JP3706382B2 - Supporting stress dispersion member, tension anchor, and prestressed concrete - Google Patents

Description

  The present invention relates to a tension fixing tool attached to both ends of a PC steel material of prestressed concrete.

  FIG. 3 is a sectional view showing a first example of a conventional tension fixing device, and FIG. 4 is a sectional view showing a second example of the conventional tension fixing device.

  In general, prestressed concrete is frequently used for structural materials that receive bending loads such as bridge girders and sleepers. In this kind of prestressed concrete, as shown in FIGS. 3 (a) and 4 (a), the tension fixing device 1 is attached to both ends of the PC steel material 8 disposed on the tensile side of the concrete 7, respectively. Prestress is applied to the concrete 7 by generating tension on the PC steel 8 by the tension fixing tool 1.

Conventionally, as the tension fixing device 1, as shown in FIG. 3 (a), a grid-like grid line 5 as a supporting stress dispersing member is engaged with a PC steel material 8, and a nut 2 and a supporting plate 3 are attached thereto. The combination was used (for example, refer patent document 1). Further, as shown in FIG. 4A, a spiral guide 6 is fixed to a cylindrical guide 4 through which the PC steel material 8 passes as a supporting stress dispersion member, and a nut 2 is combined therewith. (For example, refer to Patent Document 2).
JP 2002-97745 A (paragraph [0013] column, FIGS. 1 to 3) JP 2002-97745 A (paragraph [0021] column, FIG. 7)

  However, these conventional tension fixing devices 1 have the following disadvantages.

  First, in the tension fixing device 1 (see FIG. 3) using the grid reinforcement 5, usually, a grid-like grid is formed by welding two pieces of reinforcing bars bent in a wave shape for each tension fixing device 1 and welding the contacts. Muscle 5 must be made. Therefore, the production of the grid stripe 5 is troublesome and takes time and effort. In addition, in order to obtain an effective bearing stress distribution function, it is necessary to set the installation depth L1 of the grid reinforcement 5 to a constant value. In practice, however, the grid reinforcement 5 is in the axial direction of the PC steel material 8. 3 or may be inclined with respect to a plane perpendicular to the axis of the PC steel material 8, thereby reducing the support stress distribution function by the grid bars 5.

  On the other hand, in the tension fixing device 1 using the spiral muscle 6 (see FIG. 4), the length L2 of the spiral muscle 6 can be shortened to a certain length or less because of the necessity of expressing a desired support stress distribution function. Can not. For this reason, the spiral streaks 6 are bulky, and accordingly, the storage fee and the transportation cost of the spiral streaks 6 are increased. Further, as shown in FIG. 4B, the spiral muscle 6 is lowered from a predetermined position with respect to the guide 4, or is inclined with respect to the tube core of the guide 4 as shown in FIG. 4C. There is a possibility that the support stress distribution function by the spiral muscle 6 is lowered.

  In view of such circumstances, the present invention is easy to manufacture, always fully exerts the support stress distribution function, and can provide a compact support stress distribution member that can contribute to the reduction of storage fees and transportation costs. The object is to provide tools and prestressed concrete.

The invention according to claim 1 is manufactured in the shape of a plane symmetrical with respect to the thickness direction, and has a shape corresponding to the shape of the guide for inserting a cylindrical guide through which the PC steel material is inserted into the central portion. guide insertion hole is formed Rutotomoni, a plurality of through holes around the guide insertion holes are formed at intervals in the circumferential direction, the thickness of the edge portion of the periphery of the guide insertion hole of the other cut meats It is a bearing stress distribution member which is larger than the thickness and can be locked to a jaw portion formed on the outer peripheral portion of the guide at an edge portion where the wall thickness is large.
The invention according to claim 2 is the bearing stress distribution member according to claim 1, characterized in that a rib is provided on an outer periphery of an edge portion around the guide insertion hole.
The invention according to claim 3 is the bearing stress distribution member according to claim 1 or 2 , except that the thickness of the outer peripheral edge portion excludes the peripheral edge portion of the inner periphery of the guide insertion hole. It is characterized by being larger than the thickness of the part.
The invention according to claim 4 is the bearing stress distribution member according to claim 3 , wherein a through hole is formed in an intermediate portion between the peripheral edge portion of the guide insertion hole and the peripheral edge portion. Features.
The invention according to claim 5 includes the bearing stress distribution member according to any one of claims 1 to 4 and a cylindrical guide through which the guide steel insertion hole is inserted. It is a characteristic tension anchor.
According to a sixth aspect of the present invention, in the tension fixing device according to the fifth aspect , the supporting stress distribution member is locked to a jaw portion formed on an outer peripheral portion of the guide.
According to a seventh aspect of the present invention, in the tension fixing device according to the sixth aspect of the present invention, the tension fixing tool is engaged with a jaw portion of the guide at an edge portion around the guide insertion hole.
The invention according to claim 8 is a prestressed concrete in which the tension fixing tool according to any one of claims 5 to 7 is attached to both ends of the PC steel material disposed on the tension side of the concrete. is there.
The invention according to claim 9 is the prestressed concrete according to claim 8 , wherein a cage bar is attached to the outer periphery of the guide of the tension fixing tool.

  According to the present invention, since the guide insertion hole is formed in the flat grid rod, the support stress distribution member can be easily manufactured, and the storage fee and the transportation cost can be reduced.

  Further, when ribs are provided on the grid rod, the surface area of the support stress distribution member is increased, and the support stress distribution function is further improved.

  Further, if the through holes are formed in the grid rod, the support stress distribution member is reduced in weight, and the storage fee and the transportation cost are further reduced.

  Further, if the support stress distribution member is locked to the jaw portion of the guide, the installation depth of the support stress distribution member is always constant, and the support stress distribution function is fully exhibited.

  In addition, when a cage wire is attached to the outer periphery of the guide of the tension fixing tool, the concrete near the tension fixing tool is reinforced, and the bending strength of the prestressed concrete is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a cross-sectional view showing an embodiment of a tension fixing device according to the present invention, FIG. 2 is a view showing a supporting stress dispersion member of the tension fixing device shown in FIG. 1, and (a) is a front view thereof. (B) is the right side view.

  As shown in FIG. 1, the prestressed concrete has concrete 7, and a PC steel material 8 is disposed on the tensile side of the concrete 7. As this PC steel material 8, arbitrary high-tensile steel (for example, PC steel bar, PC steel wire, PC steel strand, etc.) can be used. Further, tension fixing tools 1 are attached to both ends of the PC steel material 8, and each tension fixing tool 1 includes a fixing block 9, a cylindrical guide 4 made of carbon steel, and a bearing stress made of carbon steel. The dispersion member 10 is constituted.

  Here, the fixing block 9 is configured by combining a female cone and a male cone, and is attached to an end portion of the PC steel material 8.

  The guide 4 is fitted to the PC steel 8 inside the fixing block 9. The guide 4 has a steel material insertion hole 4a formed in the center portion in the axial direction and a jaw portion 4b formed in the outer peripheral portion.

  Further, the supporting stress distribution member 10 is locked to the jaw portion 4 b of the guide 4. As shown in FIG. 2, the support stress distribution member 10 has a rectangular flat plate-shaped grid rod 10a, and a circular guide insertion hole 10b is formed at the center of the grid rod 10a. In addition, a plurality of (16 in FIG. 2) ribs 10c project from the periphery of the grid rod 10a on both the front and back sides, and a plurality (eight in FIG. 2) of through holes 10d are provided. It has been drilled.

  Further, as shown in FIG. 1, a cage line 12 is attached to the outer periphery of the guide 4 of each tension fixing device 1.

  As described above, the supporting stress distribution member 10 has a simple structure in which the guide insertion hole 10b and the like are formed in the grid rod 10a, and thus is easier to manufacture than the conventional grid line 5 (see FIG. 3). .

  In addition, since the supporting stress dispersion member 10 is a thin plate-like member, it is extremely compact as compared with the conventional spiral muscle 6. As a result, the storage fee and the transportation cost of the bearing stress distribution member 10 are greatly reduced.

  Further, since the supporting stress distribution member 10 is locked to the jaw portion 4 b of the guide 4, it is positioned at a fixed position with respect to the end surface of the guide 4 and eventually the concrete 7. For this reason, the installation depth L1 of the support stress distribution member 10 is always constant, and the support stress distribution function is fully exhibited.

  Further, since the ribs 10c protrude from the grid rod 10a, the surface area of the support stress distribution member 10 increases, and the support stress distribution function is further improved.

  Further, since the through-hole 10d is formed in the grid rod 10a, the support stress distribution member 10 is reduced in weight, and its storage fee and transportation cost are further reduced.

  Further, since the cage bars 12 are attached to the outer periphery of the guide 4 of the tension fixing tool 1, the concrete 7 near the tension fixing tool 1 is reinforced, and the bending strength of the prestressed concrete is improved.

  In the above-described embodiment, the supporting stress distribution member 10 including the rectangular flat plate-shaped grid rod 10a has been described. However, the shape of the grid rod 10a is not limited to the rectangular flat plate shape, and may be a polygonal flat plate shape or a circular shape. It may be flat.

  Moreover, the manufacturing method of the bearing stress dispersion | distribution member 10 may be what, for example, the bearing stress dispersion | distribution member 10 can be manufactured by casting or forging.

  Further, the material of the supporting stress distribution member 10 is not necessarily carbon steel, and various fiber reinforced composite materials (for example, fiber reinforced plastic, fiber reinforced alloy, etc.) can be substituted.

It is sectional drawing which shows one Embodiment of the tension fixing tool which concerns on this invention. It is a figure which shows the bearing stress dispersion | distribution member of the tension fixing tool shown in FIG. 1, Comprising: (a) is the front view, (b) is the right view. It is sectional drawing which shows the 1st example of the conventional tension fixing tool. It is sectional drawing which shows the 2nd example of the conventional tension fixing tool.

Explanation of symbols

1 …… Tension fixing device 2 …… Nut 3 …… Supporting plate 4 …… Guide 4a …… Steel insertion hole 4b …… Jaw portion 5 …… Grid reinforcement 6 …… Spiral reinforcement 7 …… Concrete 8 …… PC steel 9 …… Fixing block 10 …… Supporting stress dispersion member 10a …… Grid rod 10b …… Guide insertion hole 10c …… Rib 10d …… Through hole 12 …… Cage L1 …… Installation depth of the supporting stress dispersion member L2 …… Spiral muscle length

Claims (9)

Is manufactured in the thickness direction to the plane symmetric flat, in the center, a cylindrical guide PC steel is inserted is for inserting a guide insertion hole shape corresponding to the shape of the guide is formed Rutotomoni A plurality of through holes are formed around the guide insertion hole at intervals in the circumferential direction, and the thickness of the edge portion around the guide insertion hole is larger than the thickness of the other portion. A supporting stress distribution member characterized in that it can be locked to a jaw portion formed on the outer peripheral portion of the guide at a large edge portion.   The bearing stress distribution member according to claim 1, wherein a rib is provided on an outer periphery of an edge portion around the guide insertion hole. 3. The support stress distribution according to claim 1, wherein a thickness of an outer peripheral edge portion is larger than a thickness of an inner peripheral portion thereof excluding the peripheral edge portion of the guide insertion hole. Element. The supporting stress distribution member according to claim 3 , wherein a through hole is formed in an intermediate portion between an edge portion around the guide insertion hole and an edge portion of the outer periphery. A tension fixing tool comprising: the supporting stress distribution member according to any one of claims 1 to 4 ; and a cylindrical guide through which the guide steel insertion hole is inserted. The tension fixing tool according to claim 5 , wherein the support stress distribution member is locked to a jaw portion formed on an outer peripheral portion of the guide. The tension fixing device according to claim 6 , wherein the tension fixing tool is engaged with a jaw portion of the guide at an edge portion around the guide insertion hole. A prestressed concrete in which the tension fixing tool according to any one of claims 5 to 7 is attached to both ends of a PC steel material disposed on a tensile side of the concrete. The prestressed concrete according to claim 8 , wherein a cage line is attached to an outer periphery of the guide of the tension fixing tool.

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