JP3048721B2 - 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 driving a wedge d into the cone a and the tension member c in a state where the cone a is fixed to the tension member c using a tensioning tool such as a jack.
Is tightened with a nut e screwed to the outer periphery of the block and fixed to the block g as the second structure via the support member f.

Further, even in a building, a tensile member j is inserted into an anchor hole i formed in a concrete beam h serving as a first structure as shown in FIG. (Not shown) to form an anchor body,
Is inserted into a through hole 1 formed in a concrete column k serving as a second structure, and tension is applied to a tensile member j via a support member m to fix the beam h and the column 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 because the tightening adjustment is performed, and the tension of the tension member, that is, the first
This has an effect that a compressive stress can be applied to the structure. However, since the contact surface between the second structure and the support member has a flat shape 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 reduced. Acts only in the thickness direction of the second structure, the thickness of the second structure must be large in order to sufficiently receive the load and firmly fix the second structure, so that the second structure has a large weight, In addition, reinforcement is required. Further, since the second structure and the support member are separately configured, the number of components is increased, and the handling thereof is complicated, which not only increases the manufacturing cost, but also increases the transportation cost to the construction site. There are problems such as the necessity of using a large crane or the like for the enforcement, leading to an increase in the enforcement cost.

Accordingly, an object of the present invention is to reduce the size of the second structure by dispersing the pressing load acting in the tension direction of the second structure when compressive stress is applied to the first structure. Another object of the present invention is to provide a compressive stress applying structure for a structure that can reduce the number of components, reduce manufacturing costs, 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 structure is located on the surface of the first structure
It is supported by the support member through the through hole formed in the structure,
In a structure in which tension is applied to the tensile member to apply compressive stress to the first structure and the second structure via the support member, the support member has a tapered shape tapering toward the proximal end of the tensile member. Thus, the second structure is buried integrally with the second structure.

[0010]

The supporting member is formed in a tapered shape tapering toward the tensile member proximal direction and is embedded integrally in the second structure, so that the pressing load acting on the supporting member in the tensile member proximal direction is reduced. The light is dispersed by the joint surface between the support member and the second structure and transmitted to the second structure. Therefore, the size of the second structure in the tension direction can be reduced, the weight can be reduced, and since the support member and the second structure are integrally formed, the number of components is reduced, and the manufacturing cost is reduced. Reduction, and furthermore, easy handling of transportation and enforcement.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a structure in which a compressive stress applying structure of a structure according to 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. explain.

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.

The slope stabilization by the ground anchor
For example, a concrete block 2 as a second structure is cut out on a slope 1a to be formed on a ground 1 as a ground as a first structure, and a cut surface 1b as a surface.
And a cutting stage 1c. 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 block 2 made of concrete has a substantially cross shape or a rectangular shape, and a concave portion 2a which opens upward is formed at the upper center portion thereof, and a bottom portion 2a 'of the concave portion 2a.
A through-hole 2c penetrating in the thickness direction of the block 2 is formed between the base 2 and the bottom surface 2b in contact with the ground surface.

The through-hole 2c has a frusto-conical tapered hole 2d that tapers from the recess 2a toward the bottom surface 2b, that is, toward the base end 3a of the tensile member 3, and is formed into a tapered hole 2d.
Has an opening at the bottom 2a 'of the recess 2a.

A support member 4 is provided on the inner surface of the tapered hole 2d.
Are provided integrally with the block 2. Support member 4
Is made of a metal, resin, high-hardness resin concrete, concrete reinforced with short fibers or a metal reinforcing material or the like. As shown, it has a tapered peripheral surface 4a, and further has a through hole 4b in the center,
In the upper part of the through hole 4b, a concave portion 4c for accommodating a cone 5 and a part of the nut 6 described later is formed. The support member 4 configured in this manner is a concrete black 2
Embedded in the block 2 when manufacturing the
Is integrated with the block 2 by curing.

On the other hand, the outer periphery of the tensile member 3 is covered with a synthetic resin tube except for the tip 3b for rust prevention, and the tip 3b is formed with the through hole 2c of the block 2 and the through hole 4 of the support member 4.
b through the tension material insertion hole 5b formed in the cone 5 having a threaded portion 5a formed on the outer periphery thereof.
It is fixed by a wedge (not shown) hammered into b.

The cone 5 to which the tension member 3 is fixed is pulled together with the tension member 3 using a tensioning tool (not shown) such as a jack at a position in front of the support member 4, and the screw portion 5 is fixed at a predetermined position.
The nut 5 is pressed into contact with the concave portion 4 c of the support member 4 via the nut 6, and is fixed to the ground surface of the block 2 via the fixing of the cone 5 and the support member 4.

The lower end of the through hole 4b of the support member 4 is closed by a seal member 7 having a hole 7a through which the tensile material 3 is inserted, and grease injected from a grease injection pipe 8 is filled in the through hole 5b. Further, the cone 5 and the like are covered with an oil cap 9 filled with grease to prevent rust on the tip 3b of the tension member 3, the cone 5, the nut 6, and the like. Reference numeral 10
Is a cover that covers the concave portion 2a of the block 2, protects the tension member 3, the cone 5, the nut 6, and the like from falling rocks and the like, and prevents rainwater or the like from flowing into the concave portion 2a.

According to the anchor head structure of the ground anchor configured as described above, the pressing load in the tension direction acting on the block 2 via the support member 4 accompanying the tension of the tension member 3 is reduced by the taper of the support member 4. Peripheral surface 4a and block 2
Since the tapered hole portion 2d has an inclination angle with respect to the direction of the base end 3a of the tensile member 3, it is dispersed. 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 reinforcement can be reduced, and the weight of the block 2 can be reduced. Further, by accommodating a part of the nut 6 screwed into the screw portion 5a of the cone 5 in the concave portion 4c of the support member 4, the dimensions of the tension member 3, the cone 5 and the like protruding into the concave portion 2a become small, and the concave portion 3a Can be configured to have a small depth, and the size and weight of the block 2 can be expected to be further reduced. Since the block 2 and the support member 4 are integrated, simplification of handling and implementation can be obtained.

As shown schematically in FIG. 4, one side L is 800
diameter to thickness H in mm is in the plate-shaped 200 mm, and the depth h ¹ of the concrete blocks 2 'and recesses in the central portion upward with a recess which opens to position the upper surface at the position of 100mm height section diameter at 100 mm h ² 4
0 mm, perpendicular and the angle α are plurality create a test anchor head T ₁ which is integrally connected to the frusto-conical resin concrete made support member 4 'forming a 30 °, the test anchor head T ₁ is placed on the support table, the upper given given the load P from the support member 4 'and the measurement results of the average breaking load of the test anchor head T _1, the value was 12110Kg.

On the other hand, as shown in FIG.
In thickness H is plate-shaped 200 mm, the test anchor head T ₂ of the manufactured concrete creates plurality having a hole diameter D is the depth h ¹ is 100mm in 100mm in its central part, the same supporting bench It was placed, and applying a load P from above into the hole bottom, the value was 10830kg results of measuring the average breaking load of the test anchor head T _2.

Therefore, the anchor head in which the conical support member 4 is provided integrally with the block 2 can withstand a high breaking load, that is, the thickness dimension from the bottom 2a 'to the bottom 2b of the recess 2a of the block 2. It is clear that it is possible to set the size smaller than before and to reduce the reinforcement.

Further, by the method shown in FIG.
Is a flat plate having a thickness of 800 mm and a thickness H of 200 mm, a concrete block 2 ′ having a concave portion that opens upward in the center, and a large-diameter portion diameter such that the upper surface is located at a position where the depth h ^{1 of the} concave portion is 100 mm. Is 100 mm in height h ² is 40
The average fracture load of the test anchor head, which was integrally connected to a resin-concrete support member 4 'having a truncated cone shape having an angle α of 10 ° with respect to the perpendicular, was 1395 kg. Is preferably in the range of 4 ° to 45 °. Table 1 shows that the angle α was 10 ° and 3 °.
It is a fracture load measurement result of the test anchor head of 0 degree.

[0027]

[Table 1]

In the above embodiment, an example was described in which the support member 4, the cone 5, and the nut 6 were constituted by two separate components. However, as shown in FIG.
By forming a screw portion 4d to be screwed to the screw portion 5a of the cone 5 formed on the inner circumference of c and eliminating the nut 6, it is also possible to simplify the structure and reduce the number of parts.

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.

The beam 11 of the building as the first structural body has an anchor hole 11a, a tensile member 12 is inserted into the hole 11a, and the base end (not shown) of the tensile member 12 is used as an anchor body. Fix inside.

The end 11b of the beam 11 thus formed
Is fitted and positioned in 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.

Column 13 for supporting tip 12a of tensile member 12
Is formed with a recess 13b that opens in the opposite direction to the recess 13a, and a through hole 13c is formed between the recess 13b and the step 13a.

The through hole 13c is formed with a truncated conical or truncated pyramid-shaped tapered hole 13d which is tapered from the recessed portion 13b toward the beam 11, that is, toward the base end of the tensile member. One end of the tapered hole 13d is formed. Is open at the bottom 13b 'of the recess 13b.

The support member 1 is provided on the inner surface of the tapered hole 13d.
4 is provided integrally with the pillar 13. The support member 14 is made of, for example, resin concrete having a higher strength than the column 13, has a tapered peripheral surface 14 a, and further has a through hole 14 b formed in the center portion, and a through hole 14 b is formed on the concave portion 13 b side of the through hole 14 b. Recess 1 in which cone 15 and a part of nut 16 are accommodated
4c is formed. The support member 14 is formed in advance,
When manufacturing the concrete pillar 13, it is integrated with the pillar 13 by embedding.

On the other hand, the tip 12a of the tension member 12 passes through the through hole 13c of the column 13 and the through hole 14b of the support member 14, and is inserted into a tension member insertion hole (not shown) formed in the cone 15. It is fixed by a wedge (not shown) driven into the tensile material insertion hole.

The cone 15 to which the tension member 12 is fixed is pulled together with the tension member 12 by a tensioning tool, and presses against the concave portion 14c of the support member 14 at a predetermined tension position via a nut 16 screwed into the screw portion 15a. The fixing of the cone 15 is achieved.

The beam 11 of the through hole 14b of the support member 14
The side end is closed by a sealing member 17 having a hole 17a through which the tensile material 12 is inserted, grease injected from a grease injection pipe 18 is filled in the through hole 14b, and further, the cone 16 and the like are filled with grease. Cover with oil cap 19, tip 12a of tension member 12, cone 15, nut 16
Rust prevention. Reference numeral 20 denotes a lid that covers the recess 13b as necessary.

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 and the rigidity is improved. Is distributed and reduced by the tapered peripheral surface 13 d of the support member 14.

Therefore, the concave portion 1 of the column 13 capable of receiving the load
The thickness from the bottom 13b 'to the step 13a of the base 3b can be reduced to a smaller size than in the prior art, and the reinforcement can be simplified.

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

In the above description, the case where the structure for imparting 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 between the beam and the column of the building has been described. It can be widely used for the connection structure of structures in other industrial fields such as the connection of

Next, still another embodiment of the compressive stress applying structure for 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 a base end (not shown) of the tensile member 22 is inserted into the anchor hole 21a. Is fixed in the concrete beam 21 as an anchor body.

A recess 21c opening outward is formed at the end 21b of the beam 21 where the anchor hole 21a opens, and the recess 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 tapered toward the base end direction is formed, and one end of the tapered hole 21d is opened at the bottom 21c 'of the recess 21c. Further, a support member 23 having a tapered peripheral surface 23a is formed integrally with the beam 21 on the inner peripheral surface of the tapered hole 2d. A through hole 23b is formed in the center of the support member 23, and a concave portion 23c for accommodating a part of the cone and the nut 26 is formed at an end of the through hole 23b.

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

The cone 25 to which the tension member 22 is fixed is pulled together with the tension member 22 by a tensioning tool at a position in front of the support member 23, and the support member 23 is interposed at a required tension position with a nut 26 screwed into the screw portion 25a. The fixing of the cone 25 is achieved by contacting the concave portion 23c.

The base end side of the through hole 23b of the support member 23 is closed by a sealing member 27 having a hole 27a through which the tensile material 22 is inserted, and grease is filled in the through hole 23b. 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 by 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. The support member 23
The pressing load acting on the beam 21 in the tensioning direction via the taper peripheral surface 23a of the support member 23 and the tapered hole 2 of the beam 21
1d. Therefore, simplification of reinforcement can be obtained without a load in the tension direction acting intensively 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. However, 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 connected to the beam. It is also possible to fix to the end of the anchor hole that opens at the other end of the.

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

[0051]

According to the structure for imparting compressive stress of a structure according to the present invention described above, a support member having a tapered peripheral surface that tapers in the direction of tension is integrally embedded in the structure. The pressing load acting in the tensioning direction of the structure is dispersed through the support member accompanying the tension of the tension member, the load acting in the tensioning direction of the structure can be reduced, and the size reduction and reinforcement of the structure that receives the load can be achieved. Since the support member is formed integrally with the structure, the number of parts can be reduced, the manufacturing cost of the structure can be reduced, and the transportation and enforcement to the construction site can be effectively performed. Significant cost reduction can be expected.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a 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 member 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 view of a test outline for measuring a breaking load of a conventional anchor head in comparison with a breaking load of an anchor head in the present embodiment.

FIG. 6 is an explanatory perspective view of a support member of another mode used in the present embodiment.

FIG. 7 is a cross-sectional view of a principal part illustrating a connection between a beam and a column of a building, showing another embodiment of the compressive stress applying structure of the structure according to the present invention.

FIG. 8 is a sectional view of a main part showing still another embodiment of the compressive stress applying structure for a structure according to the present invention.

FIG. 9 is a sectional view of a main part for explaining a head structure of a conventional ground anchor.

FIG. 10 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 (2nd structure) 2c Through-hole 2d Tapered hole 3 Tensile material 3b Tip 4 Support member 4a Peripheral surface 5 Cone 11 Beam (1st structure) 12 Tensile material 12a Tip 13 Pillar (second structure) 13c Through hole 13d Tapered hole 14 Support member 14a Peripheral surface 21 Beam 21d Tapered hole 22 Tensile material 22a Tip 23 Support member 23b Through hole

────────────────────────────────────────────────── ─── 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-A-51-141440 (JP, A) JP-A-6-17424 (JP, A) JP-A 62-172735 (JP, U) JP-A 62-15310 (JP, Y2) (58) Field surveyed (Int.Cl. ⁷ , DB name) E02D 5/74-5/80 E02D 17/20

Claims (7)

(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 member through the through-holes formed in the second structure located on the surface of the first structure, apply tension to the tension member, and via the support member. In the structure for applying a compressive stress to the support member, the support member is tapered toward the base end direction of the tensile member, and this support member is
Tapering toward the base end of the tensile member provided on the second structure
Frustoconical or pyramidal frustum-shaped tapered hole inside
A structure for applying compressive stress to a structure, wherein the structure is provided so as to be buried integrally with the second structure. 2. The structure according to claim 1, wherein the support member is made of a material having higher strength than the second structure. 3. The tension member according to claim 1, wherein a tip of the tension member is connected to the cone, and is supported by the support member via the cone.
A compressive stress imparting structure for the structure described in the above. 4. The structure according to claim 3, wherein at least a part of the cone is accommodated in a recess formed in the support member. 5. The structure according to claim 1, wherein the first structure is ground and the second structure is a block placed on the ground surface. 6. A tensile member is inserted from one end of the structure into an anchor hole opened toward the inside of the structure to fix a base end of the tensile member serving as an anchor body. In a structure in which the distal end is supported by a support member located on the surface of the structure and applies tension to the tensile member to apply a compressive stress to the structure via the support member, the support member moves toward the tensile member proximal direction. a tapered shape that is tapered, this
The support member is directed toward the proximal end of the tensile member provided on the structure.
Of the tapered hole of the truncated cone or the truncated pyramid
A structure for applying compressive stress to a structure, wherein the structure is provided on an inner surface and is embedded in the structure integrally with the structure. 7. The structure according to claim 6, wherein the anchor hole is a 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. Compression stress applying structure.