JP3232481B2 - Support structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength support structure which can be used as a support fence of a protective fence on which a large impact energy such as a falling rock acts.

[0002]

2. Description of the Related Art Posts for guard fences such as falling rocks and avalanches are required to have extremely high rigidity from the viewpoint of ensuring safety, and are constituted by a reinforced concrete structure, a steel reinforced concrete structure, a prestressed structure, or the like.

However, these structures have poor toughness,
After reaching the maximum proof strength, the proof strength is rapidly lost and the kinetic energy of the falling rock cannot be completely absorbed because the crush energy does not have sufficient deformation ability. Japanese Patent Application Laid-Open No. Hei 6-146225 has previously been filed as a column for obtaining high bending strength. This pillar is used to place an unbonded PC material in a steel pipe, fill it with concrete, and fix it by attaching fixing devices to both ends of the non-tensioned PC material. The structure is such that prestress is introduced.

According to the composite structure, a PC steel rod is used as a tensile member. Generally, this type of strut may be formed such that its upper portion is curved toward the road. However, in a bent steel pipe, a similarly bent P
It is difficult to dispose the C steel bar because it passes through a combination of a straight line and a curved line. Further, if a flexible PC steel strand can be used for the PC material, it is possible to cope with the bending of the steel pipe, but the initial state is a non-tensioned state, and the tension is rapidly applied at the time of a falling rock collision. Due to problems such as wires coming off the PC steel due to the fixing structure, PC
The use of steel strands is forgotten. That is, the structure is P
This is because a known wedge-fixing type fixing device is likely to come off during manufacturing, storage, transportation, and service because no tensile force is previously introduced into the C material.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and can easily prevent the fixing portion from coming off, so that a PC steel stranded wire can be used as a PC material. It is an object to provide a support structure.

[0006]

The present invention relates to a composite structure of steel pipe and concrete, wherein an unbonded PC is provided in the steel pipe.
In a support structure in which materials are arranged and fixing devices are arranged at both ends of the PC material, the PC material uses a PC steel strand, and the fixing device includes a fixing device for fixing an end portion of the PC material and a fixing device. A support structure comprising: an anchor panel that contacts and supports the other; and a pressing plate that sandwiches the other of the fixing tools in cooperation with the anchor panel. Further, the fixing device of the present invention has a support structure in which a fixing tool is sandwiched between a pressing plate and an anchor board and is integrally fixed with a fixing bolt. Still further, the steel pipe of the present invention is a bent steel pipe, and the PC steel stranded wire inserted into the inside of the bent steel pipe has a column structure in which spacers for holding at predetermined intervals are arranged.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

<A> Presupposed Post Structure FIG. 1 is a side sectional view of the post 1. The present invention is based on the premise that it is a composite structure of a curved steel pipe 2 and concrete C filled in the steel pipe 2, and has a structure in which a plurality of unbonded PC steel strands 5 are arranged in the steel pipe 2. I have. As will be described later, the present invention employs a fixing device.
The use of a C steel strand and the use of a fixing tool of a wedge fixing type are enabled. Hereinafter, each unit will be described.

<B> Steel Pipe The steel pipe 2 is bent and installed to the valley side at the time of installation at the site described later, and is fixed. When a large impact force such as a falling rock or an avalanche acts on the steel pipe 2, a tensile material (PC steel) at the time of deformation of the steel pipe 2 is used. This is for advantageously introducing a tension into the stranded wire 5). (FIG. 4) A convex portion 21 for guiding the fixing device 4 is provided on the entire length of the inner peripheral surface of the steel pipe 2 in the axial direction. (FIG. 2) The shape of the protrusion 21 may be any other shape such as a U-shape.

<C> PC steel stranded wire PC steel stranded wire 5 is a steel material which has been unbonded by a known method such as a sheath made of polyethylene and coated with grease or the like as a rust preventive / lubricating agent.

<D> Spacer The spacer 6 is installed at a predetermined interval from the PC steel strand 5. The shape is an annular shape, the outer diameter of which is slightly smaller than the inner diameter of the steel pipe 2, and a plurality of insertion holes 61 for inserting the PC stranded wire 5 are formed in the circumferential direction at a predetermined pitch.
(FIG. 1) The hole 62 at the center is for passing the concrete C. An anchor plate 42 is provided on the outer peripheral edge of the spacer 6.
A concave portion 22 for guiding the fixing device 4 is provided along a convex portion 21 provided on the inner peripheral surface of the steel pipe 2 in the same manner as the outer peripheral edge. By installing the spacer 6, the spacing between the PC steel strands 5 is maintained in the steel pipe 2 and the concrete C
Can be performed between the fixing device 4 and the spacer 6 and between the spacers 6 and 6.

<E> Concrete Concrete C is filled inside the steel pipe 2 and is filled around the unbonded PC steel strand 5. The hardened concrete C is constrained between the fixing device 4 and the spacers 6 and the spacers 6 and 6 so that only the PC steel strand 5 can slide freely. Therefore, the stress of the fixing device 4 and the spacers 6 and the spacers 6 and 6 acts uniformly, so that the stress of the PC steel strand 5 at the position where the impact load is applied to the column 1 is not excessively broken. It is possible to avoid the PC steel strand 5 from being broken until it breaks.

<F> Fixing Device FIG. 2 is an exploded perspective view of the fixing device 4, and FIG. 3 is a perspective view showing how the fixing device 4 and the steel pipe 2 are attached. The fixing device 4 includes an anchor plate 42 for supporting a fixing device 41 of a wedge fixing type in which the end of the PC steel strand 5 is fixed, a pressing plate 43 for pressing the wedge exposed end of the fixing device 41, The fixing bolt 3 integrally fixes the plate 43. Note that the fixing tool 41 may be a crimp-type grip type. The anchor board 42 is a plate having an annular or arc shape, and through holes 61 are formed at intervals of the PC steel strands 5. Further, a plurality of screw holes 44 through which the fixing bolt 3 is inserted are provided at positions off the insertion holes 61. The pressing plate 43 is an annular or arcuate plate and functions to hold a plurality of fixing tools 41 in common. In the outer peripheral edges of the anchor plate 42 and the pressing plate 43, the concave portion 2 slidable by fitting into the convex portion 21 provided on the inner peripheral surface of the steel pipe 2.
2 are provided. (FIG. 2) The shape of the concave portion 22 is, for example, a U-shape, and the convex portion 21 for guiding the fixing tool 4 provided in the axial direction of the inner peripheral surface of the steel pipe 2.
What is necessary is just to match with a shape.

[0014]

[Action]

<A> Restriction Action by Fixing Device Fixing devices 4 are attached to both ends of the PC steel strand 5, and the unbonded PC steel strand 5 is inserted into the steel pipe 2. After inserting the PC steel strand 5, the steel pipe 2 is filled with concrete C to complete the non-prestressed column 1. The fixing device 4
When the strut 1 is hit by a falling rock or the like, concrete 3
While trying to escape, and reduce the impact load to PC
It transmits to the steel strand 5. As shown in FIG. 3, the fixing device 4
An anchor board 42 and a pressing plate 43 constituting the fixing device 41
And the fixing tool 41 is integrated by tightening the fixing bolts 3, so that there is no fear that the fixing tool 41 will fall off the PC steel stranded wire 5 not only during manufacturing but also during transportation and installation.

<B> Improvement of Deformation Ability of Unbonded PC Steel Strands In a general PC method, when tension is introduced into PC steel strands,
The strength is somewhat stronger. However, since a compressive force is applied by introducing the tension, the deformability is reduced. Therefore, when a large load is applied, the compression side has a disadvantage that the strength is reduced before the tension side, and the crushing occurs earlier, and the strength is rapidly reduced to cause a crack in the steel pipe 2 on the tension side. Since the PC steel stranded wire 5 of the present invention is installed in an unbonded state in which no tension is introduced, the PC steel stranded wire 5 does not receive a compressive force, so that its deformability is improved. However, the tension is not applied to the PC steel wire 5 at all, but the tension is introduced for the first time at this point, since the PC steel wire 5 on the tension side is elongated when the column 1 is deformed. Therefore, the load carrying capacity is almost the same as when the tension is introduced from the beginning, and the same strength can be obtained. That is, the strut 1 of the present invention can exhibit excellent effects in terms of load bearing capacity and deformability.

<C> Restraining action and operability by concrete and spacer The hardened concrete C is supplied to the fixing device 4 and the spacer 6
And, when the impact is applied to the column 1, the load is constrained between the spacers 6, 6, and is uniformly transmitted to the PC stranded wire 5, and is dispersed into an averaged small load. Therefore, the support 1 can be safely reinforced and protected without the stress of the PC steel strand 5 becoming excessive and breaking.

<D> Example of use FIG. 4 is a perspective view of the application to the pillar 1 of the rock fall protection fence. The base of the column 1 is inserted into a hole L provided in the retaining wall K and fixed by an arbitrary method. A protection fence D is installed between the columns 1 and 1 to protect the rocks from entering. A stay S is attached to an intermediate portion of the column 1 and is connected to an anchor A driven into a slope to counter impacts such as falling rocks.

[0019]

Since the present invention has been described above,
The following effects can be obtained. <B> Since the fixing device has a structure in which the fixing device is interposed between the anchor plate and the pressing plate, and is fixed by fixing with the fixing bolt, there is no fear that the fixing device will fall off the PC steel strand. . <B> Since a PC stranded wire can be used as the tensile material, workability and workability are easy even in the case of a bent steel pipe support. <C> Since the projections in the steel pipe and the recesses on the outer edge of the anchor board and spacer serve as guides, respectively, it is easy to insert the PC steel strand into the bent steel pipe support.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a column according to the present invention.

FIG. 2 is an exploded perspective view of the fixing device.

FIG. 3 is a perspective view showing an attachment state of a fixing tool and a steel pipe.

FIG. 4 is a perspective view showing a situation where a support is installed on the site.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E01F 7/04

Claims (3)

(57) [Claims] 1. A composite structure of steel pipe and concrete,
In a column structure in which an unbonded PC material is arranged in a steel pipe and fixing devices are arranged at both ends of the PC material, the PC material uses a PC steel stranded wire, and the fixing device fixes a PC wire end portion. A support structure, comprising: a fixing tool to be fixed; an anchor board that abuts and supports the fixing tool; and a pressing plate that cooperates with the anchor board to hold the other of the fixing tools. 2. The support structure according to claim 1, wherein the fixing device holds the fixing tool between a pressing plate and an anchor board and is integrally fixed with a fixing bolt. 3. The support structure according to claim 1, wherein the steel pipe is a bent steel pipe, and a PC stranded wire inserted into the steel pipe is held at a predetermined interval. A strut structure characterized by the arrangement of