JP5006742B2 - Assembly type formwork and anchor bolt expansion method using the same - Google Patents

Description

  In the present invention, when a structural column is newly set up on a concave portion at the top end of a rising wall of a reinforced concrete foundation under a floor of an existing building or a similar portion, a column base is fixed to the concave portion. The present invention relates to a method for expanding an anchor bolt and a formwork for placing additional concrete in the recess in the method.

  For existing buildings such as houses, change the internal layout (partition walls, etc.) and remodeling work to reinforce the structure for extension and renovation, change the structural type (wooden, steel, RC, etc.) Regardless, there is an increasing number of works in which anchor bolts are newly installed on existing foundations and beams and pillars are erected after structural design using structural calculations to ensure structural safety. Patent Document 1 discloses a method in which a column base concrete is newly placed on a foundation beam, an anchor bolt is installed on the column base concrete, and a steel column base is fixed to the anchor bolt. . Patent Documents 2 and 3 disclose a form for anchor bolt embedding.

JP-A-6-65931 JP-A-7-166702 JP-A-8-4285

  By the way, the foundation of an existing building is composed of a reinforced concrete continuous cloth foundation with a cross-sectional shape of an inverted T-shape, and the top end (base top end) of the rising wall of the foundation is usually at a predetermined position for underfloor ventilation. A recess serving as a ventilation opening is formed. In such extension and renovation of a building, when a new pillar is set up on such a recess, it is confirmed by structural calculation that the building after the extension and renovation satisfies a predetermined structural strength standard. It is desirable to perform extension and renovation work using pillars that have the same specifications and dimensions. However, since this column is placed on the top of the foundation and fixed with bolts, the length of the column is insufficient by the depth of the recess. For this reason, it is necessary to newly place concrete in the recess and to install anchor bolts on the additional concrete.

  However, in the method of Patent Document 1 described above, in order to place concrete in the concave portion, a mold frame surrounding the concave portion is necessary. For that purpose, a floor plate made of a concrete panel or the like is removed extensively or an operator needs It was necessary to make an opening space for the floorboard that could be worked under the floor, and it was also necessary to repair the floorboard that was removed after the pillar was erected, and the work was complicated.

  In addition, both of the molds of Patent Documents 2 and 3 are installed in advance at the time of new construction, and when used for renovation, it is necessary to remove the floorboard over a wide range.

  It is an object of the present invention to minimize the area that breaks an existing floor board and to easily add an anchor bolt when a structural column is newly set up on a recess of an existing foundation in a renovation of an existing building. It is to provide a method.

The first of the present invention is a prefabricated formwork for placing additional concrete in a concave portion of a concrete foundation under the floor,
It consists of a pair of end molds and a pair of side molds,
The end formwork has an upright plate in contact with the side surface of the recess, and a bottom plate extending in the horizontal direction from the lower end of the upright plate and in contact with the bottom surface of the recess,
The side mold has an upright plate, a bottom plate extending in the horizontal direction from the lower end of the upright plate and in contact with the bottom surface of the recess, and a pair of side plates that overlap the upright plate and slide in the horizontal direction. ,
Standing plate connection that connects the left and right ends of the upright plate of the end formwork and the portions that become the left and right ends of the formwork when the pair of side plates of the side formwork are slid left and right respectively. Part is provided,
The left and right ends of the bottom plate of the end mold and the left and right ends of the bottom plate of the side mold are provided with bottom plate connecting portions that are connected to each other.

In the assembly formwork of the present invention, the following configuration is included as a preferred embodiment.
The standing plate and the bottom plate of the end form frame are configured to be foldable by a hinge portion.
The side mold has an engaging plate that overlaps the upright plate with a predetermined gap above and below the upright plate, and the side plate is slidably fitted in the gap between the upright plate and the engaging plate.
At least one of the upright plate connecting portion and the bottom plate connecting portion is constituted by a claw and a hole, and the claw is loosely fitted in the hole.
Openings are formed in the upright plate and the bottom of the end mold.
The upright plate of the end mold has a folded piece extending from the left and right ends in a direction perpendicular to the upright plate, and the bottom plate has a folded piece extending vertically upward from the left and right ends.

The second of the present invention is an anchor bolt expansion method for standing a structural column in a concave portion of a concrete foundation under the floor,
In the floor slab, a column-base opening is formed at the position where the structural column is erected to expose a part of the concave portion of the concrete foundation,
Inserting the end formwork and the side formwork of the assembly formwork of the present invention from the opening, respectively, assembling the formwork under the floor slab and installing it in the recess,
Attach the anchor bolt to the bottom of the recess from the opening, and fix it.
The additional concrete is placed in the above-mentioned formwork.

  The assembly mold according to the present invention simply connects the end mold and the side mold at the connecting portion, and can be easily assembled even in a narrow space. In addition, since the side mold can change the left and right lengths by sliding the side plate, it can easily cope with the variation in the length of the corresponding recess. Further, by providing openings on the upright plate and the bottom plate of the end formwork, it is possible to secure a sufficient ground contact surface between the existing concrete and the additional concrete. Furthermore, the present invention can be applied when the width of the expanded concrete is larger than the width of the foundation concrete.

  Therefore, in the method for adding anchor bolts according to the present invention, it is only necessary to provide a floor slab constituted by a floor plate with a minimum opening that allows the end mold and the side mold to pass through. There is no risk of removing and affecting the internal structure of the surrounding area. In addition, repair work after work is greatly reduced. Furthermore, the opening can be formed with a generally used horuseau, and no large-scale equipment is required. As a result, since the construction range is small, work efficiency is good, and anchor bolts can be added in a short time and at low cost.

  Therefore, according to the present invention, in the renovation of an existing building, it is possible to greatly reduce problems such as cost increase related to the addition of anchor bolts when a column is erected in the recess of the foundation, and extension of the construction period. Since it is not necessary to avoid the concave portion as a position where the column is erected, a remodeling design with a high degree of freedom can be performed.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention.

  FIG. 1 is a perspective view showing components of one embodiment of the assembly mold according to the present invention, wherein (a) is an end mold and (b) is a side mold. In the present invention, a pair of end molds 2 and side molds 3 are used, and the molds are arranged facing each other to form a box shape having an open top. 2A shows a state in which the side mold 3 is connected to the end mold 2, and FIG. 2B is a completed drawing.

  The end formwork 2 according to the present invention includes an upright plate 11 that is in contact with a side surface of a concave portion of an existing concrete foundation when an additional concrete is placed, and a bottom plate that extends horizontally from the lower end of the upright plate 11 and contacts the bottom surface of the concave portion. 12 and has a structure capable of self-supporting.

  In this example, the upright plate 11 and the bottom plate 12 are integrated by the hinge member 4 and can be folded to reduce the bulk by the end mold 2 as shown in FIG. Therefore, after manufacturing the end mold 2, no space is required in the folded state, and it can be put under the floor through a narrow opening as described later.

  As the hinge member 4, a commercially available hinge may be used, but the end plate 2 may be folded after manufacturing and the upright plate 11 and the bottom plate 12 may be integrated until it is expanded at the time of assembly. Since it will be embedded in, it can be a simple structure. For example, a hinge member according to the present invention can be obtained by attaching a thin metal piece with a perforation in the center so as to divide the rectangle into two parts and attaching it to a predetermined position by welding, bonding with an adhesive, screwing, etc. 4 can be fulfilled.

  In this example, an opening is formed in the upright plate 11 and the bottom plate 12 in order to secure a joint surface in which the installed additional concrete is in direct contact with the existing concrete foundation. The opening is preferably formed as wide as possible within the range allowed by the strength of the upright plate 11 and the bottom plate 12, but as described above, when opening the folded upright plate 11 and the bottom plate 12, a narrow opening is formed. It is necessary to leave the plate members of the upright plate 11 and the bottom plate 12 in an appropriate position so that the operator can easily open from the part. In this example, the frame portion 11a at the upper end of the opening portion of the upright plate 11 is formed at a position slightly lowered downward from the uppermost end of the upright plate 11, so that the end of the work is limited in the underfloor space where freedom of work is restricted. When the raised upright plate 11 of the partial mold 2 is opened and raised, it can be performed without touching the lower surface of the floor slab, thereby making the operation easier. Moreover, the opening part of the baseplate 12 needs to provide an opening part in the attachment position of an anchor bolt at least so that the baseplate 12 may not interfere with the anchor bolt attached to a recessed part bottom face after installing the said formwork in a recessed part.

  The side surface formwork 3 according to the present invention includes an upright plate 32, a bottom plate 33 that extends in the horizontal direction from the lower end of the upright plate 32, and comes into contact with the bottom surface of the concave portion of the existing concrete foundation when the additional concrete is placed. It has a pair of side plates 31a and 31b that overlap each other and can slide in the horizontal direction. As will be described later, when the width of the expanded concrete is wider than the width of the foundation, the bottom plate 33 forms the bottom of the expanded portion protruding from the foundation, and the concrete cast from the lower end side of the upright plate 32 leaks. In order to prevent it from coming out, it is further provided to reinforce the lower end of the upright plate 32, but it is preferable to form it with a minimum area so as not to interfere with the anchor bolt attached to the bottom surface of the recess.

  In this example, a folded piece 32a extending outward is provided at the upper end of the upright plate 32. This is a part for attaching an engagement piece 5 described later to the upper end of the upright plate 32. It also has a role to reinforce the top edge.

  In this example, engagement plates 5 and 6 are attached to the up and down sides of the upright plate 32 via a predetermined gap, and the side plates 31a and 31b are connected to the upright plate 32 and the engagement plate 32, respectively. 5 and 6 are loosely fitted into the gap. As shown in FIG. 3B, the side plates 31a and 31b can be reduced in volume by sliding to the center and overlapping each other. Therefore, after manufacturing the side mold 3, the side plates 31a and 31b and the upright plate 32 are overlapped to save space, and can be put under the floor through a narrow opening as described later. .

  The end mold 2 and the side mold 3 according to the present invention are formed by sliding the left and right ends of the upright plate 11 of the end mold 2 and the pair of side plates 31a and 31b of the side mold 3 to the left and right, respectively. In this case, upright plate connecting portions that are connected to each other are provided at the left and right ends of the mold 3. As a specific configuration of the upright plate connecting portion, a combination of a claw and a hole in which the claw can be loosely fitted is preferable. In this example, a hole 10 is formed at the left and right ends of the upright plate 11 on the end mold frame 2 side. 2, and claw 9 is provided at the end of each of the side plates 31 a and 31 b on the side mold 3 side, and the claw 9 is loosely fitted into the hole 10 as shown in FIG. Thus, the upright plate 11 of the end mold 2 and the side plate 31a of the side mold 3 are connected to each other. In addition, the hole 10 is formed in the position corresponding to the nail | claw 9 so that the nail | claw 9 can be loosely fitted with the length which has allowances up and down of the nail | claw 9.

  Further, in the present invention, bottom plate connecting portions that are connected to each other are provided on the left and right ends of the bottom plate 12 of the end mold 2 and the left and right ends of the bottom plate 33 of the side mold 3 respectively. As a specific configuration of the bottom plate connecting portion, a combination of a claw similar to the upright plate connecting portion and a hole in which the claw can be loosely fitted is preferable. In this example, the bottom plate 12 has a bottom plate 12 side thereof. Holes 8 are provided at the left and right ends, claw 7 is provided at the left and right ends of the bottom plate 33 on the side mold 3 side, and the claw 7 is loosely fitted into the holes 8 so that the end portions as shown in FIG. The bottom plate 12 of the mold 2 and the bottom plate 33 of the side mold 3 are connected to each other. Further, the hole 8 needs to be formed at a position corresponding to the nail 7 so as to allow the nail 7 to be loosely fitted, with a sufficient length on the left and right of the nail 7, but longer than that. Thus, an adjustment allowance can be given to the distance between the upright plate 32 and the end mold 2, that is, the distance between the end molds 2 at the time of assembly, and the error in the shape and size of the corresponding recess, etc. The distance can be changed in response to.

  In this example, the claws 7 and 9 both protrude toward the outside of the mold. Accordingly, the claws 7 and 9 need to be formed at positions where they do not interfere with the foundation surface. However, as will be described later, when the expanded concrete is wider than the foundation, the claws 7 and 9 In this case, the claws 7 and 9 protruding outward are positioned so as to sandwich the foundation, as will be described later. It is possible to prevent the formwork from shifting in the width direction of the foundation. Therefore, even if the width of the foundation is sufficient and it is not necessary to make the width of the expanded concrete wider than the width of the foundation, the expanded concrete can be reliably placed in the recess by deliberately designing it.

  Further, in order to make the claws 7 and 9 protrude toward the inside of the mold, claw is formed on the upper surface of the bottom plate 12 of the end mold 2 and the holes for loosely fitting the claws are formed on the side mold 3. The bottom plate 33 may be provided. In FIG. 2 (a), the bottom plate 33 of the side mold 3 is on the bottom plate 12 of the end mold 2, but this is reversed to form claws on the upper surface of the bottom plate 33. A configuration in which the claw is loosely fitted into the hole 8 from below 12 may be employed. Further, in the upright plate connecting portion, the left and right ends of the upright plate 11 are provided with claws at a predetermined distance from the end sides, and the folded pieces that extend inward are provided on the end sides of the side plates 31a and 31b, It can be set as the structure which provided the hole which loosely fits the nail | claw provided in the said standing board 11 in this folding piece.

  In this example, the folded piece 13 extending from the left and right ends of the upright plate 11 of the end mold 2 in the direction perpendicular to the upright plate 11, and the folded piece 14 extending from the left and right ends vertically upward to the bottom plate 12, respectively. Provided. These folded pieces 13 and 14 have an action of reinforcing the upright plate 11 and the bottom plate 12, and from the gap between the upright plate 11 and the side plates 31a and 31b, and the gap between the bottom plate 12 and the side plates 31a and 31b. It is possible to prevent the added concrete from leaking out. In addition, the bottom plate connecting portion and the upright plate connecting portion are reinforced, and the expansion of the expanded concrete can be reliably prevented.

  In this example, since the folded piece 14 is provided on the bottom plate 12, an attachment portion that extends in the horizontal direction from the lower end of the upright plate 11 by the height of the folded piece 14 so that the folded piece 14 does not get in the way when folded. 11b is formed, the bottom portion 12 is arranged on the extension of the attachment portion, the hinge member 4 provided with a perforation at the center of the rectangular metal plate, one of the perforations as the center and the other of the attachment portion 11b. An example of welding to the bottom plate 12 is shown. In the present invention, when the folded piece 14 is not provided, the attachment portion 11 b is not necessary, and the hinge member 4 may be directly attached to the lower end of the upright plate 11.

  As shown in FIG. 2, the end mold 2 and the side mold 3 according to the present invention are connected to each other by the upright plate connecting portion and the bottom plate connecting portion, so that the upper side shown in FIG. Can be assembled into an open box.

  Next, the method for adding anchor bolts according to the present invention will be described by taking as an example the case of using the assembly formwork shown in FIGS.

  FIG. 4 shows a recess formed at the top end of a rising wall of a foundation 40 which is a reinforced concrete continuous cloth foundation having a reverse T-shaped cross-section consisting of a base that contacts the ground surface to which the present invention is applied and a wall rising from the base. In the figure, 41 is the bottom surface of the recess, and 42 is the side surface. For convenience, the floor slab is omitted. Hereinafter, each process is demonstrated using FIGS.

  [A] The floor slab is formed with a column base large opening at the position where the structural column is erected with a hole saw as a drilling jig, and a part of the recess is exposed, and attached to the bottom of the recess for the extension column. The anchor bolt is positioned and a hole 56 for the anchor bolt is formed. A schematic cross-sectional view in this state is shown in FIG. In FIG. 8, 1 is a prefabricated formwork of the present invention, 51 is a main bar arranged in the foundation, 52 is a floor slab constructed by laying a plurality of lightweight cellular concrete floor panels on the top of the foundation. , 53 are openings formed in the floor slab 52.

  [B] As shown in FIG. 3A, the end mold 2 of the assembly mold 1 of the present invention is placed under the floor from the opening 53 with the minimum volume, and the end mold 2 As shown in FIG. 5, the upright plate 11 is placed in contact with the side surface 42 of the recess. Similarly, opposite end formwork is arranged.

  [C] As shown in FIG. 3 (b), the side mold 3 of the assembly mold 1 of the present invention is placed under the floor from the opening 53, and the nail provided on the bottom 33 as shown in FIG. 7 is loosely fitted in the hole 8 in the bottom portion 12 of the end mold 2 previously arranged, and then the side plates 31a and 31b are slid left and right to end the claws 9 formed at one end of the side plates 31a and 31b. The end mold 2 and the side mold 3 are connected to each other by loosely fitting into the holes 10 formed in the upright plate 11 of the partial mold 2 (FIG. 6). Similarly, the other side mold is connected to the end mold, and the assembly mold 1 is assembled, and at the same time, the assembly mold 1 is installed in the recess [FIGS. 7 and 8 (b)]. .

  In addition, this example is a case where the width of the additional concrete is larger than the width of the foundation 40. Therefore, the left and right widths of the upright plate 11 and the bottom plate 12 of the end mold 2 are formed larger than the width of the foundation 40. Has been. In this example, the claw 7 formed on the lower side of the bottom 33 of the side mold 3 is loosely fitted into the hole 8 in the bottom 12 of the end mold 2 and protrudes downward. Since the assembling mold 1 is not lifted from the bottom of the recess, and the claws 7 protrude on both sides so as to sandwich the foundation 40, the assembling mold 1 is in the width direction of the foundation 40. It is possible to prevent slippage and to install it in a predetermined position with certainty. Similarly, the claw 9 loosely fitted in the hole 10 of the upright plate 11 of the end mold 2 protrudes behind the upright plate 11 so as to sandwich the side surface 42 of the recess from both sides. It is possible to prevent the mold frame 1 from being displaced in the width direction of the foundation 40 and reliably install it at a predetermined position.

  [D] An anchor bolt 54 is installed in the hole formed in the previous step, and a band 55 is attached [FIG. 8 (c)]. The anchor bolt may be either an adhesive system or a metal expansion type.

  [E] Place additional concrete in the area surrounded by the assembly form 1.

  FIG. 9 shows the structure after the anchor bolt is added. In the figure, (a) is a schematic plan view, (b) is a schematic cross-sectional view taken along line AA ′ of (a), (c) is a schematic cross-sectional view taken along line BB ′ of (a), and 60 is additional concrete. .

  As shown in FIG. 9, the expanded anchor bolt 54 has a lower end embedded in the existing foundation 40 and an upper end protruding on the expanded concrete 60. Since the concave portion of the foundation 40 is embedded with the additional concrete 60, the column base of the structural column having the same length as the case of standing other than the concave portion can be fixedly installed on the anchor bolt 54.

  According to the present invention, for example, the width of the foundation 40 (= width of the recess) is 140 mm, the height of the recess is 120 to 125 mm, the length of the recess is 320 mm, the width of the additional concrete is 180 mm, and the thickness of the floor slab is In the case of 100 mm, it is possible to add an anchor bolt by providing an opening having a diameter of only 160 mm.

  The present invention is a method and formwork used when a new pillar is erected in the recess of the foundation when remodeling an existing building, but it is also used for repairing a construction failure when a new building is built. Can do.

It is a perspective view of the end part formwork and side formwork of one embodiment of the assembly-type formwork of the present invention. It is the perspective view which combined the edge part formwork and side formwork of FIG. It is the completion figure which assembled the edge part formwork and side formwork of FIG. It is a perspective view which shows the recessed part of the foundation which implements the additional method of the anchor bolt of this invention. It is a perspective view which shows the assembly process of the assembly-type formwork in one Embodiment of the expansion method of the anchor bolt of this invention. It is a perspective view which shows the assembly process of the assembly-type formwork in one Embodiment of the expansion method of the anchor bolt of this invention. It is a perspective view which shows the assembly process of the assembly-type formwork in one Embodiment of the expansion method of the anchor bolt of this invention. It is a cross-sectional schematic diagram which shows the process of one Embodiment of the expansion method of the anchor bolt of this invention. It is a figure which shows the structure which increased the anchor bolt with the expansion method of the anchor bolt of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Assembling formwork 2 End part formwork 3 Side surface formwork 4 Hinge member 5,6 Engagement piece 7,9 Claw 8,10 Hole 11,32 Standing board 11a Frame part 11b Attachment part 12,33 Bottom board 13,14,32a Folded pieces 31a, 31b Side plate 40 Foundation 41 Concave bottom 42 Concave side 51 Main reinforcement 52 Floor slab 53 Opening 54 Anchor bolt 55 Band reinforcement 60 Additional concrete

Claims (7)

An assembly formwork for placing additional concrete in the recess of the concrete foundation under the floor,
It consists of a pair of end molds and a pair of side molds,
The end formwork has an upright plate in contact with the side surface of the recess, and a bottom plate extending in the horizontal direction from the lower end of the upright plate and in contact with the bottom surface of the recess,
The side mold has an upright plate, a bottom plate extending in the horizontal direction from the lower end of the upright plate and in contact with the bottom surface of the recess, and a pair of side plates that overlap the upright plate and slide in the horizontal direction. ,
Standing plate connection that connects the left and right ends of the upright plate of the end formwork and the portions that become the left and right ends of the formwork when the pair of side plates of the side formwork are slid left and right respectively. Part is provided,
An assembly formwork characterized in that bottom plate connecting portions are provided on the left and right ends of the bottom plate of the end mold and the left and right ends of the bottom plate of the side mold, respectively.   The assembly-type formwork of Claim 1 by which the standing board and bottom board of the said edge part formwork are comprised by the hinge part so that folding is possible.   The side frame has an engagement plate that overlaps the upright plate with a predetermined gap above and below the upright plate, and the side plate is slidably fitted in the gap between the upright plate and the engagement plate. The assembly form according to 1 or 2.   The assembly-type formwork in any one of Claims 1-3 in which at least one of the said standing board connection part and a baseplate connection part is comprised with a nail | claw and a hole, and a nail | claw is loosely fitted in a hole.   The assembly-type formwork in any one of Claims 1-4 in which the opening part is formed in the standing board and bottom part of the said end part formwork.   The standing plate of the end mold has a folded piece extending from the left and right ends in a direction perpendicular to the standing plate, and the bottom plate has a folded piece extending vertically upward from the left and right ends. Assembling formwork described in 1. It is a method of adding anchor bolts for erecting a structural column in the recess of a concrete foundation under the floor,
In the floor slab, a column-base opening is formed at the position where the structural column is erected to expose a part of the concave portion of the concrete foundation,
Inserting the end mold and the side mold of the assembly mold according to any one of claims 1 to 5 from the opening, assembling the mold under the floor slab, and installing the mold in the recess,
Attach the anchor bolt to the bottom of the recess from the opening, and fix it.
A method for adding anchor bolts, characterized in that additional concrete is placed in the formwork.

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