JP2804192B2 - Structure for applying compressive stress to structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for applying a compressive stress to a structure.

[0002]

2. Description of the Related Art For example, a ground anchor method which is widely used for stabilizing a slope of a ground is generally used to cut a portion to be cut of a slope of the ground, which is a first structure, from an upper portion to form a step portion and a cut surface. The anchor hole is formed by drilling an anchor hole with a drilling machine such as a boring machine from the cut surface that becomes the ground surface and going into the ground, inserting a tensile material into the anchor hole and fixing the base end in the ground. To form

[0003] Next, a concrete block, which is a second structure having a through hole through which the tip of the tensile member is inserted at the center, is placed on the cut surface, and the tip of the tensile member is inserted through the through hole to support the base. The tension is applied to the tensile material through the base material, and the ground serving as the first structure, that is, the ground and the block serving as the second structure are firmly fixed to apply compressive stress to the cut ground, thereby stabilizing the slope. Plan.

[0004] The work from the cutting of the slope to the tensioning of the tensile material is performed in order from the upper part to the lower part of the slope.

A method of imparting a compressive stress to a ground by applying tension to a tensile material is disclosed in, for example, Japanese Patent Application Laid-Open No. 51-141440, and as shown in FIG. The tension member c is fixed by hitting a wedge d into the cone a and the tension member c in a state where the cone a and the tension member c are fixed to each other using a tension tool such as a jack.
Is tightened with a nut e screwed on the outer periphery of the block and fixed to the block g as the second structure via the support base f.

[0009] Even in a building, as shown in FIG. 9, a tensile member j is inserted into an anchor hole i formed in a concrete beam h serving as a first structure, and a base end of the tensile member j. (Not shown) is fixed to form an anchor body, and the tip of the tensile member j is inserted into a through hole 1 formed in a concrete column k serving as a second structure, and the tensile member j is inserted through a support base m. Are applied to each other so as to join the beams h and the columns k.

[0007]

In the above prior art, tension of the tension member is obtained while the tension member and the cone are fixed in advance by wedges, and the fixing of the cone to the second structure is also performed by a nut. The work can be easily achieved since the tightening adjustment is performed, and the effect of re-tensioning the tensile material, that is, applying compressive stress to the first structure can be obtained. However, since the contact surface between the second structure and the support pedestal is a flat surface substantially orthogonal to the tension direction of the tension member, the pressing load acting on the second structure due to the tension member tension is in the tension direction,
That is, in order to act only in the thickness direction of the second structure, to sufficiently receive the load and to firmly join the second structure, the thickness of the second structure in the tension direction must be large. The body becomes heavy and requires reinforcement. Therefore, not only does the manufacturing cost of the second structure itself increase, but also a large-sized truck and a large crane are inevitably used for transportation to the construction site, and the construction cost is increased. .

Therefore, an object of the present invention is to reduce the thickness of the second structure in the tension direction by dispersing the pressing force acting on the second structure in the tension direction when compressive stress is applied to the first structure. It is an object of the present invention to provide a structure for applying a compressive stress to a structure, which can reduce the manufacturing cost of the second structure, and can be easily transported and implemented.

[0009]

A structure for applying a compressive stress to a structure according to the present invention, which achieves the above object, becomes an anchor by inserting a tensile member from the surface of the first structure toward the inside of the structure. A second base member, wherein the base end of the tensile member is fixed, and the distal end of the tensile member protruding from the surface of the first structural member is located on the surface of the first structural member.
It is supported by the support pedestal through the through hole formed in the structure,
In a structure in which a tension is applied to a tension member to apply a compressive stress to a first structure and a second structure via a support pedestal, a tapered periphery in which the support pedestal is tapered toward a base end direction of the tension member. And a tapered hole formed in the second structure body and having a through hole fitted with the tapered peripheral surface of the support pedestal.

[0010]

By pressing the tapered peripheral surface of the support base into the tapered hole formed in the second structure, the pressing load acting on the second structure via the support base due to the tension of the tension member is dispersed. The load acting on the second structure in the tension direction is reduced, the size of the second structure receiving the load in the tension direction can be reduced, and the reinforcement can be simplified.
Lighter weight is obtained.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a structure in which a compressive stress applying structure of the present invention is applied to an anchor head structure of a ground anchor in which a first structure is a ground and a second structure is a block. It will be explained by.

FIG. 2 is an explanatory view showing an outline of the ground anchor, and FIG. 1 is an enlarged view of a portion A in FIG. 1 serving as an anchor head.

For stabilization of the slope by the ground anchor, for example, a concrete block 2 as a second structure is positioned on a slope 1a of a ground 1 which is a ground as a ground as a first structure shown in FIG. To form a cutting surface 1b and a cutting step 1c to be a surface. Next, an anchor hole 1d is drilled into the cut surface 1b by a boring machine such as a boring machine so as to face the ground, a tensile material 3 is inserted into the hole 1d, and cement milk is injected under pressure into the anchor hole 1d to be pulled. The base end 3a of the material 3 is fixed in the ground as an anchor body.

Subsequently, the tension member 3 is tensioned using a tensioning tool such as a jack, and the tension member 3 protruding from the cut surface 1b.
Is supported by the block 2 constituting the anchor head.

Next, the structure of the anchor head supporting the distal end 3b of the tension member 3 will be described in detail with reference to FIG.

The concrete block 2 has a substantially cross shape or a rectangular shape, and has a concave portion 2a which opens upward at the center thereof, and a bottom portion 2a 'of the concave portion 2a and a bottom surface 2b which is in contact with the ground surface. A through hole 2c penetrating in the thickness direction of the block 2 is formed between them. Depressed portion 2 of through hole 2c
On the side a, a frustoconical tapered hole 2d tapering toward the bottom surface 2b, that is, toward the base end 3a of the tensile member 3, is formed, and one end of the tapered hole 2d is a bottom 2a 'of the concave portion 2a.
It is open to. Further, a funnel-shaped protection member 4 made of iron is stretched over the inner peripheral surface of the tapered hole portion 2d to protect and reinforce the inner peripheral surface of the tapered hole portion 2d when the shape of the inner peripheral surface is adjusted.

On the inner peripheral surface of the tapered hole portion 2d, a support pedestal 5 to be fitted with a protective material 4 interposed is provided. As shown in a perspective view in FIG. 3, the support pedestal 5 is substantially frustoconical and has a tapered peripheral surface 5a fitted to the inner peripheral surface of the protective member 4, and the tapered peripheral surface 5a is It is covered with a synthetic resin 5e (only a part is shown), for example, a hard rubber or the like so as to be in close contact with. Further, a through hole 5b is formed at the center of the support base 5, and a concave portion 5c for accommodating a cone 6 and a part of a nut 7 described later is formed at an upper portion of the through hole 5b.

On the other hand, the outer periphery of the tensile member 3 has a tip 3 for rust prevention.
b, covered with a synthetic resin tube,
b is a through hole 2c of the block 2 and a through hole 5b of the support base 5.
Through the tension material insertion hole 6b formed in the cone 6 having a threaded portion 6a formed on the outer periphery thereof.
It is fixed by a wedge (not shown) which is driven into the inside.

The cone 6 to which the tension member 3 is fixed is pulled together with the tension member 3 at a position in front of the support pedestal 5 using a tension tool (not shown) such as a jack. The recess 5 of the support pedestal 5 via the mating nut 7
c, so that the cone 6 is fixed.

The lower end of the through hole 5b of the support base 5 is closed by a seal member 8 having a hole 8a through which the tension member 3 is inserted, and grease injected from a grease injection pipe 9 is filled in the through hole 5b. Further, the cone 6 and the like are covered with an oil cap 10 filled with grease to prevent rust on the tip 3b of the tension member 3, the cone 6, the nut 7, and the like. The code 1
Reference numeral 1 denotes a cover that covers the recess 2a of the block 2, protects the tension member 3, the cone 6, the nut 7 and the like from falling rocks, and further prevents rainwater or the like from flowing into the recess 2a.

According to the anchor head structure of the ground anchor configured as described above, the pressing load acting on the block 2 via the support pedestal 5 due to the tension of the tension member 3 is reduced by the tapered peripheral surface 5a of the support pedestal 5. Further, since the tapered hole portion 2d of the block 2 has a predetermined inclination angle with respect to the direction of the base end 3a of the tensile member 3, the taper hole portion 2d is dispersed, and the load acting on the block 2 in the tension direction is reduced. Therefore, the thickness from the bottom 2a 'to the bottom 2b of the concave portion 2a of the block 2 for receiving the load is set to be smaller than that of the conventional case even when securing the bonding force between the ground 1 and the block 2 as in the conventional case. In addition, the size of the tension member 3 and the like protruding into the concave portion 2a by accommodating a part of the nut 7 screwed into the screw portion 6a of the cone 6 in the concave portion 5c of the support base 5 can be reduced. And the depth of the concave portion 2a can be reduced to a small size, the size of the entire block 2 in the tensioning direction can be reduced, and the size and weight of the block 2 can be expected to be reduced.

As shown in FIG. 4, the side L is 800 m.
m, a block 2 'made of coccrete having a concave portion which is upwardly opened at the center in a flat shape having a thickness H of 200 mm.
Is formed, and the diameter of the large diameter portion is 100 mm and the height h ² is 4 so that the upper surface is located at a position where the depth h ^{1 of the} concave portion is 100 mm.
0 mm, the angle α is range concrete support pedestal 5 which forms a 30 ° and 10 ° of the perpendicular 'fitted and placed the test anchor head T ₁ on the support base, the support base 5' upward As a result of applying a load P from Table ₁ , as a result of measuring the average breaking load of the test anchor head T1 having the angle α of 30 ° as shown in Table ₁ , the result was 12110 kg, and the angle α was 10 °.
The anchor for the test head T ₁ is a 13975Kg,
The angle between the peripheral surface of the tapered peripheral surface 5a and the peripheral surface of the tapered hole 2d and the tensioning direction is preferably in the range of 4 ° to 45 °.

[0023]

[Table 1]

In the above embodiment, an example in which the support pedestal 5, the cone 6, and the nut 7 are constituted by two separate parts has been described. However, as shown in FIG.
By forming the screw portion 5d to be screwed to the screw portion 6a of the cone 6 formed on the inner periphery of c and eliminating the nut 7, it is also possible to simplify the structure and reduce the number of parts. It is also possible to form the tapered hole 2d formed in the block 2 into a truncated pyramid shape and the tapered peripheral surface of the support pedestal into a truncated pyramid shape that fits into the tapered hole portion 2d. The block is not limited to a concrete block, but may be applied to a structure such as a wall surface made of concrete or a steel plate.

Next, another embodiment of the structure for applying compressive stress to a structure according to the present invention is applied to a building in which the first structure is a concrete beam and the second structure is a concrete column supporting the beam. An example will be described with reference to FIG.

An anchor hole 11a is formed in the beam 11 of the building serving as the first structure. A tensile member 12 is inserted into the hole 11a, and a base end (not shown) of the tensile member 12 is inserted into the anchor hole 11a. It is fixed in the concrete beam 11 as an anchor body.

The end 11b of the beam 11 thus formed
Is fitted into the step 13a formed on the concrete pillar 13 serving as the second structure, the tension member 12 is tightened using a tensioning tool, and the tip 12a of the tension member 12 projecting from the beam 11 is fixed to the column 13. Let it.

Pillar 13 supporting tip 12a of tensile member 12
Is formed with a concave portion 13b which opens in the opposite direction to the concave portion 13a, and the concave portion 13b and the step portion 13a are communicated with each other by a through hole 13c.

On the side of the recess 13b of the through hole 13c, there is formed a tapered hole 13d of a truncated cone or truncated pyramid tapering toward the beam 11, that is, toward the base end of the tensile member 12. Has an opening at the bottom 13b 'of the recess 13b. Further, a protective material 14 is stretched on the inner peripheral surface of the tapered hole portion 13d, and protection and reinforcement are achieved while the shape of the inner peripheral surface of the tapered hole portion 13d is adjusted.

A protective material 14 is provided on the inner peripheral surface of the tapered hole 13d.
The support pedestal 15 that fits with the interposition of the support base 15 is provided. A through hole 15a is formed at the center of the support base 15, and a cone 16 and a nut 1 are formed at the end of the through hole 15a.
A recess 15b for accommodating a part of 7 is formed.

On the other hand, the tip 12a of the tension member 12 penetrates through the through hole 13c of the column 13 and the through hole 15a of the support base 15, and is inserted into a tension member insertion hole (not shown) formed in the cone 16 to insert the tension member. It is secured by a wedge (not shown) driven into the hole.

The cone 16 to which the tension member 12 is fixed is pulled together with the tension member 12 by a tensioning tool at a position in front of the support pedestal 15 and at a required tension position via a nut 17 screwed to the screw portion 16a. The cone 16 is fixed by contacting the concave portion 15b.

The beam 11 of the through hole 15a of the support base 15
The side end is closed by a seal member 18 having a hole 18a through which the tensile material 12 is inserted, and grease injected from a grease injection pipe 19 is filled in the through hole 13c, and further, the cone 16 and the like are filled with grease. Cover with a cap 20, a tip 12a of a tension member 12, a cone 16 and a nut 1.
Rust prevention such as 7 is achieved. Further, if necessary, the concave portion 13b
Is covered with a lid 21 attached with bolts (not shown) or the like.

According to the joint structure of the beam 11 and the column 13 configured as described above, a compressive stress is applied to the beam 11 in accordance with the tension of the tension member 12, the rigidity is improved, and the size of the beam 11 is reduced. Further, the pressing load in the tension direction acting on the column 13 via the support pedestal 15 is dispersed by the tapered peripheral surface 15 c of the support pedestal 15 and the tapered hole portion 13 d of the column 13. Therefore, it is possible to reduce the size from the bottom of the recessed portion 13a of the column 13 receiving the load to the step 13a as compared with the conventional one and to simplify the reinforcement, and to reduce the weight of the column 13 serving as the second structure. Can be achieved.

In the above description, the base end of the tension member 12 is fixed as an anchor body in the anchor hole 11a formed in the concrete beam 11, but the anchor hole 11a is formed so as to penetrate the beam 11 over the entire length. Anchor hole 1 penetrated
It is also possible to insert the tension member 12 through 1a and fix the base end to the other pillar.

In the above description, the case where the structure for applying compressive stress of the structure according to the present invention is applied to the anchor head structure of the ground anchor and the joint structure of the beams and columns of the building has been described. The present invention can be widely used for connecting structures of structures in other industrial fields such as connecting.

Next, still another embodiment of the structure for applying a compressive stress to a structure according to the present invention will be described with reference to FIG.

An anchor hole 21a is formed at one end of, for example, the beam 21 serving as a structural body. A tensile member 22 is inserted into the hole 21a, and the tensile member 22 is inserted into the anchor hole 21a.
Is fixed in the concrete beam 21 as an anchor body.

A concave portion 21c which opens outward is formed at the end 21b of the beam 21 where the anchor hole 21a opens, and the concave portion 21c communicates with the anchor hole 21a. A tension member 22 is provided on the side of the recess 21c of the anchor hole 21a.
A tapered hole 21d of a truncated conical shape or a truncated pyramid shape tapering toward the base end direction is formed, and one end of the tapered hole 21d is opened at the bottom 21c 'with the recess 21c.
Further, a protective material 23 is stretched on the inner peripheral surface of the tapered hole portion 21d, and protection and reinforcement are achieved while adjusting the shape of the inner peripheral surface of the tapered hole portion 21d.

The protective material 23 is provided on the inner peripheral surface of the tapered hole 21d.
A support pedestal 24 having a tapered peripheral surface 24c that fits through the support base 24 is provided. A through-hole 24a is formed at the center of the support pedestal 24, and a cone 2 is formed at an end of the through-hole 24a.
A recess 24b for accommodating a part of the nut 5 and the nut 26 is formed.

On the other hand, the tip 22a of the tensile member 22 is
Is inserted through a tension member insertion hole (not shown) formed in the cone 25 and is fixed by a wedge (not shown) driven into the tension member insertion hole.

The cone 25 to which the tension member 22 is fixed is pulled together with the tension member 22 at a position in front of the support pedestal 24 by a tensioning tool, and at the required tension position, the nut 25 is screwed into the screw portion 25a. The cone 25 is fixed by contacting the concave portion 24b.

The base end side of the through hole 24a of the support pedestal 24 is closed by a sealing member 27 having a hole 27a through which the tensile material 22 is inserted. Is covered with an oil cap 28 filled with grease, and the tip 22a of the tension member 22 and the cone 2
5 and nuts 26 are prevented from rusting. Further recess 2
1c is covered with a lid 29 attached with bolts (not shown) or the like as necessary.

According to the structure for applying the compressive stress of the structure having such a structure, the compressive stress is applied to the beam 21 in accordance with the tension of the tensile member 22, and the rigidity is improved. Therefore, the thickness of the beam 21 can be reduced, and the weight can be reduced.
Further, the pressing load in the tension direction acting on the beam via the support pedestal 24 is dispersed by the tapered peripheral surface 24 c of the support pedestal 24 and the tapered hole 21 d of the beam 21. Therefore, the reinforcement can be simplified without the load being concentrated on the end of the beam 21.

In the above description, the base end of the tensile member 22 is fixed in the anchor hole 21a as an anchor body, but the anchor hole 21a is formed so as to penetrate the entire length of the beam, and the base end of the tensile member 22 is fixed. It is also possible to fix to the end of the anchor hole opened at the other end of the beam.

The present invention is not limited to beams, and can be widely used, for example, for applying compressive stress to bridge girders or other structures.

[0047]

According to the structure for imparting compressive stress of a structure according to the present invention described above, the tapered peripheral surface tapering in the direction of tension of the support base is fitted into the tapered hole formed in the structure. As a result, the pressing load acting on the structure through the support pedestal caused by the tension member tension is dispersed, the load acting on the structure in the tension direction is reduced, and the size of the structure receiving the load is reduced and reinforced. It is possible to reduce the weight of the structure, reduce the production cost of the structure, and effectively carry and transport the structure to the construction site, thereby obtaining a significant cost reduction.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of an anchor head of a ground anchor for explaining an embodiment of a compressive stress applying structure of a structure according to the present invention.

FIG. 2 is also a schematic explanatory diagram of a ground anchor for explaining the present embodiment.

FIG. 3 is an explanatory perspective view of a support base used in the present embodiment.

FIG. 4 is an explanatory diagram of an outline of a test for measuring a breaking load of an anchor head in the embodiment.

FIG. 5 is an explanatory perspective view of another embodiment of a support base used in the present embodiment.

FIG. 6 is a cross-sectional view of a principal part illustrating a joint structure of beams and columns of a building showing another embodiment of the structure for applying compressive stress to a structure according to the present invention.

FIG. 7 is a cross-sectional view of a main part of a structural body for explaining still another embodiment of the structural body compressive stress applying structure according to the present invention.

FIG. 8 is a sectional view of an essential part for explaining a conventional ground anchor head structure.

FIG. 9 is a cross-sectional view of a main part illustrating a connection structure between a beam and a column in a conventional building.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground (1st structure) 2 Block 2c Through-hole 2d Taper hole 3 Tensile material 3a Base end 3b Tip 5 Support base 5a Peripheral surface 5c Synthetic resin 6 Cone 11 Beam (1st structure) 12 Tensile material 13 Column ( 2nd structure) 13c through-hole 13d taper hole 15 support pedestal 15c peripheral surface 21 beam (structure) 21a anchor hole 21d taper hole 22 tension member 22a tip 24 support pedestal 24c tapered peripheral surface

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Nakai 3-7-11 Kiba, Koto-ku, Tokyo Inside Toa Grout Industry Co., Ltd. (72) Inventor Masaki Shiomi 4-13-5 Tamazo, Narita-shi, Chiba (56 References: JP-B-48-11298 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 5/80

Claims (10)

(57) [Claims] 1. A tensile member is inserted from the surface of the first structure toward the inside of the structure to fix a base end of a tensile member serving as an anchor body. The first structure and the second structure are supported by the support pedestal through the through-hole formed in the second structure located on the surface of the first structure, apply tension to the tensile member, and via the support pedestal. The support pedestal has a tapered peripheral surface that tapers toward the tensile material base end, and a through hole formed in the second structure has a tapered peripheral surface of the support pedestal. A compressive stress applying structure for a structural body, characterized in that the structure has a tapered hole portion that fits into the structure. 2. The structure according to claim 1, wherein the tapered peripheral surface of the support pedestal is frustoconical, and the tapered hole formed in the second structure is a frustoconical tapered hole. 3. The structure according to claim 1, wherein the tapered peripheral surface of the support pedestal has a truncated pyramid shape, and the tapered hole formed in the second structure is a truncated pyramid tapered hole. 4. The compressive stress of the structure according to claim 1, wherein at least one of the tapered peripheral surface of the support base and the tapered hole formed in the second structure is covered with a synthetic resin. Grant structure. 5. The tension member according to claim 1, wherein the tip of the tension member is connected to the cone, and is supported by the support base via the cone.
A compressive stress applying structure for the structure according to any one of the first to third aspects. 6. The structure according to claim 5, wherein at least a part of the cone is accommodated in a recess formed in the support base. 7. The angle between the tapered peripheral surface of the support pedestal and the tapered hole of the through hole formed in the second structure and the tensioning direction of the tensile member is in the range of 4 ° to 45 °. 6. A compressive stress imparting structure of the structure according to one of 6. 8. The structure according to claim 1, wherein the first structure is ground, and the second structure is a block placed on the ground surface. 9. A tension member is inserted from one end of the structure into an anchor hole opening toward the inside of the structure to fix a tension member base end serving as an anchor body, and a distal end of the tension member protruding from the structure. Is supported by a support pedestal located on the surface of the structure,
In a structure in which tension is applied to a tensile member to apply a compressive stress to a structure through a support pedestal, the support pedestal has a tapered peripheral surface that tapers toward a tensile material proximal direction, and A structure for applying a compressive stress to a structure, wherein the formed anchor hole has a tapered hole portion fitted to the tapered peripheral surface of the support base. 10. The structure according to claim 9, wherein the anchor hole is a through hole reaching the other end of the structure, and the tensile material base end is fixed to an end of the anchor hole that opens through the anchor hole and opens at the other end. Structure for applying compressive stress to the body.