52 Stop pins that support the stirring blades

Continued on the front page (72) Inventor Masaru Tateyama 38-8 Hikaricho, Kokubunji-shi, Tokyo Inside the Railway Technical Research Institute (72) Inventor Yukihiko Tamura 2-22-15- Katsuradai, Midori-ku, Yokohama-shi, Kanagawa 106 (72) Inventor Kosei Fukuda 2-4-1 Akasaka, Minato-ku, Tokyo Inside Tenox Co., Ltd. (72) Inventor Shigeru Yoshida 2-4-1 Akasaka, Minato-ku Tokyo, Inside Tenox Co., Ltd. (72) Inventor Shushi Kami 2-4-1 Akasaka, Minato-ku, Tokyo Inside Tenox Co., Ltd. (56) References JP-A-60-238515 (JP, A) JP-A-2-304119 (JP, A) JP Hei 4-323496 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 17/00 E02D 5/50 E02D 17/20 E21D 9/04

Claims (7)

(57) [Claims] 1. A drilling and stirring device having a drilling blade and a stirring blade.
Excavated soil obtained by excavating a more sloped ground into a column shape from the lateral direction and solidified material discharged from the tip of the excavation stirring device
It has a columnar improved body formed by stirring and mixing the liquid in situ , and a hollow cylindrical core material inserted into the improved body, and the inner and outer peripheral surfaces of the core material adhere to the improved body. A large-diameter bending tensile reinforcement that reinforces the slope ground by building a composite structure of the improved body and core material. 2. The large-diameter bending tensile reinforcing body according to claim 1, wherein at least one spacer for preventing misalignment is provided on an outer peripheral surface of the core material. 3. The large-diameter bending tensile reinforcement according to claim 1, wherein a spiral blade is provided on an outer peripheral surface of the core material. body. 4. The large-diameter bending tensile reinforcement according to claim 1, wherein a base end of the core is integrally connected to a lining covering the slope. , Large diameter bending tensile reinforcement. 5. Excavation of a sloped ground into a columnar shape from a lateral direction by a drilling wing and a stirring blade arranged near a tip end portion of a hollow rod, and excavated soil and a solidified material discharged from the hollow rod. To form an improved body, remove the hollow rod from the improved body, insert a hollow cylindrical core material into the uncured improved body, and attach the inner and outer peripheral surfaces of the core material to the improved body to improve it. A method of constructing a large-diameter bending tensile reinforcement that builds a composite structure of the body and core material to reinforce the slope ground. 6. A hollow cylindrical core material is sheathed on a hollow rod, and an excavation wing and a stirring wing arranged near the tip of the hollow rod are used to excavate the ground on a slope from a lateral direction into a columnar shape.
The improved excavated soil and the solidified material discharged from the hollow rod are stirred and mixed to form an improved body, the core material is further inserted into the improved body, the core material is left in the improved body, and the hollow rod is taken out. A method of constructing a large-diameter bending tensile reinforcement, in which the inner and outer peripheral surfaces of the core material are attached to the improved body to build a composite structure of the improved body and the core material to reinforce the slope ground. 7. The method for constructing a large-diameter bending tensile reinforcing body according to any one of claims 5 and 6, wherein a core material having spiral blades on an outer peripheral surface is inserted into the improved body while rotating. Characteristic, construction method of large-diameter bending tensile reinforcement.