Core rod driving type anchor and construction method of the same

Abstract

To provide a core rod driving type anchor which ensures smooth insertion into a bore hole in which an adhesive is injected and enables the adhesive in the bore hole to adhere thereto sufficiently to achieve high anchor strength.SOLUTION: A core rod driving type anchor 10 includes: a sleeve-like anchor body 11; and a core rod 12 inserted into the anchor body 11. The anchor body 11 is provided with an expansion piece 14 which is divided by slits 13 cut from a tip in an axial direction. The core rod 12 is driven to cause a tip 121 of the core rod 12 to enter a step part 15 located at the inner side of the expansion piece 14 and thereby expand the expansion piece 14. Further, a spiral groove 18 serving as a passage of an adhesive 30 is formed in an entire outer periphery located at the front relative to a rear end 16 of the anchor body 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a core rod driving anchor used, for example, when attaching an object to a concrete structure that has deteriorated over time or a concrete structure that has become weakened, and to a method for installing the same. [Background technology]

[0002] Conventionally, there is a core rod driving type anchor disclosed in Patent Document 1 as a core rod driving type anchor used when attaching an attachment to a concrete structure that has deteriorated over time. The core rod driving type anchor of Patent Document 1 is composed of a sleeve-shaped anchor body and a core rod inserted into the anchor body. The anchor body has a plurality of slits cut in the axial direction from the tip, and an extension piece divided by slits spaced apart in the circumferential direction is provided at the tip. An intermediate section whose outer periphery is a cylindrical surface is provided at the rear of the tip of the anchor body, and a male threaded section with a male thread formed on the outer periphery is provided at the rear of the intermediate section.

[0003] A step is formed on the inside of the expansion piece of the anchor body, and the expansion piece expands when the core rod is driven in and the warhead-shaped tip enters the step.The core rod-driven anchor, which has its expansion piece expanded and driven into a concrete structure, supports the spalling prevention material that is laid along the mounting surface of the concrete structure together with the inserted plate and the nut screwed onto the male thread (see paragraphs

[0019] ,

[0024] , and

[0025] of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-111954 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when driving a core rod driving-in anchor into a concrete structure that has deteriorated over time or a weakened concrete structure, it is desirable to use an adhesive in combination to increase the anchor strength, insert the core rod driving-in anchor into a drilled hole into which adhesive has been injected beforehand, and drive in the core rod to expand the expansion piece.

[0006] However, when the core rod driving anchor of Patent Document 1 is cast in combination with an adhesive, there are cases where the adhesive does not flow smoothly between the cylindrical surface of the middle part and the hole wall, making it impossible to smoothly insert the core rod driving anchor into the borehole. Conversely, if the gap between the cylindrical surface of the middle part and the hole wall is too large, the adhesive does not adhere sufficiently to the core rod driving anchor, resulting in another problem of reduced anchor strength.

[0007] The present invention has been proposed in consideration of the above problems, and has an object to provide a core rod-driving anchor and an installation method thereof that can reliably perform smooth insertion into a borehole into which adhesive has been injected, and that can sufficiently adhere the adhesive inside the borehole to reliably exhibit high anchor strength. [Means for solving the problem]

[0008] The core rod driving anchor of the present invention is composed of a sleeve-shaped anchor body and a core rod inserted into the anchor body, the anchor body is provided with an expansion piece divided by a plurality of slits cut axially from its tip, the expansion piece is expanded when the core rod is driven in and the tip of the core rod enters a step portion on the inside of the expansion piece, and a spiral groove that serves as a flow path for the adhesive is formed around the entire outer periphery forward of the rear end of the anchor body. According to this, when the adhesive is injected into the drilled hole in advance and the core rod driving type anchor is driven, the adhesive flows along the spiral groove on the outer periphery of the anchor body, and the presence of the adhesive prevents the anchor from being hindered from being inserted into the drilled hole, and the core rod driving type anchor can be inserted reliably into the drilled hole into which the adhesive has been injected. In addition, the adhesive can be evenly distributed along the spiral groove over the entire outer periphery forward of the rear end of the anchor body. Then, the evenly distributed adhesive is made to adhere to the unevenness of the spiral groove, so that the adhesive in the drilled hole can be sufficiently attached over the entire outer periphery forward of the rear end of the anchor body, and high anchor strength can be reliably achieved. Therefore, for example, the anchor can be fixed with high strength in a deep part that is embedded deeper than the surface layer of a concrete structure that is likely to collapse due to weakness. In addition, by expanding the expansion piece and biting into the wall of the drilled hole, a fixing force with a certain degree of anchor strength can be obtained even before the adhesive hardens. In addition, since the core rod driving type anchor can be cast with high anchor strength, it is possible to improve the attachment strength of the object to be attached to the concrete structure using the core rod driving type anchor and to improve the stability of the installed state.

[0009] The core rod driving-in anchor of the present invention is characterized in that the spiral groove is formed by rolling processing. According to this, by forming the spiral groove on the outer periphery of the anchor body by rolling processing, it is possible to eliminate waste of material and reduce manufacturing costs. In addition, the spiral groove can be formed in a short time, thereby improving production efficiency.

[0010] The method of installing a core rod-driven anchor of the present invention is a method of installing a core rod-driven anchor of the present invention, and is characterized by comprising a first step of injecting adhesive into a borehole formed in a concrete structure, a second step of inserting the core rod-driven anchor into the borehole so that the rear end of the anchor body is exposed from the borehole and causing the unhardened adhesive to flow along the spiral groove, and a third step of driving in the core rod to expand the expansion piece and cause the expansion piece to bite into the wall of the borehole. According to this, the adhesive flows along the spiral groove on the outer periphery of the anchor body, and the core rod driving type anchor can be smoothly inserted into the drilled hole into which the adhesive has been injected. In addition, the adhesive can be evenly distributed along the spiral groove, and the adhesive can be attached to the unevenness of the spiral groove, so that the adhesive in the drilled hole can be sufficiently attached over the entire outer periphery forward of the rear end of the anchor body. In addition, by expanding the expansion piece and making it bite into the wall of the drilled hole, a fixing force with a certain degree of anchor strength can be obtained even before the adhesive hardens. In addition, since the core rod driving type anchor can be cast with high anchor strength, it is possible to improve the attachment strength of the attachment to the concrete structure to which the core rod driving type anchor is attached and improve the stability of the installation state. Effect of the Invention

[0011] According to the present invention, it is possible to reliably perform smooth insertion of a core rod-driven anchor into a borehole into which adhesive has been injected, and it is also possible to ensure that the adhesive in the borehole adheres sufficiently to the core rod-driven anchor, thereby reliably exhibiting high anchor strength. [Brief description of the drawings]

[0012] [Figure 1] 1A is a front view of a core rod driving-in anchor according to a first embodiment of the present invention, FIG. 1B is an enlarged left side view thereof, FIG. 1C is an enlarged right side view thereof, and FIG. [Diagram 2] FIG. 2 is a front view of the core rod driving-type anchor of the first embodiment in an expanded state. [Diagram 3] FIG. 2 is a perspective view of the inner surface of a tunnel lining to which a spalling prevention material is attached using the core rod driving anchor of the first embodiment. [Figure 4] FIG. 2 is a perspective view of a state in which a peeling prevention material is attached using a core rod driving anchor and a clip-type retainer of the first embodiment. [Diagram 5] FIG. 2 is a partial cross-sectional view of the first embodiment of the core rod-driven anchor and the clip-type retainer in a state in which the anti-peeling material is attached. [Figure 6] (a) is a front view of the clip-type retainer, (b) is a cross-sectional view thereof, and (c) is a rear view thereof. [Figure 7] FIG. 2 is a partial cross-sectional view of the core rod driving anchor of the first embodiment inserted into a drilled hole into which adhesive has been injected. [Figure 8] FIG. 2 is a partial cross-sectional view of the first embodiment of the core rod driving anchor in a state in which the core rod has been driven in and the expansion piece has been expanded within the borehole. [Figure 9] 6A is a front view of a core rod driving type anchor according to a second embodiment of the present invention, and FIG. 6B is a front view of the core rod driving type anchor according to the second embodiment in an expanded state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [First embodiment of core rod driving anchor] 1 and 2, a core rod driving type anchor 10 according to a first embodiment of the present invention is composed of a sleeve-shaped anchor body 11 and a core rod 12 inserted into the anchor body 11. The anchor body 11 in this example is formed in a substantially cylindrical shape, with multiple slits 13 cut in the axial direction from the tip, and an expansion piece 14 is provided so as to be divided by the multiple slits 13 spaced apart in the circumferential direction. A step portion 15 is formed on the inside of the expansion piece 14, and when the core rod 12 is driven in the tip direction, the warhead-shaped tip portion 121 enters the step portion 15, causing the expansion piece 14 to expand.

[0014] A male thread 17 is formed on the outer peripheral surface of the rear end 16 of the anchor body 11, and a nut 21 such as a locking nut is screwed onto the male thread 17 when the core rod driving anchor 10 is driven into a concrete structure 100 (see FIG. 5). A spiral groove 18 is formed on the entire outer periphery of the anchor body 11 in front of the rear end 16, which serves as a flow path for the adhesive 30. The spiral groove 18 is preferably formed on the outer periphery of the anchor body 11 by rolling, but it can also be formed by other processing methods such as cutting. The outer diameter of the spiral part of the anchor body 11 where the spiral groove 18 is formed is, for example, 8.2 mm, and the length of the spiral part corresponding to the embedding length is, for example, 15 times or more the outer diameter of the spiral part. In addition, a sawtooth part 122 is formed by serration processing near the rear end of the core rod 12, and the driven core rod 12 is prevented from slipping out of the anchor body 11 by frictional contact with the sawtooth part 122.

[0015] As shown in Figures 3 to 5, the core rod driving anchor 10 is cast into deteriorated concrete of a concrete structure 100, such as the deteriorated lining concrete of a tunnel T, and is used to support, together with a clip-type retainer 40, a planar anti-fall material 50 that is laid along the mounting surface 101 of the concrete structure 100.

[0016] The clip-type presser 40 is made of a metal material such as stainless steel, and includes a front plate 41 having steps around both ends in the width direction, and a flat back plate 42, with the back plate 42 folded back at a folded-back portion 43 that is curved in an arc shape in cross section and elastically deformable. The front plate 41 has a protruding step portion 44 formed adjacent to the folded-back portion 43, and another protruding step portion 45 formed around the end of the front plate 41 opposite the folded-back portion 43, so that the front plate 41 is formed in a dish shape having edges in cross section. In other words, the protruding step portion 44 and another protruding step portion 45 are formed on both sides of the flat base portion 411 of the front plate 41 in the width direction so as to rise on the opposite side to the back plate 42. The protruding step portions 44, 45 are each formed over the entire length of the front panel 41 in the longitudinal direction, and the distance between the protruding step portion 44 and another protruding step portion 45 approximately corresponds to the distance between a shape retaining material 521 at the edge of the lattice-shaped shape retaining body 52 described later and another shape retaining material 522 adjacent to it.

[0017] A front through hole 46 and a rear through hole 47, through which the core rod driving-in anchor 10 is inserted, are provided at corresponding positions approximately at the center of the flat base 411 of the front plate 41 and the center of the rear plate 42. In the clip-type retainer 40 of this example, the front through hole 46 is formed as a round hole whose diameter is smaller than the outer diameter of the core rod driving-in anchor 10 when expanded, and the rear through hole 47 is formed as an elongated hole that is long in the width direction of the anti-spare-off material 50, and the minor axis of the elongated rear through hole 47 is smaller than the outer diameter of the core rod driving-in anchor 10 when expanded. In other words, the front through hole 46 of the front plate 41 and the rear through hole 47 of the rear plate 42 are formed so that the core rod driving-in anchor 10 in the expanded state cannot slip out.

[0018] The planar anti-falling material 50 is composed of a net-like mesh sheet 51 and a lattice-like shape retaining body 52 that is overlaid and fixed on the mesh sheet 51, and the shape retaining body 52 is arranged and fixed at corresponding positions on both sides of the mesh sheet 51. The material and structure of the mesh sheet 51 and the shape retaining body 52 may be appropriate within an applicable range.

[0019] The peeling prevention material 50 is formed, for example, in a rectangular shape, and shape retaining materials 521 extending in the vertical direction of the shape retaining body 52 are provided along both end edges in the width direction, and another shape retaining material 522 extending in the vertical direction at a predetermined interval is provided inside the end edge shape retaining material 521. In the peeling prevention material 50 of this example, the end edge shape retaining materials 521-521 are arranged and fixed at corresponding positions on both sides of the mesh sheet 51, and the other shape retaining materials 522-522 are arranged and fixed at corresponding positions on both sides of the mesh sheet 51.

[0020] When constructing a spalling prevention structure on a concrete structure 100 using the core rod driving anchor 10 of the first embodiment, the clip-type retainer 40, and the spalling prevention material 50, the spalling prevention material 50 is laid so as to substantially follow the mounting surface 101 of the concrete structure 100. Then, holes 102 are formed with a drill at predetermined positions on the mounting surface 101 of the concrete structure 100 so as to penetrate the mesh sheet 51 of the spalling prevention material 50, and the clip-type retainer 40 is provided so as to sandwich the vicinity of both end edges in the width direction of the spalling prevention material 50 in a substantially U-shaped manner with the back panel 42 facing the mounting surface 101 (see FIG. 7).

[0021] At this time, clip-type presser 40 is positioned so that front through-hole 46 and rear through-hole 47 are positioned to correspond to perforation 102, and is positioned so that protruding step portion 44 of clip-type presser 40 accommodates shape retaining materials 521-521 at the widthwise edge of anti-peeling material 50, and protruding step portion 45 of clip-type presser 40 accommodates other shape retaining materials 522-522 near the inside of anti-peeling material 50. Furthermore, a plurality of clip-type pressers 40 are provided on each edge of anti-peeling material 50 at predetermined intervals in the length direction.

[0022] Before or after installing the clip-type retainer 40, the inside of the perforation 102 is cleaned and adhesive 30 is injected into the perforation 102 (see FIG. 7). Any suitable adhesive may be used for the adhesive 30 within the scope of the present invention, and it is preferable to use, for example, a two-liquid mixed type resin adhesive in which a thixotropic semi-liquid epoxy resin base agent and a semi-liquid polyamine hardener are mixed.

[0023] Thereafter, the core rod driving anchor 10 is inserted into the borehole 102 in which the uncured adhesive 30 exists, so that the front through-hole 46 and the rear through-hole 47 of the clip-type presser 40 communicate with each other, and the anchor is positioned so that the rear end 16 of the anchor body 11 is exposed from the borehole 102. At this time, as the core rod driving anchor 10 is inserted, the uncured adhesive 30 in the borehole 102 flows along the spiral groove 18 (see FIG. 7).

[0024] 8, the core rod 12 is hammered in to expand the expansion piece 14, and the expanded piece 14 is forced to bite into the wall of the borehole 102, thereby driving the core rod driving-in anchor 10 into the concrete structure 100 (see FIG. 8). By driving the core rod driving-in anchor 10 that penetrates the spalling prevention material 50 in an expanded state, the clip-type retainer 40 and the spalling prevention material 50 are temporarily fixed to the mounting surface 101.

[0025] 5, a washer 22 is inserted onto the male thread 17 of the core rod driving anchor 10, a nut 21 which is an anti-loosening nut is screwed onto the male thread 17 and tightened, the clip-type retainer 40 is pressed against the mounting surface 101 by the nut 21, and the pressed clip-type retainer 40 presses the shape retainer 52 against the mounting surface 101, thereby attaching the spalling prevention material 50 to the concrete structure 100. In other words, the projecting step portion 44 of the clip-type retainer 40 and the back plate 42 press the edge shape retainers 521-521 and the mesh sheet 51 so as to sandwich them, and the projecting step portion 45 of the clip-type retainer 40 and the back plate 42 press the other shape retainers 522-522 and the mesh sheet 51 so as to sandwich them, and in this state the spalling prevention material 50 is attached to the concrete structure 100, and a spalling prevention structure is constructed.

[0026] According to the core rod driving type anchor 10 of the first embodiment, the adhesive 30 is injected into the borehole 102 in advance, and when the core rod driving type anchor 10 is driven, the adhesive 30 is caused to flow along the spiral groove 18 on the outer periphery of the anchor body 11, so that the presence of the adhesive 30 can be prevented from hindering the insertion of the anchor into the borehole 102, and the core rod driving type anchor 10 can be reliably inserted smoothly into the borehole 102 into which the adhesive 30 has been injected. In addition, the adhesive 30 can be evenly rotated along the spiral groove 18 over the entire outer periphery forward of the rear end 16 of the anchor body 11. Then, the adhesive 30 that has been evenly rotated is caused to adhere to the unevenness of the spiral groove 18, so that the adhesive 30 in the borehole 102 can be sufficiently adhered over the entire outer periphery forward of the rear end 16 of the anchor body 11, and high anchor strength can be reliably exhibited. Therefore, the anchor can be fixed with high strength to a deeper portion embedded deeper than the surface portion of the concrete structure 100 which may become weak and collapse.

[0027] Furthermore, by expanding the expansion piece 14 and having it bite into the wall of the borehole 102, a fixing force with a relatively high anchor strength can be obtained even before the adhesive 30 hardens. Also, because the core rod driving-in anchor 10 can be cast with high anchor strength, it is possible to improve the attachment strength of the object to be attached to the concrete structure 100 using the core rod driving-in anchor 10 and to improve the stability of the installed state.

[0028] Furthermore, when the spiral groove 18 of the anchor body 11 is formed by rolling, it is possible to eliminate waste of material and reduce manufacturing costs. Furthermore, it is possible to form the spiral groove 18 in a short time, thereby improving production efficiency.

[0029] [Second embodiment of core rod driving anchor] 9, a core rod driving-in anchor 10a according to a first embodiment of the present invention is composed of a sleeve-shaped anchor body 11a and a core rod 12 inserted into the anchor body 11a, the configuration of the core rod 12 being the same as in the first embodiment. The anchor body 11a of this example is formed in a substantially cylindrical shape and is provided with a slit 13, an extension piece 14, and a step portion 15 similar to those in the first embodiment.

[0030] The rear end 16a of the anchor body 11a is formed in a rivet head shape, and a flange 192a is formed at the rear end of a smooth cylindrical surface 191a. A spiral groove 18 serving as a flow path for the adhesive 30 is formed on the entire outer periphery of the anchor body 11 in front of the rear end 16a, as in the first embodiment.

[0031] The core rod driving-in anchor 10a of the second embodiment is constructed in the same construction procedure as the first embodiment, up to the step of driving the core rod 12 in the core rod driving-in anchor 10 of the first embodiment with a hammer to expand the expansion piece 14, and driving the core rod driving-in anchor 10 into the concrete structure 100 so that the expansion piece 14 in the expanded state bites into the wall of the bored hole 102. Then, for example, the clip-type retainer 40 is pressed against the mounting surface 101 by the flange 192a, and the anchor is constructed.

[0032] According to the core rod driving type anchor 10a of the second embodiment, it is possible to obtain the corresponding effects from the configuration corresponding to that of the core rod driving type anchor 10 of the first embodiment.

[0033] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the inventions and embodiments listed as inventions, those specified by changing partial contents of these to other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects are obtained, and forming a higher-level concept. The inventions disclosed in this specification also include the following contents and modifications.

[0034] For example, the object to be attached to a concrete structure using the core rod driving anchor of the present invention is not limited to the clip-type retainer 40 and the spalling prevention material 50 in the above embodiment, and may be any appropriate object within the scope of the present invention. Furthermore, the adhesive used when installing the core rod driving anchor of the present invention is not limited to the above examples, and may be any appropriate object within the scope of the present invention. Furthermore, the core rod driving anchor of the present invention can be used by being driven into any appropriate concrete structure. [Industrial Applicability]

[0035] The core rod driving-in anchor of the present invention can be used, for example, when attaching an object to a concrete structure that has deteriorated with age or a concrete structure that has become weakened. [Explanation of symbols]

[0036] 10, 10a... Core rod driving anchor 11, 11a... Anchor body 12... Core rod 121... Tip 122... Sawtooth portion 13... Slit 14... Expansion piece 15... Step portion 16, 16a... Rear end 17... Male thread 18... Spiral groove 191a... Cylindrical surface 192a... Flange portion 21... Nut 22... Washer 30... Adhesive 40... Clip-type retainer 41... Front plate 411... Base 42... Rear plate 43... Folded portion 44... Projecting step portion 45... Another projecting step portion 46... Front through hole 47... Rear through hole 50... Anti-fall material 51... Mesh sheet 52... Shape retaining body 521, 522... Shape retaining material 100... Concrete structure 101... Mounting surface 102... Drilling T... Tunnel

Claims

1. The anchor is made up of a sleeve-shaped anchor body and a core rod inserted into the anchor body. The anchor body is provided with an expansion piece divided by a plurality of slits cut in the axial direction from the tip, The core rod is driven in and the tip of the core rod enters the step portion on the inside of the expansion piece, thereby expanding the expansion piece, A core rod driving type anchor, characterized in that a spiral groove serving as a flow path for an adhesive is formed over the entire outer periphery of the anchor body forward of the rear end portion.

2. 2. The core rod driving type anchor according to claim 1, wherein the spiral groove is formed by a rolling process.

3. A method for installing the core rod driving type anchor according to claim 1 or 2, A first step of injecting an adhesive into a hole formed in a concrete structure; a second step of inserting the core rod driving anchor into the borehole so that a rear end of the anchor body is exposed from the borehole, and causing the uncured adhesive to flow along the spiral groove; and a third step of driving the core rod into the hole to expand the expansion piece and cause the expansion piece to bite into the wall of the hole.

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