Foundation through-hole reinforcement tool and foundation through-hole reinforcement structure

Abstract

To provide a foundation through-hole reinforcement tool capable of reinforcing, with high strength and by a simple method, a through-hole located in a rising part of a ferroconcrete strip footing, and a foundation through-hole reinforcement structure in which an area around the through-hole in the rising part of the ferroconcrete strip footing is reinforced by the foundation through-hole reinforcement tool.SOLUTION: A foundation through-hole reinforcement tool 60 is installed over a pair of hole walls 16 facing each other with a gap to reinforce a through-hole 15 in a rising part 12 of a ferroconcrete strip footing 10, and comprises: a shaft-like strut 40; and a pair of pressure plates 50 that are fixed to both of the pair of hole walls 16 and provided with drop grooves 53 in which ends 42 and 43 of the shaft-like strut 40 are dropped.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a foundation through-hole reinforcing tool and a foundation through-hole reinforcing structure.

Background Art

[0002] In general, for example, the column base of a steel column is fixed via anchor bolts to the rising part of a fabric foundation made of reinforced concrete. In this rising part, through-holes such as manholes are generally provided. However, when anchor bolts for fixing the above-mentioned columns are arranged near this through-hole, a horizontal force during an earthquake acts on the anchor bolts, and when it acts on the rising part around the through-hole via the anchor bolts, there may arise a problem that the shear strength against the shear force caused by this horizontal force is insufficient.

[0003] For example, when a column constituting a shear wall with braces is located near a through-hole, a horizontal force during an earthquake acts on the braces as an axial force, and the horizontal component thereof acts on the anchor bolts, and the rising part of the foundation concrete bears (resists) this horizontal force. At this time, since there is a through-hole near the anchor bolts, if a sufficient end margin dimension for resisting the horizontal force is not ensured, horizontal conical failure is a concern.

[0004] Here, Patent Document 1 proposes a building foundation reinforcement method for reinforcing a foundation having an opening formed in a rising part. This building foundation reinforcement method includes a step of newly forming an opening in the rising part of the foundation or expanding an opening already formed in the rising part, a step of fitting and fixing a frame body inside the opening, and a step of detachably attaching a plate-like cover material for closing the inside of the frame body to the inside of the frame body.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the building foundation reinforcement method described in Patent Document 1, since it is necessary to perform construction in which a frame body is fitted and fixed to an opening formed in the rising portion of the foundation, particularly when reinforcing a through hole (here, an opening) in the rising portion of an existing structure, it becomes a relatively large-scale construction in a narrow underfloor space, making the construction extremely difficult.

[0007] The present invention has been made in view of the above problems, and provides a foundation through-hole reinforcement tool that enables high-strength reinforcement of a through hole in the rising portion of a fabric foundation made of reinforced concrete by a simple method, and a foundation through-hole reinforcement structure in which the periphery of the through hole in the rising portion of the fabric foundation is reinforced by the foundation through-hole reinforcement tool.

Means for Solving the Problems

[0008] To achieve the above object, one aspect of the foundation through-hole reinforcement tool according to the present invention is a foundation through-hole reinforcement tool that is installed across a pair of opposing hole walls with a gap therebetween in a through hole in the rising portion of a fabric foundation made of reinforced concrete to reinforce the through hole, an axial tension member, and a pair of bearing plates fixed to both of the pair of hole walls and having drop grooves into which the ends of the tension member are dropped.

[0009] According to this aspect, the foundation through-hole reinforcing tool has a shaft-shaped main material and a pair of pressure plates that are fixed to both of the pair of hole walls and have recessed grooves into which both ends of the main material are dropped. Thus, the foundation through-hole reinforcing tool can be easily attached across the pair of opposing hole walls of the through-hole, and this foundation through-hole reinforcing tool can serve as a tension bar that reinforces the through-hole and counteracts the shear force acting on the periphery of the through-hole. More specifically, for example, when reinforcing the through-holes in the rising portions of an existing fabric foundation, an operator only needs to hold the foundation through-hole reinforcing tool and move under the floor, and then install the foundation through-hole reinforcing tool with respect to the through-holes to be reinforced. Therefore, the attachability is good not only for a newly installed fabric foundation but also for an existing fabric foundation.

[0010] Further, by adjusting the area of the pair of pressure plates (the area in contact with the hole wall), the pressure applied from the tension member can be made to act, for example, over the entire area of the hole wall, and it is possible to prevent the occurrence of a region where the pressure does not act on the hole wall and where shear failure is likely to occur.

[0011] Also, when it is desired to use the through-hole as a manhole (person access opening), since the foundation through-hole reinforcing tool can be easily removed from the through-hole, and after an operator or the like has passed through the through-hole, the foundation through-hole reinforcing tool can be reinstalled in the through-hole, the foundation through-hole reinforcing tool does not become an obstacle when using the through-hole.

[0012] Another aspect of the foundation through-hole reinforcing tool according to the present invention is wherein the pressure plate is a joining plate of a first plate that abuts against the hole wall and a second plate that has the recessed groove, and is characterized in that.

[0013] According to this aspect, since the pressure plate is a joining plate (a plate joined by welding or the like) of a first plate that abuts against the hole wall and a second plate that has the recessed groove, the manufacturability of the pressure plate is improved.

[0014] Another aspect of the foundation through-hole reinforcing tool according to the present invention is wherein the pressure plate is It has a first plate that abuts against the hole wall and a plurality of block protrusions joined to the first plate, and the plurality of block protrusions are arranged at positions separated from each other to form the drop groove.

[0015] According to this aspect, the bearing plate has a first plate that abuts against the hole wall and a plurality of block protrusions joined to the first plate, and the plurality of block protrusions are arranged at positions separated from each other to form a drop groove. As a result, the strut can be laterally moved from the side where there are no block protrusions, and the end of the strut can be dropped into the drop groove. Conversely, the end of the strut can be lifted from the drop groove, laterally moved, and removed. This improves the attachability and detachability of the strut in a narrow underfloor space.

[0016] Also, in another aspect of the foundation through-hole reinforcement tool according to the present invention, Above the bearing plate, a first overhanging piece that projects laterally and is placed on the top end of the rising part is attached. On the left and right sides of the bearing plate, a pair of second overhanging pieces that project laterally and face the left and right side surfaces of the rising part are respectively attached. A bolt hole is formed in one of the second overhanging pieces, and a push bolt passes through the bolt hole while being screwed into it, and its tip presses against the side surface of the rising part.

[0017] According to this aspect, the bearing plate includes a first overhanging piece placed on the top end of the rising part and a pair of second overhanging pieces facing the left and right side surfaces of the rising part. The tip of the push bolt passing through the bolt hole of one of the second overhanging pieces presses against the side surface of the rising part, so that the bearing plate can be securely attached to three surfaces (the top end and a pair of side surfaces) of the rising part.

[0018] Also, another aspect of the foundation through-hole reinforcement tool according to the present invention is when the hole wall is an inclined surface inclined in the through direction of the through-hole Among the pressure - supporting plates, the wide - width surface that abuts against the inclined surface is an inclined surface complementary to the inclined surface, and the other wide - width surface is a surface parallel to the penetration direction.

[0019] According to this aspect, when the hole wall is an inclined surface inclined in the penetration direction of the through - hole, the wide - width surface of the pressure - supporting plate that abuts against the inclined surface is an inclined surface complementary to the inclined surface, and the other wide - width surface is a surface parallel to the penetration direction. Thus, while ensuring that the pressure - supporting plate abuts against the inclined surface of the hole wall, the opposing surfaces of the pair of pressure - supporting plates are made to face each other, and both ends of the tension member can be correctly dropped into the pair of recessed grooves.

[0020] Also, in another aspect of the foundation through - hole reinforcing tool according to the present invention, the tension member has a shaft - shaped main body, a contact plate at one end of the main body, which is accommodated in the recessed groove of one of the pressure - supporting plates, and has a length - adjusting bolt that is screwed into a screw groove at the other end of the main body to adjust the length of the tension member, and the head of which is accommodated in the recessed groove of the other pressure - supporting plate.

[0021] According to this aspect, since the tension member is provided with a contact plate at one end of the shaft - shaped main body and a length - adjusting bolt is screwed into the screw groove at the other end, by adjusting the protruding length of the length - adjusting bolt from the other end of the main body, the tension member can be installed between the pair of pressure - supporting plates in a desired tension posture.

[0022] Also, one aspect of the foundation through - hole reinforcing structure according to the present invention is characterized in that the foundation through - hole reinforcing tool is installed across a pair of hole walls facing each other with a gap in a through - hole in the rising part of a fabric foundation made of reinforced concrete.

[0023] According to this aspect, since the foundation through-hole reinforcing tool of the present invention is formed by being easily attached across a pair of opposing hole walls of the through-hole, the foundation through-hole reinforcing tool serves as a tension rod that reinforces the through-hole, and it is possible to efficiently form a reinforcing structure in which cone failure is effectively suppressed against the shear force acting around the through-hole. This reinforcing structure can be formed not only for a newly constructed fabric foundation but also for an existing fabric foundation. In particular, it exhibits a remarkable effect when reinforcing the through-holes of an existing fabric foundation, which is generally extremely difficult to construct.

[0024] Moreover, another aspect of the foundation through-hole reinforcing structure according to the present invention is characterized in that an anchor bolt for fixing a column or the column base of a column constituting a shear wall is embedded on the side of the through-hole in the rising portion.

[0025] According to this aspect, even in a form in which an anchor bolt for fixing the column base of a column is embedded on the side of the through-hole in the rising portion, by installing the foundation through-hole reinforcing tool of the present invention across a pair of opposing hole walls of the through-hole, it is possible to effectively suppress cone failure caused by the shear force acting around the through-hole.

Effects of the Invention

[0026] As can be understood from the above description, according to the foundation through-hole reinforcing tool and the foundation through-hole reinforcing structure of the present invention, the through-holes in the rising portion of a fabric foundation made of reinforced concrete can be reinforced with high strength by a simple method.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiment for Carrying Out the Invention

[0028] Hereinafter, an example of the foundation through-hole reinforcement tool and the foundation through-hole reinforcement structure according to the embodiment will be described with reference to the accompanying drawings. In the present specification and drawings, substantially the same components may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[0029] [Foundation Through-Hole Reinforcement Tool and Foundation Through-Hole Reinforcement Structure According to Embodiment] With reference to FIGS. 1 to 4, an example of the foundation through-hole reinforcement tool and the foundation through-hole reinforcement structure according to the embodiment will be described. Here, FIG. 1 is a front view showing a mat foundation having a through-hole in which the foundation through-hole reinforcement tool according to the embodiment is installed, together with a part of a shear wall. FIG. 2 is an exploded perspective view of an example of the foundation through-hole reinforcement tool according to the embodiment, and FIG. 3 is a perspective view showing another example of the bearing plate. Further, FIG. 4 is a front view of an example of the foundation through-hole reinforcement structure according to the embodiment.

[0030] The reinforced concrete mat foundation 10 shown in FIG. 1 is an existing mat foundation having a footing 11 and a rising portion 12, and a through-hole 15 serving as a manhole is provided in a part of its side surface 14. Here, the mat foundation may be a newly constructed one, but in the case of an existing mat foundation as in the illustrated example, the effect is more remarkable because a smooth foundation through-hole reinforcement structure can be formed in a narrow underfloor space.

[0031] On the top end 13 of the rising portion 12 of the mat foundation 10, a base plate 23 at the column foot 22 of a pair of steel-frame columns 21A and 21B forming the shear wall 20 is placed, and the base plate 23 is fixed to the mat foundation 10 by a plurality of anchor bolts 24.

[0032] Gusset plates 25 are welded to the column bases 22 of the pair of columns 21, and the respective ends of the pair of braces 27 are bolted to the gusset plates 25. That is, the shear wall 20 has a pair of steel columns 21 and a pair of braces 27, and the top ends of the pair of columns 21 are bolted, for example, to a steel beam (not shown).

[0033] As shown in FIG. 1, among the plurality of anchor bolts 24 that fix the base plate 23 at the column base 22 of the column 21A on the right side, the anchor bolt 24A on the through-hole side is close to the through-hole 15.

[0034] Due to the horizontal force H during an earthquake acting on the shear wall 20, an axial force N2, which is a tensile force, is generated in the brace 27, and the horizontal component Q of the axial force N2 acts as a shear force on the rising portion 12 via the anchor bolt 24A.

[0035] As in the illustrated example, when the anchor bolt 24A and the through-hole 15 are close to each other, a conical failure surface extending obliquely downward at 45° from the top end position of the anchor bolt 24A can be formed due to the shear force Q.

[0036] Therefore, by installing the foundation through-hole reinforcement tool 60 (see FIG. 2 etc.) across the pair of hole walls 16 facing the through-hole 15, the foundation through-hole reinforcement tool 60 becomes a tension bar that reinforces the through-hole 15, and a foundation through-hole reinforcement structure 100 (see FIG. 4) capable of preventing conical failure can be formed against the shear force Q acting on the periphery of the through-hole 15.

[0037] In addition, in FIG. 1, a part of the existing floor material 30 is shown, and the floor material 30 is supported by a plurality of bundles 35. Therefore, when reinforcing the existing through-hole 15, a worker enters below the floor material 30 and accesses the through-hole 15 to be reinforced through the through-hole 15 provided in each cloth foundation 10 to form a reinforcement structure. Therefore, there are restrictions on the working space, and the reinforcement construction of the through-hole 15 can generally be extremely difficult.

[0038] As shown in FIG. 2, the foundation through-hole reinforcement tool 60 installed in the through-hole 15 includes a shaft-shaped and steel tension member 40, and a pair of bearing plates 50 that are fixed to both of the pair of hole walls 16 and have drop grooves 53 into which both ends of the tension member 40 are dropped.

[0039] The tension member 40 has a shaft-shaped and columnar main body 41, and a disk-shaped contact plate 44 having a larger planar dimension than the main body 41 is provided at one end 42 thereof. Here, the main body 41 may be a polygonal column such as a square column or a hexagonal column in addition to the columnar shape shown in the illustrated example.

[0040] The contact plate 44 at one end 42 of the main body 41 is dropped into the drop groove 53 of one bearing plate 50 fixed to the hole wall 16 in the X1 direction.

[0041] On the other hand, a thread groove 45 is provided at the other end 43 of the main body 41, and a length adjustment bolt 47 is screwed into the thread groove 45. By turning the length adjustment bolt 47 to adjust the protruding length from the end 43 in the X3 direction, the overall length of the tension member 40 can be adjusted. The head nut 48 of the length adjustment bolt 47 is dropped into the drop groove 53 of the other bearing plate 50 fixed to the hole wall 16 in the X2 direction.

[0042] In addition, a lock nut 46 is fixed around the thread groove 45 at the other end 43 of the main body 41 to suppress the movement (loosening) of the length adjustment bolt 47 with the adjusted length.

[0043] The bearing plate 50 is a joined plate in which a steel first plate 51 that abuts against the hole wall 16 and a steel second plate 52 having a drop groove 53 are welded.

[0044] The pair of hole walls 16 of the through hole 15 shown in FIG. 1 have inclined surfaces that are not parallel to the through direction but are inclined. Therefore, the wide surface in the first plate 51 that abuts against the hole wall 16 is also an inclined surface 51a complementary to the inclined surface of the hole wall 16, and the other wide surface is a surface parallel to the through direction. Since the second plate 52 is fixed to this other wide surface, the opposing surfaces 52a of the pair of second plates 52 are parallel surfaces that are parallel to each other, and both ends of the axial tension member 40 can be easily dropped into both of the recessed grooves 53. Here, when the hole wall 16 does not have an inclined surface, a first plate without an inclined surface is applied.

[0045] Above the first plate 51, a first projecting piece 55 that projects laterally and is placed on the top end 13 of the rising portion 12 is attached, and on the left and right sides of the first plate 51, a pair of second projecting pieces 57 that project laterally and face the left and right side surfaces 14 of the rising portion 12 are respectively attached.

[0046] Also, a bolt hole 57a is formed in one of the second projecting pieces 57, and a push bolt 58 penetrates in the X5 direction while being screwed into the bolt hole 57a, and its tip presses against the side surface 14 of the rising portion 12.

[0047] By bringing the first plate 51 into contact with the hole wall 16, placing the first projecting piece 55 on the top end 13, opposing the pair of second projecting pieces 57 to the two side surfaces 14, and screwing in the push bolt 58 to press its tip against one of the side surfaces 14, the support pressure plate 50 can be fixed immovably in such a manner that substantially the entire vertical surface (a surface extending in the vertical direction) of the hole wall 16 is covered by the support pressure plate 50.

[0048] In this way, the support pressure plate 50 can be firmly and easily attached to the hole wall 16, and the removal of the support pressure plate 50 from the hole wall 16 can also be easily performed by a method opposite to the attachment method.

[0049] Here, as the bearing plate, other examples shown in FIG. 3 may be applied. The bearing plate 50A in the illustrated example has a first plate 51 that abuts against the hole wall 16 and a plurality (three in the illustrated example) of block protrusions 59 joined to the first plate 51. The plurality of block protrusions 59 are arranged at positions separated from each other, and a drop groove 59A is formed inside them.

[0050] By applying the bearing plate 50A, the strut 40 can be laterally moved in the X7 direction using the upper region where the block protrusions 59 do not exist, and the end of the strut 40 can be dropped into the drop groove 59A in the X8 direction. Therefore, even when it is difficult to drop the end of the strut 40 from above by a large pull or the like that supports the floor, it is preferable that the strut 40 can be installed while being laterally moved.

[0051] After attaching the bearing plates 50 to the pair of hole walls 16 respectively, while adjusting the overhanging length of the length adjustment bolt 47, both ends of the strut 40 are dropped into the pair of drop grooves 53, and the length adjustment bolt 47 is further adjusted so that the pair of bearing plates 50 are pressed by the strut 40. Thus, as shown in FIG. 4, the installation of the foundation through-hole reinforcing tool 60 for the through-hole 15 is completed, and the foundation through-hole reinforcing structure 100 is formed.

[0052] In this way, even in a narrow under-floor space, the worker can carry the pair of bearing plates 50 and the strut 40 to the through-hole 15, easily attach the bearing plates 50 to the pair of hole walls 16 respectively, drop both ends of the length-adjusted strut 40 into the drop grooves 53 of the pair of bearing plates 50, and complete the installation of the foundation through-hole reinforcing tool 60. Therefore, the foundation through-hole reinforcing tool 60 can be installed with good attachability, and the foundation through-hole reinforcing structure 100 can be formed.

[0053] When an operator passes through the through-hole 15 during inspection of the underfloor space or the like, the entire basic through-hole reinforcement tool 60 or only the strut member 40 can be easily removed from the through-hole 15. After the operator passes through the through-hole 15, the basic through-hole reinforcement tool 60 can be easily reinstalled with respect to the through-hole 15.

[0054] According to the basic through-hole reinforcement structure 100, since the basic through-hole reinforcement tool 60 is attached across a pair of opposing hole walls 16 of the through-hole 15 and the strut member 40 serves as a strut bar for reinforcing the through-hole 15, it becomes a reinforcement structure in which cone failure is effectively suppressed against the shear force Q acting on the periphery of the through-hole 15.

[0055] At this time, since the bearing plate 50 is in contact with substantially the entire vertical surface of the hole wall 16, the bearing pressure (reaction force of the shear force Q) received from the strut member 40 acts on substantially the entire vertical surface of the hole wall 16, and the occurrence of cone failure in the region where the bearing pressure does not act is prevented. For example, when the bearing pressure acts only on a part of the hole wall 16, cone failure in the region where the bearing pressure acts is suppressed, while in the region where the bearing pressure does not act, there is a risk of cone failure due to the acting shear force, which is not preferable.

[0056] In addition, other embodiments in which other components are combined with the configurations and the like described in the above embodiments may be used, and the present invention is not limited to the configurations shown here at all. In this regard, it can be changed without departing from the gist of the present invention, and can be appropriately determined according to the application form.

Explanation of Reference Numerals

[0057] 10: Fabric foundation 11: Footing 12: Upright portion 13: Top end 14: Side surface 15: Through-hole 16: Hole wall 20: Shear wall 21: Column 22: Column base 23: Base plate 24: Anchor bolt 25: Gusset plate 27: Brace 30: Floor material 35: Bundle 40: Strut 41: Body (axial body) 42: One end (end part) 43: The other end (end part) 44: Fitting plate 45: Thread groove 46: Lock nut 47: Length adjustment bolt 48: Head nut 50: Bearing plate 51: First plate 51a: Tapered surface 52: Second plate 52a: Parallel surface (opposing surface) 53: Recess groove 55: First protruding piece 56,57: Second protruding piece 57a: Bolt hole 58: Pressing bolt 59: Block protrusion 59A: Recess groove 60: Foundation through-hole reinforcement tool 100: Foundation through-hole reinforcement structure H: Horizontal force N: Axial force Q: Shearing force

Claims

1. A foundation through-hole reinforcing tool that is installed across a pair of opposing hole walls with a gap therebetween in a through-hole in the rising portion of a fabric foundation made of reinforced concrete to reinforce the through-hole, comprising: a shaft-shaped strut member; a pair of bearing plates fixed to both of the pair of hole walls and having drop grooves into which the ends of the strut member are dropped, characterized in that the foundation through-hole reinforcing tool has the pair of bearing plates.

2. The bearing plate is a joint plate of a first plate that abuts against the hole wall and a second plate that has the drop groove, and the foundation through-hole reinforcing tool according to claim 1, characterized in that the bearing plate is the joint plate.

3. The bearing plate is a first plate that abuts against the hole wall and a plurality of block protrusions joined to the first plate, and the plurality of block protrusions are arranged at positions separated from each other to form the drop groove, and the foundation through-hole reinforcing tool according to claim 1, characterized in that the bearing plate has the plurality of block protrusions.

4. Above the bearing plate, a first overhanging piece that overhangs laterally and is placed on the top end of the rising portion is attached, On the left and right sides of the bearing plate, a pair of second overhanging pieces that overhang laterally and face the left and right side surfaces of the rising portion are respectively attached, A bolt hole is formed in one of the second overhanging pieces, and a push bolt penetrates while being screwed into the bolt hole, and the tip thereof presses the side surface of the rising portion, and the foundation through-hole reinforcing tool according to claim 1, characterized in that the push bolt is arranged as described above.

5. When the hole wall is an inclined surface inclined in the through direction of the through-hole, Among the bearing plates, the wide surface that abuts against the inclined surface is an inclined surface complementary to the inclined surface, and the other wide surface is a surface parallel to the through direction, and the foundation through-hole reinforcing tool according to claim 1, characterized in that the bearing plate has such inclined surfaces.

6. The strut member is a shaft-shaped main body; a contact plate at one end of the main body and housed in the drop groove of one of the bearing plates; A length adjustment bolt that is screwed into a screw groove at the other end of the main body to adjust the length of the strut member and the head of which is housed in the drop groove of the other bearing plate, and the foundation through-hole reinforcing tool according to claim 1, characterized in that the strut member has the length adjustment bolt.

7. In the through-hole in the rising part of the reinforced concrete strip foundation, the foundation through-hole reinforcement tool according to any one of claims 1 to 6 is installed across a pair of hole walls facing each other with a gap therebetween, and the foundation through-hole reinforcement structure is characterized by this.

8. The foundation through-hole reinforcement structure according to claim 7, characterized in that an anchor bolt for fixing a column or the column base of a column constituting a shear wall is embedded on the side of the through-hole in the rising part.

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