JP2003213795A - Anchorage section of anchor body and its formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anchorage section of an anchor body and its formation method capable of increasing resistance force of an anchorage section against tensile force or the like acting on a member when the anchorage section is formed in the existing concrete for connecting a seismic element and others to be newly added to the existing structure. <P>SOLUTION: The surface layer side of the existing concrete 1 is partially eliminated, the anchor body 3 is inserted inside of the part 2 to be eliminated and, at the same time, at least a partial section in the direction of the depth in the whole part 2 to be eliminated is formed in the shape having a sectional area on the inner side larger than a sectional area on the surface side when the anchorage section 5 of the anchor body 3 is constituted by filling the inside of the part 2 with a filler 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to structural members such as seismic resistant elements, non-structural members such as wall panels, etc., to concrete, such as columns, beams, wall surfaces, foundations, etc. of existing structures, or members for facilities, etc. The present invention relates to a fixing portion of an anchor body that is formed for attaching the additional member and a forming method for forming the fixing portion.

[0002]

2. Description of the Related Art For example, a brace for seismic reinforcement on the surface side of a concrete skeleton of an existing structure such as an outer wall including columns and beams of an existing building or footing (foundation) of an existing bridge pier. When newly installing the seismic resistant element, the end of the seismic resistant element must be connected so that the tensile force and compressive force that the seismic resistant element bears can be transmitted to the existing concrete without damaging the existing concrete.

Generally, a core tube is used to remove a part of the existing concrete in a cylindrical shape from the surface side to the back side, and an anchor body such as an anchor bolt is inserted into the removed part, and mortar or concrete, Alternatively, the anchor body is fixed to the existing concrete by filling a filler such as an adhesive, and the end portion of the seismic resistant element is connected to the anchor body.

In this case, the compressive force from the seismic resistant element is transmitted from the bottom surface of the anchoring portion to the existing concrete as a bearing pressure, but the tensile force from the seismic resistant element is combined with the filler filled in the removed portion. , It is not sufficient because only the adhesive force between the removed portion and the inner peripheral surface can be expected.

In order to increase the resistance to the tensile force, it is necessary to increase the depth and diameter of the removed portion or increase the number of removed portions. In either method, the range of the removed portion is widened, and concrete is removed. Since the possibility of damaging the reinforcing bar by increasing the collision with the reinforcing bar inside, the reliability of the existing concrete after anchoring the anchor body is lowered, and it may be necessary to over-strike the concrete.

From the above background, the present invention proposes a fixing portion of an anchor body having a large resistance to a tensile force acting on a newly added seismic resistant element and other members, and a method of forming the same.

[0007]

According to the present invention, a part of a fixed material such as existing concrete on the surface layer side is removed, an anchor body is inserted into the removed part, and a filler is filled to anchor the anchor. In constructing the fixing part of the body, the cross-sectional area on the back side is larger than the cross-sectional area on the surface side in at least a part of the depth direction of the entire portion of the existing concrete and other fixed material removal parts. By forming the portion, the resistance to the pulling force acting on the anchor body is increased without expanding the range of the removed portion.

The above-mentioned cross-sectional area of the removed portion of the material to be fixed refers to the area of the cross section orthogonal to the axis of the anchor body, and the removed portion is in at least a part of the depth direction. In addition to a shape that has a portion that gradually expands in a stepwise manner toward the back side or continuously, the cross-sectional area of the entire removed portion gradually or gradually expands toward the back side,
In some cases, a section having a small cross section and a section having a large cross section are alternately repeated.

In terms of formation of the removed portion, the removed portion is divided into two sections in the depth direction on the surface side and the back side, and the section on the surface side has a cylindrical shape, and the section on the back side is formed. Is the simplest shape, and it is easy to form.

In any of the shapes, the removed portion of the material to be fixed such as concrete has a portion having a larger cross-sectional area on the inner side than the cross-sectional area on the surface side, so that the filler to be filled in the removed portion is existing. When a pulling force is applied to the surface of the material to be fixed such as concrete, the material to be fixed has a locking portion that can be locked or can be locked to the surface of the material to be fixed in the removed portion. In the case of the second aspect, the surface on the front surface side of the rear side section serves as the locking portion.

Due to the shape of the filler having this locking portion,
In addition to the adhesive force between the filler and the inner peripheral surface of the removed part, the bearing force between the anchor and the anchored material fixed in the filler is Since it resists by the resistance force, the resistance force increases as compared with the case of only the adhesive force.

By increasing the resistance of the filler, it is not necessary to expand the range of the removed portion by increasing the depth or diameter of the removed portion or increasing the number thereof, as compared with the case where it depends only on the adhesive force. Therefore, for example, the risk of damaging the reinforcing bars by collision with the reinforcing bars in concrete, that is, the influence on the proof stress of the existing concrete or the like is eliminated, and the reliability of the existing concrete or the like after fixing the anchor body is improved. For this reason, there is no need for special overfilling of concrete or the like to secure the proof stress of existing concrete or the like.

In particular, as described in claim 3, at least a part of the entire removed portion in the depth direction has a shape in which the cross-sectional area gradually increases from the surface side to the back side as described above. In this case, the anchoring portion is inclined with respect to the cross section orthogonal to the axis of the anchor body, so that the anchorage material of the existing concrete or the like can resist the pulling force received from the filler to the outer edge of the anchoring portion of the filler. Since it resists in a region that gradually expands from the surface of the material to be fixed to the surface of the material to be fixed, the safety of the material to be fixed such as existing concrete is high.

The effect that the material to be fixed resists the pull-out force in the region where it gradually expands from the outer edge of the locking portion of the filling material to the surface side of the material to be fixed is as described in claim 5. It is further improved by forming the tip portion in a shape in which the cross-sectional area increases from the head portion side to the tip portion side.

In this case, the section having a shape in which the cross-sectional area gradually expands from the surface side to the back side of the removed portion is formed at least at the tip of the anchor body. The withdrawal force acting on the tip of the anchor body is applied to the filler due to the cone-like shape of the tip of the anchor body, and to the area that gradually expands from the tip of the anchor body to the head side as shown by the broken line in FIG. 10. Since it is transmitted to the fixed material over a wider area than the outer edge of the locking portion of the filling material, the fixing material resists the pulling force more than when the locking portion is formed on the filling material. And the effect of resistance of the material to be fixed is improved.

As a concrete shape example of claim 3, as described in claim 4, the removed portion is divided into three sections of a front surface side section, a rear side section and an intermediate section thereof, and the front surface side The section has a cylindrical shape, the middle section has a truncated cone shape, and the rear side section has a cylindrical shape with a diameter larger than that of the front side section.
In this case, the locking portion is formed on the surface on the surface side of the middle section of the truncated cone shape, and has a shape in which the diameter gradually increases from the surface side to the back side.

The removed portion of the material to be fixed is formed, for example, by removing the central portion on the cross section of the removed portion by rotating a core tube having a cutting blade at the tip as described in claim 8 and then removing the central portion. The peripheral portion is formed by rotating and removing a bit having a cutting blade on the tip or the peripheral surface.

In this case, the core tube is continuously removed in a cylindrical shape from the section on the surface side to the section on the back side of the material to be fixed such as existing concrete, so that the bit is inserted to the section on the back side and Since the peripheral portion can be removed in the side section, the material to be fixed can be removed more easily and efficiently than when the bit is used from the beginning, and the peripheral section of the inner section can be removed at any depth. Therefore, it is possible to form it into a free shape.

When the base plate is arranged on the surface of the material to be fixed and the anchor body is axially tensioned in the fixing state, the reaction force of the tension force is the back surface of the base plate. Is transmitted as a compressive force from the anchor to the material to be fixed and is borne in the area of the material to be gradually expanded from the surface side to the inner side, and as a result, the compressive force is applied to the fixing portion of the anchor body and the fixing material. Since it acts as a resistance against pulling out or coming out of the surrounding fixed material, the stability of the fixing portion of the anchor body to the fixed material is significantly improved.

In this case, the tension force acting on the tip of the anchor body is transmitted to the filling material in the removed portion, and the fixing material at the back side is from the outer edge of the locking portion of the filling material to the surface side of the fixing material. It resists in the region that gradually expands toward the front side, and on the surface side, as shown by the broken line in FIG. 11, the presence of the base plate bears the compressive force in the region that gradually expands from the front side to the back side. The anchor body will not come out of the material to be fixed unless the material to be fixed is destroyed.

According to a sixth aspect of the present invention, since the fixing portion of the anchor body to the fixing material is stable against slipping out, the plate is joined to the head portion of the anchor body protruding from the surface of the base plate as described in the seventh aspect. However, when structural members, non-structural members, etc. are joined to the plate, the axial force that repeatedly acts on the anchor body from the structural members, non-structural members, etc. is mainly due to the portion of the anchor body protruding from the base plate. The expansion and contraction can bear the load, and the influence of the anchor body on the fixing portion of the fixing material is reduced, so that the stability of the fixing portion of the anchor body can be obtained against repeated load.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 removes a part of the surface layer side of the existing concrete 1 and other materials to be fixed,
The anchor portion 3 of the anchor body 3 is formed by inserting the anchor body 3 into the removed portion 2 and filling the filling material 4.

The fixing section 5 is mainly used for pillars and beams of existing buildings,
In addition to concrete parts such as wall surfaces and foundations, concrete parts such as bridge girders and piers and foundations (footings) of existing bridges are also structural members such as seismic resistant elements and non-structural members such as wall panels.
Or when adding other members for equipment,
It is partially formed on the material to be fixed such as the existing concrete 1.

The material to be fixed includes both structural members and non-structural members depending on the role of anchoring the anchor body 3 to the material to be fixed, and can be perforated like stone, brick, concrete block, etc. in addition to concrete. Includes all possible materials. In the following, the existing concrete 1 is representative of the material to be fixed.

Since the anchor portion 5 can be formed by having the part of the existing concrete 1, it does not matter whether the existing structure is a building structure or a civil engineering structure, and the structure of the structure body. It does not matter whether is a reinforced concrete structure (steel frame reinforced concrete structure) or a steel frame structure.

1 to 4 show a case where a brace 7 as an earthquake resistant element is installed around an existing bridge pier or other column base 6,
A case where a fixing portion 5 for fixing a gusset plate 9 that connects the ends of the braces 7 is formed on the foundation 8 as the existing concrete 1 is shown.

In the drawing, the removed portion 2 has a shape in which the cross-sectional area gradually increases from the front surface side to the back side as a whole.
In the case of, especially, the removed portion 2 is divided into the front side section and the back side section,
And the case of claim 4 divided into sections in between.

In the case of claim 4, the middle section is formed in a frusto-conical shape in which the cross-sectional area gradually expands from the surface side to the back side, but the removed portion 2 has at least a part in the depth direction. Since it is sufficient for the section to have a portion where the cross-sectional area on the back side is larger than the cross-sectional area on the front side, the shape without the middle section of claim 4, that is, the section on the front side is cylindrical, and the section on the back side is May be formed in a cylindrical shape having a diameter larger than the section on the front surface side (claim 2).

In addition to the above, the removed portion 2 may have a shape in which a truncated cone and a cylinder are combined without a surface-side section in claim 4 or a shape having only a truncated cone in an intermediate section.

Further, the removed portion 2 may have a portion having a larger cross-sectional area on the back side than the cross-sectional area on the front side in a part of the section.
Alternatively, since it is not necessary to gradually increase the shape, the removed portion 2 having the shape shown in the figure or the shape having no part of the above-described shape is alternately repeated in the depth direction. 2 may be formed in some cases.

As shown in FIG. 1 and FIG. 3 which is an enlarged view of a part of the existing concrete 1, the removed portion 2 has a portion having a larger cross-sectional area on the back side than the cross-sectional area on the front surface side. The filling material 4 such as mortar, concrete, or an adhesive to be filled receives the pulling-out force of the existing concrete 1 acting on the anchor body 3 toward the surface side of the existing concrete 1 and removes the existing concrete 1 to the surface side thereof. It has a shape having a locking portion 4a that can be stopped or engaged.

When the removed portion 2 is divided into two or more sections in the depth direction as shown in the figure, the locking portion 4a is formed in the removed portion 2 at a portion closer to the front surface side than the inner portion. . In the case of only the truncated cone shape or including the truncated cone shape, the locking portion 4a is formed in a portion closer to the surface side in a shape inclined with respect to a cross section orthogonal to the axis of the anchor body 3.

The removed portion 2 is, for example, as shown in FIG. 7, the central portion on the cross section thereof is removed by removing the cylindrical portion by rotating the core tube 10 having the cutting blade 10a at the tip, and then, as shown in FIG. The peripheral portion of the portion is formed by rotating a bit 11 having a cutting edge 11a at the tip or the peripheral surface thereof, such as a cylinder or a blade, to remove it into a truncated cone shape or a column shape.

Although not shown, a bit in which the cutting blade is eccentric to the shaft of the drive shaft 12a or the rod to which a rotational force is applied from the drive device 12 or the shaft is bent to the shaft of the drive shaft 12a or the rod. By using a bit of a shape, after removing it in a cylindrical shape by the core tube 10, or from the beginning without using the core tube 10, a removed portion in a cylindrical shape, a truncated cone shape, or a combination of a circular column and a truncated cone. 2 can also be formed. In addition, the removed portion 2 can be formed in an arbitrary shape by jetting water at an ultrahigh pressure.

In the case of FIGS. 7 and 8, the core tube 10 is connected to the drive shaft 12a of the drive device 12 supported by the support member 13 temporarily fixed to the surface of the existing concrete 1 so as to be able to move up and down. The core tube 10 is rotated around the axis of the drive shaft 12a, so that the cutting blade 10a at the tip separates concrete shown by hatching into a columnar shape from the periphery. Cylindrical concrete is pulled out in the same shape as core removal. As shown in FIGS. 5 and 6, when the removed portion 2 is formed on the side surface of the existing concrete 1, the support member 13 is fixed sideways.

Then, as shown in FIGS. 8 and 9, instead of the core tube 10, for example, a rod 11b to which a cylindrical bit 11 is connected is attached to an attachment 14 which is eccentrically connected to the drive shaft 12a. Drive shaft 12 connected to the tip of 12a
a is rotated to rotate the bit 11 around the drive shaft 12a, and the rotation of the drive shaft 12a is transmitted to the rod 11b of the bit 11 to rotate the bit 11 so that the hatching around the cylindrical removal portion is performed. The concrete shown by is crushed into a truncated cone shape or a column shape. The crushed concrete powder is expelled by injecting air or by aspirating, forming the removed part 2.

After the removed portion 2 is formed, the filler 4 is formed inside the removed portion 2.
The fixing portion 5 is formed by filling the above and inserting an anchor body 3 suitable for the type of member added to the existing concrete 1, such as anchor bolts, reinforcing bars, and steel pipes. A fixing member such as a protrusion, a stud bolt, a fixing plate, or the like for obtaining an adhesive force or a supporting pressure between the anchor body 3 and the filling member 4.
3b is projected.

In the case of FIGS. 1 to 4, in order to fix the head of the anchor body 3 to the top end of the foundation 8, a rectangular base plate 15 surrounding the column base 6 is arranged on the foundation 8. The head of the anchor body 3 penetrates the base plate 15 and is fixed to the foundation 8 by tightly connecting the nut 3a from the base plate 15.

A band plate 16 for dispersing and transmitting the tensile force and the compressive force from the brace 7 to the column base 6 is arranged around the column base 6, and is integrated with the base plate 15.
In the space between the inner periphery of the band plate 16 and the periphery of the column base 6, a filling material 17 such as mortar for protecting the surface of the column base 6 is provided.
Is filled.

The gusset plate 9 is joined across the base plate 15 and the band plate 16, and the bracket 7a connected to the end of the brace 7 is rotatably connected to the gusset plate 9 by pins 7b or the like. In FIG. 2, the fixing portion 5 including the anchor body 3 and the filling material 4 is also provided below the portion of the base plate 15 where the gusset plates 9 and 9 are joined.
Are formed.

In FIG. 3, the diameter of the section on the surface side of the removed portion 2 is 10
An example of how the anchor body 3 fits in is about 0 mm and the diameter of the inner section is about 200 mm is shown. Fig. 4 corresponds to the case of securing a pullout resistance larger than that of Fig. 3, and the removal part 2 Enlarged the whole diameter, and attached to the fixed attachment part 5, many (3
The fixing unit 5 when the anchor bodies 3 of (more than one) are arranged as a group is shown. In FIG. 4, 9a indicates an insertion hole through which the pin 7b is inserted.

For example, when the fixing portion (filler) has a cylindrical shape and a large number of anchor bolts are arranged as a group, the pulling force acting on the entire anchor bolt group is borne by each anchor bolt. Even if it is smaller than the total pull-out resistance force, the anchor bolt group is integrated and the pull-out force that acts on the entire anchor bolt group acts on the entire filling material, so all anchor bolts are pulled out together with the filling material. Is assumed.

On the other hand, in the case of the present invention shown in FIG. 4, the pull-out force acting on the entire group of anchor bodies 3 is the filling material 4.
Even if it acts on the whole of the anchor, since the filler 4 resists by the bearing pressure in the locking portion 4a, the group of anchor bodies 3 is
The situation of being pulled out with is avoided.

FIG. 5 shows that when the existing concrete 1 is the beam 18 of the building, the anchoring portion 5 is formed on the side surface of the beam 18 and the anchoring portion 5 is formed.
The case where the brace 7 is connected to the anchor body 3 is shown. In FIG. 5, since anchor bolts and PC steel rods are used for the anchor body 3, the head of the anchor body 3 is attached to the base plate 15.
After being fixed to the side surface of the beam 18 with the nut 3a, the bracket 7a of the brace 7 is directly connected with the nut 3a without using the gusset plate 9 on the head of the anchor body 3.

When the brace 7 is connected to the beam 18 of the existing concrete 1, the shear force is transmitted to the beam 18 by the tensile force and the compressive force from the brace 7, but the shearing force causes the anchor body 3 to shear. Since it is advantageous to have a shape having a large projected area in the acting direction of force, in order to reliably transmit the shearing force from the anchor body 3 to the beam 18, as shown in FIG. It is effective to use a steel pipe 32 having a larger diameter.

In FIG. 6, the anchor body 3 is composed of an anchor bolt 31 to which the bracket 7a is joined, a steel pipe 32 surrounding the outer circumference of the anchor bolt 31, and an arm 33 connecting the two, and the force from the anchor body 3 already exists. In order to be directly transmitted to the concrete 1, the steel pipe 32 is inscribed in a section on the surface side of the removed portion 2, and a fixing material 3b such as a stud bolt is projected in a section on the back side of the steel pipe 32.

The filler 4 is attached to the lower side of the anchor body 3 in the state where the end face of the steel pipe 32 exposed on the side surface of the beam 18 is closed.
An injection hole communicating from the side surface of 18 to the removed portion 2
The filling is continued from the side of the beam 18 to the removed portion 2 on the upper side of the anchor body 3 until it overflows from the discharge hole 1b which is formed by communicating with the side surface of the beam 18, and the inside of the removed portion 2 and the steel pipe. The inside of 32 is packed densely.

Although the anchor bolt 31 and the steel pipe 32 are integrated by the arm 33, the filler 4 filled inside the steel pipe 32 is used.
Since the force is mainly transmitted between the anchor bolt 31 and the steel pipe 32, it suffices to connect the anchor bolt 31 and the steel pipe 32 to the extent that the arm 33 does not hinder the filling of the filling material 4 into the steel pipe 32.

In the case of FIGS. 5 and 6, a bending moment acts on the anchor bolt 31 by the tensile force and compression force from the brace 7, but in the case of FIG.
Since the steel pipe 32 is integrated with the steel pipe 31, the cross-sectional performance of the anchor body 3 is improved, so that the resistance force against the bending moment of the anchor body 3 is increased as compared with the case of only the anchor bolt shown in FIG.

Therefore, even if the periphery of the head of the anchor bolt 31 protruding from the beam 18 is not constrained by concrete or the like, the anchor body 3 exerts a sufficient resistance force against the bending moment as compared with the case of FIG. It

Further, the inner side of the steel pipe 32 constituting the anchor body 3 is fixed to the inner side of the removed portion 2 having a large cross-sectional area by the fixing material 3b.
By being fixed by the above, the entire fixing portion 5 in which the anchor body 3 and the filler 4 are integrated resists the bending moment. Moreover, since the cross-sectional area on the inner side of the fixing portion 5 where the bending moment is maximized is enlarged, the tip portion as the anchor body 3 is larger than the conventional case where the removed portion 2 and the filler 4 are formed in a columnar shape. The proof stress against the bending moment is increased.

At the same time, the shear force from the brace 7 is transmitted to the beam 18 through the steel pipe 32 inscribed in the section on the surface side of the removed portion 2 and the filler 4 in the section on the back side having a large cross-sectional area.
Burdened by 18.

As described above, the anchor body 3 and the fixing portion 5 including the anchor body 3 have high resistance to not only the axial tensile force as in FIGS. 1 to 4 but also the bending moment and the shearing force. Will have.

FIG. 10 shows an example of forming the fixing portion 5 according to claim 5 in which the tip portion 3c of the anchor body 3 is formed in a shape in which the cross-sectional area increases from the head side to the tip side. Here, the tip portion 3c is formed in a truncated cone shape, but the shape of the tip portion 3c does not matter and does not necessarily have to be a solid cross section. Figure
As in FIG. 1, reference numeral 10 shows a fixing state of the fixing portion 5 when the existing concrete 1 is the foundation 8 and the fixing state of the base plate 15 with the gusset plate 9 to the anchor body 3.

The reaction force with respect to the pulling force received by the anchor body 3 is transferred from the tip portion 3c of the anchor body 3 to the filling material 4 by the tip portion.
Since it is transmitted to the area that expands from 3c to the head side and is transmitted from the filler 4 to the existing concrete 1, the filler 4
Depending on the position where the locking portion 4a is formed, it is transmitted over a wider area than the outer edge thereof.

The reaction force against the pulling force is transmitted to the filling material 4 and the existing concrete 1 in a range surrounded by a line perpendicular to the outer peripheral surface of the tip portion 3c of the anchor body 3 as shown by a broken line in FIG. However, when the outer edge of the locking portion 4a is inside the range as shown in FIG. 10, the reaction force is transmitted to a wider range than the outer edge of the locking portion 4a.

In FIG. 11, the head of the anchor body 3 is largely projected from the base plate 15 arranged on the surface of the existing concrete 1, and the anchor body 3 is axially tensioned in the fixed state and its reaction force is applied. The fixing unit 5 according to claim 6, wherein the existing concrete 1 is loaded through the base plate 15.
An example of the formation of The tension force fills the filler 4 into the removed portion 2 and inserts the anchor body 3 into the removed portion 2,
It is provided after the filler 4 is cured.

In this case, the reaction force of the tension force is the base plate.
Since the compressive force is transmitted from the back surface of the existing concrete 1 to the existing concrete 1 and is applied in the area of the existing concrete 1 that gradually expands from the front surface side to the inner side as shown by the broken line, the reaction force is transmitted from the base plate 15 to the existing concrete 1. 11, the filler 4 filled in the removed portion 2 in order to secure the close contact between the back surface of the base plate 15 and the surface of the existing concrete 1 wraps around the back surface of the base plate 15 in FIG. The gap between the surface of the existing concrete 1 is filled.

In the case of FIG. 11, the plate 19 is joined to the head of the anchor body 3 protruding from the surface of the base plate 15,
A gusset plate 9 for connecting various members such as structural members and non-structural members is joined to the plate 19.

In FIG. 11, when a structural member or a non-structural member is joined to the gusset plate 9 of the plate 19 or the like,
The anchoring portion of the anchor body 3 into the filling material 4 and the protruding portion so that the axial force repeatedly acting on the anchor body 3 from the structural member or the non-structural member is applied to the portion of the anchor body 3 protruding from the base plate 15. In order to distinguish the above, the base plate 15 is fixed by the nut 3a, and then the plate 19 is joined to the protruding portion of the anchor body 3 by the nuts 20 and 20 from both surface sides.

In both cases of FIG. 10 and FIG. 11, in order to improve the integrity by the adhesion (adhesion) of the anchor body 3 to the filler 4 at the fixing portion of the anchor body 3, the anchor body 3 is covered over its entire length. Alternatively, it is preferable to increase the attachment area by cutting a screw or forming a node as shown in the entire length excluding the tip portion 3c.

[0062]

EFFECTS OF THE INVENTION A part of the surface layer side of the existing concrete is removed into a shape having a portion having a larger cross-sectional area on the inner side than the cross-sectional area on the surface side, and by inserting an anchor body and filling with a filler in the removed portion. By constructing the fixing part, the filling material forms a locking part that can be locked or can be engaged with the existing concrete on the surface side in the removed part, so that the filling material against the pulling force acting on the anchor body is formed. In addition to the adhesive force of the above, it is possible to resist by the bearing pressure between the locking portion and the existing concrete, and the resistance force can be increased as compared with the case of only the adhesive force.

As a result, since it is not necessary to expand the range of the removed portion such as the number of fixing portions can be reduced as compared with the case of only the adhesive force, there is no influence on the proof stress of the existing concrete due to the damage of the reinforcing bar in the concrete, Improves the reliability of existing concrete after anchoring, and does not require overcasting of concrete.

In the second aspect, the removed portion is divided into two sections in the depth direction, the front side and the back side, the front side section is cylindrical, and the back side section is cylindrical with a diameter larger than the front side section. Since it is formed in the same manner, it is easy to form the removed portion.

In claims 3 and 4, of the entire removed portion,
By forming at least a part of the section in the depth direction from the surface side to the back side to form a shape in which the cross-sectional area gradually expands, a locking portion inclined with respect to the cross section orthogonal to the axis of the anchor body is formed. Therefore, the existing concrete will resist the pulling force received from the filling material in the region that gradually expands from the outer edge of the locking portion of the filling material to the surface side of the existing concrete, and the safety against the destruction of the existing concrete is Increase.

According to the fifth aspect of the present invention, the distal end portion of the anchor body is shaped so that the cross-sectional area increases from the head side to the distal end side, so that the pull-out force acting on the distal end portion of the anchor body is Due to the cone shape, it is transmitted to the filler in a region that gradually expands from the tip of the anchor body to the head side, and can be transmitted to the fixed material over a wider range than the outer edge of the locking portion of the filler. Therefore, a region in which the material to be fixed resists the pull-out force is expanded as compared with the case where only the locking portion is formed in the filling material, and the effect of resistance of the material to be fixed is improved.

In the sixth aspect, the base plate is arranged on the surface of the material to be fixed, and a tension force is applied to the anchor body in the fixing state in the axial direction, whereby the reaction force of the tension force is applied from the back surface of the base plate to the material to be fixed. Since it is transmitted as a compressive force and is applied in a region of the fixed material that gradually expands from the surface side to the back side, the compressive force is applied to the fixing portion of the anchor body to the fixing material and the fixing material surrounding it. On the other hand, it can act as a resistance force against pulling out or coming out, and the stability of the fixing portion of the anchor body to the fixing material is significantly improved.

According to a seventh aspect of the present invention, the plate is joined to the head portion of the anchor body protruding from the surface of the base plate so that the structural member or the non-structural member joined to the plate repeatedly acts on the anchor body. Since the axial force generated by the anchor body can be mainly applied to the part of the anchor body projecting from the base plate, the influence of the anchor body on the fixing part to the material to be fixed is reduced, and the anchor body is resistant to repeated load. The stability of the fixing part of is secured.

In the eighth aspect, after removing the central portion on the cross section of the removed portion by rotating the core tube having the cutting blade at the tip, the peripheral portion of the central portion is provided with the cutting blade at the tip or the peripheral surface. To rotate and remove the bit you have,
The existing concrete can be removed more easily than when a bit is used from the beginning, and the peripheral portion can be freely formed from any depth.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which a fixing portion is formed on a foundation as existing concrete.

2 is a cross-sectional view of FIG.

FIG. 3 is an enlarged view of a fixing unit in FIG.

FIG. 4A is a vertical cross-sectional view showing a fixing portion when anchor bodies are arranged as a group, and FIG. 4B is a cross-sectional view of FIG. 4A.

FIG. 5 is a vertical cross-sectional view showing a state in which a fixing portion is formed on a beam as existing concrete.

FIG. 6 (a) is a vertical cross-sectional view showing another example in which an anchor portion is formed on a beam as existing concrete, and (b) is xx of (a).
FIG.

FIG. 7 is an elevational view showing how a central portion of a removed portion is removed.

FIG. 8 is an elevational view showing how the peripheral portion of the removed portion is removed.

9 is a perspective view showing the relationship between the bit and the drive shaft shown in FIG.

FIG. 10 is a vertical cross-sectional view showing an example of formation of a fixing portion according to claim 5;

FIG. 11 is a vertical cross-sectional view showing an example of forming the fixing unit according to claims 6 and 7.

[Explanation of symbols]

1 ... Existing concrete, 1a ... Injection hole, 1b ... Discharge hole, 2 ... Removed part, 3 ... Anchor body, 3a ... Nut, 3b ... Fixing material, 3c ... Tip part, 4 ... Filler, 4a ...
... Locking part, 5 ... Fixing part, 6 ... Column base, 7 ... Brace, 7a ... Bracket, 7b ... Pin, 8 ... Foundation, 9 ...
… Gusset plate, 9a… Insertion hole, 10… Core tube, 10a… Cutting blade, 11… Bit, 11a… Cutting blade,
11b ... Rod, 12 ... Drive device, 12a ... Drive shaft, 13
…… Supporting member, 14 …… Attachment, 15 …… Base plate, 16 …… Band plate, 17 …… Filling material, 18 ……
Beam, 19 ... plate, 20 ... nut.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidekuni Hyokawa             1-13-1 Yamashita, Okayama City, Okayama Stock             Company Omotogumi F-term (reference) 2E125 AA76 AG11 BA14 BA22 BB08                       BB29 BB30 BD01 BE05 BF04                       CA04 CA82                 2E164 DA26 DA27 DA29

Claims (8)

[Claims] 1. A fixing portion of an anchor body, which is formed by removing a part of a surface of a material to be fixed to which the anchor body is fixed, inserting the anchor body into the removed portion, and filling a filler. The anchoring portion of the anchor body, which has a portion having a larger cross-sectional area on the inner side than the cross-sectional area on the front surface side in at least a part of the depth direction of the entire removed portion. 2. The removed portion is divided into a front-side section and a back-side section, the front-side section has a cylindrical shape, and the back-side section has a cylindrical shape with a diameter larger than that of the front-side section. Claim 1
The anchoring part of the described anchor body. 3. The anchor body according to claim 1, wherein at least a part of the entire removed portion in the depth direction has a shape in which the cross-sectional area gradually increases from the surface side to the back side. Fixing unit. 4. The removed portion is divided into a surface-side section, a back-side section, and an intermediate section thereof. The surface-side section has a cylindrical shape, and the intermediate section has a truncated cone shape, The fixing portion of the anchor body according to claim 3, wherein the section has a cylindrical shape having a diameter larger than that of the surface side section. 5. The anchor portion of the anchor body according to claim 1, wherein the tip portion of the anchor body has a shape in which a cross-sectional area increases from the head side to the tip side. 6. The base plate is arranged on the surface of the material to be fixed, the tension force is applied to the anchor body in the axial direction in the fixed state, and the reaction force is borne by the material to be fixed via the base plate. The anchor portion of the anchor body according to any one of claims 1 to 5. 7. The anchor portion of the anchor body according to claim 6, wherein the plate is joined to the head portion of the anchor body protruding from the surface of the base plate. 8. A core tube having a cutting blade at the tip is rotated to remove the central portion of the cross section of the removed portion of the fixing material to which the anchor body is fixed, and then the peripheral portion of the central portion is removed. Alternatively, a method of forming a fixing portion of an anchor body, wherein a bit having a cutting blade on a peripheral surface thereof is rotated and removed to form a removed portion according to any one of claims 1 to 7.