JP5555050B2 - Construction structure of rebar insertion work using composite rebar - Google Patents

Description

  The present invention relates to a construction structure of a reinforcing bar insertion work that uses a composite reinforcing bar that can reduce the number of constructions and has a high effect of suppressing deformation of natural ground in the reinforcing bar insertion work.

  Reinforcing bar insertion is generally a method called rock bolting, but it is called a reinforcing bar insertion because it can be applied to other than rock. Reinforcing bar insertion work cannot give tension like ground anchor work. In other words, it is a construction method premised on the movement of the natural ground that the tensile force is generated in the reinforcing bar only after the natural ground moves, and the deterrent effect on the natural ground like the anchor appears.

FIG. 7 shows a conceptual diagram for each ground of the reinforcing bar insertion work.
As shown in FIG. 7A, in the rock mass, a shearing force mainly acts on the sliding surface 32 of the moving rock mass 31, and a sufficient resistance force is obtained by the inserted reinforcing bar 33. However, as shown in FIG. 7B, not only concentrated shearing force but also surface stress in a soft layer where a distributed load from the moving mass 34 acts, not only shearing stress but also bending stress is generated.
The resistance mechanism of rebar insertion work is that bending resistance first occurs and then transitions to tensile resistance, but this bending resistance is generally ignored in bedrock.
On the other hand, in a soft formation, the pulling resistance of the moving mass 34 is small, so the effect of the reinforcing bar insertion work is determined by the resistance force in the moving mass 34. Therefore, a larger number of constructions are required, which is uneconomical.
FIG.7 (c) is the method of using the reinforcing bar insertion work 35 which added the conditions similar to the head fixing pad employ | adopted by the landslide in a soft formation.

  In the non-frame method applied to the soft ground surface slide shown in FIG. 8, the head employed in the landslide shown in FIG. 7 (c) is obtained by fixing the head of the reinforcing bar 41 together with the bearing plate 42. It is designed on the assumption that the same effect as that of the fixing pile {35 in FIG. 7 (c)} can be obtained. Specifically, a design system that evaluates the bending resistance generated at the initial stage of reinforcing bar insertion as a reinforcement effect coefficient is adopted.

  Details of the non-frame construction method are shown in Patent Document 1. In Patent Document 1, an anchor pin is driven into the ground, the center through hole of the bearing plate is fitted into the ground protruding end of the anchor pin, and then the nut is screwed from the protruding end of the anchor pin, and the crossing portion of the wire rope is It is described that the bearing plate is pressed down.

JP 2004-316374 A

  The problem with the non-frame construction method is that the bearing plate must be embedded to a fairly hard layer in order to satisfy the head fixing condition. However, it is difficult in reality and is hardly implemented. This is because, usually, topsoil such as a corrosive soil layer is often distributed, and if a plant and topsoil are removed, a new vegetation work is required. Therefore, in most cases, it is installed on topsoil. For this reason, it is doubtful whether head fixation conditions are satisfied.

Therefore, if the above-mentioned neglected bending resistance is considered as the resistance force, the effect is great because the resistance force of the reinforcing steel bars is small, and the number of constructions can be reduced.
From the above, it can be seen that, in the reinforcing bar insertion work in soft ground, if a resistor having a large bending rigidity is adopted, a countermeasure work with higher effect is obtained. The present invention focuses on this point.

  In view of the above situation, the present invention provides a construction structure for reinforcing bar insertion work that uses a composite reinforcing bar that can reduce the number of constructions and has a high effect of suppressing deformation of natural ground in the reinforcing bar insertion work. With the goal.

In order to solve the above problems, the present invention provides the following configurations.
The invention according to claim 1 is a construction structure of a reinforcing bar insertion work that stabilizes a natural ground by inserting a reinforcing bar into a drill hole filled with a grout, and the reinforcing bar is formed in a shorter length than the reinforcing bar. inserted into the tubular body, Rutotomoni passed through, a composite rebar is brought into close contact with the reinforcing bar in the hollow tubular body is formed by inserting the formed rod-like body to said hollow tubular body into a length shorter than the reinforcing bars The construction structure of the reinforcing bar insertion work using the composite reinforcing bar, wherein the composite reinforcing bar is inserted into the drilling hole.

According to a second aspect of the present invention, there is provided a construction structure for a reinforcing bar insertion work using the composite reinforcing bar according to the first aspect , wherein the hollow tubular body is subjected to anticorrosion treatment .

  According to a third aspect of the present invention, the hollow tubular body is formed to have a length from the surface layer of the sliding soil block of the soft construction ground to a deeper part than the sliding surface, and the composite rebar is inserted into the drilling hole. The hollow tubular body is disposed from the surface layer of the surface sliding soil block to a deeper part than the sliding surface, and is configured to suppress surface slip of the surface sliding soil block. The construction structure of the reinforcing bar insertion work using the composite reinforcing bar described in 2 is provided.

  The invention according to claim 4 is, in the aging mortar spray repair work, the hollow tubular body is formed in a length exceeding the bottom of the natural weathering zone from the aging mortar spraying surface layer of the construction ground, the composite rebar, When inserted into a drilling hole, the hollow tubular body is disposed in a range from the surface layer of the aging mortar spraying to the bottom of the natural weathering zone, preventing fall and repair / repairing during the construction of the aging mortar spraying work. It is comprised so that reinforcement may be performed, The construction structure of the reinforcing bar insertion work using the composite reinforcing bar of Claim 1 or 2 characterized by the above-mentioned is provided.

  According to the invention described in claim 1 of the present invention, in the reinforcing bar insertion work, it is possible to reduce the number of constructions, and the construction structure of the reinforcing bar insertion work using the composite reinforcing bar that has a high effect of suppressing deformation of the natural ground. Can be provided.

According to the invention described in claim 1 , the rod-shaped body is inserted into the hollow tubular body, and the reinforcing bar is brought into close contact with the hollow tubular body, whereby the hollow tubular body is stably held by the reinforcing bar, and the shear resistance and Flexural rigidity is added.

  According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or 2, the hollow tubular body is disposed from the surface layer of the slip layer of the soft construction ground to the deeper part than the slip surface. The hollow tubular body increases bending resistance and shear resistance due to the surface sliding soil block, and can suppress deformation such as movement of the surface sliding soil block and generation of cracks on the soft construction ground.

According to the invention described in claim 4, in addition to the effect of the invention described in claim 1 or 2, in the repair work for aging mortar spraying, the range in which the hollow tubular body exceeds the bottom of the natural weathering zone from the surface layer of the aging mortar spraying Therefore, it is possible to effectively prevent the deformation of the surface layer of the aging mortar and the weathering zone, and to prevent the fall and repair / reinforcement of the aging mortar spraying works. it can. It is also possible to reduce the number of constructions.
Furthermore, the aging mortar spraying repair work which is more effective can be performed by spraying the mortar on the reinforced mortar spraying part and integrating them.

It is side surface sectional drawing of the construction structure of the reinforcing bar insertion work using the composite reinforcing bar of this invention. It is a side view of the composite reinforcing bar of the present invention. It is front sectional drawing of the composite reinforcing bar of this invention. It is explanatory drawing of the bending and shear resistance which generate | occur | produce in the construction structure of the reinforcing bar insertion work using the composite reinforcing bar of this invention. It is a figure which shows the example of application to the aging mortar spray life extension construction of the construction structure of the reinforcing bar insertion construction using the composite reinforcement of this invention. It is a figure which shows the example of application to the aging mortar spray reinforcement work of the construction structure of the reinforcement insertion work using the composite reinforcement of this invention. (A) It is explanatory drawing of the shear resistance force generate | occur | produced when the conventional reinforcing bar insertion work is applied to a moving rock block. (B) It is explanatory drawing of the bending and shear resistance which generate | occur | produce when the conventional reinforcing bar insertion work is applied to a soft moving soil block. (C) It is explanatory drawing of the bending and shear resistance which generate | occur | produce when a head fixing condition is added to the conventional reinforcing bar insertion work. It is side surface sectional drawing which shows a non-frame construction method (similar construction method).

Hereinafter, embodiments of the present invention will be described with reference to the drawings showing examples.
1 and 2 show a construction structure of a reinforcing bar insertion work using the composite reinforcing bar of the present invention. The construction structure of the reinforcing bar insertion work using the composite reinforcing bar of the present invention is formed with a hole diameter of about φ40 mm to φ90 mm, and is made of cement. In the construction structure of the reinforcing bar insertion work that stabilizes the natural ground 3 by inserting the reinforcing bar 2 into the drill hole 1 filled with grout such as paste, the reinforcing bar 2 is formed in a hollow tube having a shorter length than the reinforcing bar 2 It is a construction structure of a reinforcing bar insertion work that is inserted into a body (steel pipe or the like) 4 and penetrated to form a composite reinforcing bar 5 and the composite reinforcing bar 5 is inserted into the drilling hole 1.

  And the rod-shaped body (rebar etc.) 6 shown in FIG. 3 formed in the length shorter than the said reinforcing bar 2 is inserted in the hollow tubular body 4. As shown in FIG. As shown in FIG. 3, two rod-like bodies 6 may be inserted into the hollow tubular body 4. Moreover, the rod-shaped body (rebar etc.) 6 is formed in substantially the same length as the hollow tubular body 4, for example. The rod-like body 6 is inserted into the hollow tubular body 4, and the reinforcing bar 2 is brought into close contact with the hollow tubular body 4, whereby the hollow tubular body 4 is stably held by the reinforcing bar 2, and shear resistance and bending rigidity are added. The

  The hollow tubular body 4 is subjected to anticorrosion treatment and is formed to have a length from the surface layer of the surface sliding soil block 7 of the construction ground to a deeper part than the sliding surface 8, and the composite rebar 5 is inserted into the drilling hole 1. When this is done, the hollow tubular body 4 is disposed from the surface layer of the surface layer sliding soil mass 7 to a deeper part than the sliding surface 8. The hollow tubular body 4 is integrated with the reinforcing bar 2 and the rod-shaped body 6 by the grout in the drilling hole 1 and is configured to suppress the surface layer slip of the surface layer sliding soil mass 7.

The composite pile used in the conventional landslide is a combination of steel pipe and H steel over the entire length, but the construction structure of the reinforcing bar insertion work using the composite reinforcing bar of the present invention is the upper level (slip surface 8) ( The difference is that the hollow tubular body 4 and the rod-shaped body 6 are installed at the upper position). That is, the hollow tubular body 4 and the rod-shaped body 6 are formed to have a length shorter than that of the reinforcing bar 2, and the hollow tubular body 4 has a length from the surface layer of the surface sliding soil block 7 of the construction ground to a deeper part than the sliding surface 8. The rod-shaped body 6 is inserted into the hollow tubular body 4.
As a result, a composite structure in which the functions of both the anchor and the anchor are exhibited.

The construction sequence of the construction structure of the reinforcing bar insertion work using the composite reinforcing bar of the present invention is as follows.
After completing the drilling 1 work on the construction ground, insert the injection pipe to the bottom of the drilling hole 1 and inject grout such as cement paste from the tip to fill the hole of the drilling hole 1, then inside the drilling hole 1 The composite rebar 5 is inserted into Thereby, the inside of the hollow tubular body 4 is also filled with grout. At this time, the grout overflowing from the hole 1 and the hollow tubular body 4 falls.
When it is confirmed that the grout has developed the predetermined strength, the plate 9 is installed by filling the hollow formed by the hardening of the grout with mortar, and the plate 9 is tightened using the nut 10 so as not to be loosened. finish.

In the case of the example shown in FIG. 3, the added rigidity is calculated as shown in Table 1.
The constituent materials in this case are as follows.
Reinforcing bars: main reinforcing bar D-19, auxiliary reinforcing bar D-13
Steel pipe: SGP-32 (outer diameter φ42.7 inner diameter φ35.7)

The construction structure of the reinforcing bar insertion work using the composite reinforcing bar according to the present invention eliminates the need for the bearing plate (42 in FIG. 8) in the conventional non-frame construction method applied to the surface slip of the soft ground shown in FIG. The purpose is to obtain a similar effect. As shown in FIG. 4, the bending rigidity of the reinforcing bars 2 of the moving mud portion of the surface sliding mud 7 is increased to prevent the occurrence of bending deformation. This is to obtain the same effect as the condition for fixing the rake head.
That is, by forming a composite rebar 5 in which a rigid additive material such as a steel pipe is combined, such as the hollow tubular body 4, the occurrence of deformation is suppressed by increasing the rigidity of the soft portion near the surface of the surface sliding soil mass 7, etc. The effect of rebar insertion work is enhanced by increasing the bending or shear resistance. That is, the resistance is increased by making the effect of the reinforcing bar insertion work similar to that of hard ground.

  The present invention is a construction structure of a reinforcing bar insertion work that uses a composite reinforcing bar 5 that is constructed with a simple drilling device and suppresses surface slip and stabilizes the ground as described above, and is the same as a normal reinforcing bar insertion work. After drilling with the hole diameter and filling the hole with grout, a member (composite rebar 5) with partially increased rigidity is inserted. In particular, the following effects can be obtained by partially increasing the rigidity.

(Effect 1) A greater deterrent effect can be obtained with less investment.
Applying deterrent piles and anchors used for landslide countermeasures to surface slips will result in an uneconomic design. For this reason, recently, many reinforcing bar inserters have been adopted. However, it is a disadvantage that a large number of reinforcing bar insertion works are necessary for the surface slip of a soft ground layer.
Most of the cost of reinforcing bar insertion work is accounted for by drilling, and reducing the number of constructions is more economical. In order to reduce the number of constructions, it is necessary to increase the adhesion resistance between the moving block (surface sliding block 7) and the reinforcing bar 2, but it is uneconomical to increase the drilling diameter. Therefore, inventing the composite rebar 5 in which the bending resistance, which is neglected because it is small in the design system of the rebar insertion work, is increased to a size that can be evaluated, and the bending rigidity is partially increased in order to realize the effect of deterring piles. It was. The partial composite structure is to leave the anchor-like deterrent effect of the reinforcing bar insertion work.
By adopting the composite rebar 5, bending resistance and shear resistance in the moving soil mass are increased. It was possible to reduce the number of constructions by adding the effect to the design of ordinary rebar insertion work.

Table 2 compares the construction interval and the head displacement for the reinforcing bar insertion rebar and the composite reinforcing bar 5 in Table 1 using the structural analysis used for deterrent pile design used for landslide countermeasures. For the assumed deterrence, the magnitude of the resistance is conveniently evaluated by finding the construction interval that reaches the allowable limit.
Each condition is as follows.
Example of study when necessary deterrence force Pr = 100 N / m Sliding layer thickness It = 2 m: Calculation condition → Bending restraint pile Ground condition: Fixing to fixed ground with N value 50

  From Table 2, it can be seen that the effect of bending resistance is increased by a factor of 4 by changing to a composite rebar. Therefore, the number of constructions can be reduced to about 1/4 in simple calculation. In the rebar insertion work, it is not a simple ¼ because it is a combination of the initial bending resistance and the subsequent pulling resistance. It is increasing. Therefore, a more rational and economical countermeasure work can be implemented by incorporating this increased bending resistance into the design system of the reinforcing bar insertion work.

(Effect 2) Deformation suppression effect Compare with the head displacement amount of the reinforcing bar insertion work in Table 2. In the case of the same arrangement as that of D-19 alone, the load is reduced to ¼, so that the head deformation is ３, so the deformation can be reduced to 1/12. This shows that the effect of suppressing deformation of the natural ground is remarkable.
This indicates that the structure is such that the deterrent effect is exhibited in a state where there is little looseness of the natural ground. Suppressing natural deformation can prevent the progress of weathering due to the occurrence of natural cracks after construction, reducing elements that will become unstable in the future, and reducing the total life cycle cost of the entire slope. It can be said that it is a construction method that can be used.

(Effect 3) Addition of anti-corrosion function Inserting a hollow tubular body (steel pipe, etc.) that has been subjected to anti-corrosion treatment into a moving clot that has a great potential to adversely affect the corrosion of the rebar, will reinforce the rebar at the site where corrosion is most concerned The double anti-corrosion function is added to. Thereby, durability performance improves.

  The construction structure of the rebar insertion work using the composite rebar of the present invention described above is used to prevent surface slip such as a slope appearing on a new road, or when you want to implement countermeasures by leaving a standing tree in steep slope collapse construction. Can be adopted.

The construction structure of the reinforcing bar insertion work using the composite reinforcing bar of the present invention is further used as a fall prevention measure during the construction of the life extension measure of the aging mortar spraying work reaching the renewal time as shown in FIG.
In this case, the hollow tubular body 4 is formed to a length exceeding the bottom of the ground weathering zone 22 from the aging mortar sprayed surface layer 21 of the construction ground, and when the composite rebar 5 is inserted into the drilling hole 1, the hollow tubular body 4 is formed. The body 4 is disposed in a range beyond the aging mortar spraying surface layer 21 and the bottom of the natural weathering zone 22. Because the deformation prevention function is high, safety during construction is ensured. A permeable concrete sprayer 24 is constructed in the lower mortar removal section, and the life extension of the mortar is completed.

Moreover, it is employable as an anti-aging mortar spraying countermeasure as shown in FIG.
In this case, the hollow tubular body 4 is formed to have a length exceeding the bottom of the natural weathering zone 22 from the aged mortar spraying surface layer 21, and when the composite rebar 5 is inserted into the drilling hole 1, the hollow tubular body 4 is The mortar spraying surface layer 21 is disposed in a range beyond the bottom of the natural weathering zone 22 to reinforce the aging mortar spraying work.
Aged mortar and weathered ground are stabilized by being integrated with unweathered ground, but it has a structure in which shear resistance can be increased and deformation can be prevented as compared with ordinary reinforcing bar insertion work.
Conventionally, in order to prevent the deformation of the aging mortar, spray method frame work + rebar insertion work is adopted, but it is obsolete by inserting the composite rebar in the construction structure of the rebar insertion work using the composite rebar of the present invention. Since it is possible to prevent the deformation of the plasticized mortar, it is not necessary to use the spray method frame work in combination, which is an economical measure.

DESCRIPTION OF SYMBOLS 1 Drilling hole 2 Reinforcing bar 3 Ground mountain 4 Hollow tubular body 5 Composite reinforcing bar 6 Rod-like body 7 Surface sliding soil block 8 Sliding surface 21 Aging mortar spraying surface layer 22 Ground mountain weathering zone 24 Permeable concrete spraying work

Claims (4)

In the construction structure of the reinforcing bar insertion work that stabilizes the natural ground by inserting the reinforcing bar into the hole filled with the grout, the reinforcing bar is inserted into the hollow tubular body formed with a length shorter than the reinforcing bar and penetrated. And forming a composite rebar in which the rebar is in close contact with the hollow tubular body by inserting a rod-like body having a shorter length than the rebar into the hollow tubular body, and forming the composite rebar into the drilling hole Reinforcing bar construction work using composite rebar, which is characterized by being inserted inside. The construction structure of the reinforcing bar insertion work using the composite reinforcing bar according to claim 1, wherein the hollow tubular body is subjected to anticorrosion treatment.   The hollow tubular body is formed to have a length from the surface layer of the sliding soil block of the soft construction ground to the deeper part than the sliding surface, and when the composite rebar is inserted into the drilling hole, the hollow tubular body is The reinforcing bar using the composite reinforcing bar according to claim 1 or 2, wherein the reinforcing bar is arranged from the surface layer of the surface layer sliding soil mass to a deeper part than the sliding surface, and is configured to suppress the surface layer sliding of the surface layer sliding soil mass. The construction structure of the inserter.   In the aging mortar spray repair work, the hollow tubular body is formed to have a length exceeding the bottom of the natural weathering zone from the aging mortar spray surface of the construction ground, and when the composite rebar is inserted into the drilling hole. The hollow tubular body is arranged in a range from the surface layer of the aging mortar spraying to the bottom of the natural weathering zone, and is configured to prevent fall, repair and reinforcement during the construction of the aging mortar spraying work. A construction structure of a reinforcing bar insertion work using the composite reinforcing bar according to claim 1 or 2.

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