Form for forming foundation
The formwork system stabilizes circular formworks using thicker installation members to resist concrete pressure, ensuring structural integrity and simplifying construction processes.
Patent Information
- Application Number
- JP2023210564
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-12-13
- Publication Date
- 2025-06-25
- Estimated Expiration
- 2043-12-13
AI Technical Summary
Circular formworks used in foundation construction are prone to displacement or deformation during concrete placement, necessitating laborious reinforcement and prolonged construction periods.
A formwork system comprising a circular formwork made from a thin plate material with thicker formwork installation members, anchored to an installation surface, to stabilize and prevent displacement.
The system effectively withstands lateral pressure during concrete placement, maintaining the circular formwork's integrity and reducing construction complexity and duration.
Smart Images

Figure 2025094802000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a formwork for foundation formation.
Background Art
[0002] Generally, when constructing foundation concrete, a flat formwork is built and the concrete is placed therein for construction. At that time, the formwork is reinforced with a reinforcing material so as not to be deformed (bulge out) by the lateral pressure of the concrete. Therefore, there have been problems such as laborious construction and a long construction period.
[0003] Therefore, as in Patent Document 1, there is known a method of forming a circular formwork by bending a strip-shaped plate material into a circular shape, placing concrete in the formwork, and constructing foundation concrete. In this method, by using a circular formwork, the concrete lateral pressure can be converted into the circumferential tensile force of the circular formwork, so that the advantage is obtained that a special reinforcement for the formwork is not required while the formwork is constituted by a thin plate material.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, when pouring (placing) concrete, the circular formwork may be displaced or deformed.
[0006] The present disclosure has been made in view of such problems, and an object thereof is to provide a formwork for foundation formation that can withstand the lateral pressure during concrete placement and prevent displacement of the circular formwork.
Means for Solving the Problems
[0007] To solve the above problems, the present invention proposes the following means. One aspect of the present disclosure provides a formwork for foundation formation, comprising: a circular formwork formed on the plate surface of a thin plate material to be curved; and a plurality of formwork installation members attached to the circular formwork for installing the circular formwork on an installation surface, wherein the thickness of each of the plurality of formwork installation members is greater than the thickness of the plate material.
Advantages of the Invention
[0008] The present disclosure can provide a formwork for foundation formation that can withstand the lateral pressure during concrete placement and prevent displacement of the circular formwork.
Brief Description of the Drawings
[0009]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Embodiments for Carrying Out the Invention
[0010] Hereinafter, an embodiment of the formwork 1 for foundation formation according to the present disclosure will be described with reference to the drawings. FIG. 1 shows a perspective view of the formwork 1 for foundation formation in this embodiment.
[0011] The formwork 1 for foundation formation is used for forming foundation concrete. As shown in FIG. 1, reinforcing bars 110 and anchor bolts 120 are arranged inside the formwork 1 for foundation formation. Note that upper end bars (not shown) may be provided above the reinforcing bars 110.
[0012] In this embodiment, four anchor bolts 120 are symmetrically provided about the central axis O1 of the circular formwork 10. The arrangement and number of the anchor bolts 120 are not particularly limited.
[0013] The arrangement and configuration of the reinforcing bars 110 are not particularly limited. The arrangement and configuration of the reinforcing bars 110 can be appropriately set according to, for example, the size of the foundation concrete.
[0014] FIG. 2 shows the formwork 1 for forming a foundation installed on the installation surface 140. As shown in FIG. 2, the circular formwork 10 is installed on the installation surface 140 of the excavation part 130 of the ground G1. The circular formwork 10 is fixed by the formwork installation member 20. A discarded concrete layer may be formed on the installation surface 140. By placing the concrete C into the formwork 1 for forming a foundation installed in this way, the foundation concrete is constructed.
[0015] FIG. 3 shows the formwork 1 for forming a foundation in a plan view. As shown in FIG. 3, the formwork 1 for forming a foundation has a circular formwork 10 and a formwork installation member 20.
[0016] The circular formwork 10 is configured by bending the plate material 11 and connecting it at the connection part 12. The connection part 12 is provided at both ends of the plate material 11. Specifically, the circular formwork 10 is formed by overlapping the connection parts 12 of the plate materials 11 and fixing them with the fixing parts 13 (bolts in this embodiment). The connection method (fixing part 13) of the plate materials 11 is not limited to bolts. For example, the connection parts 12 of the plate materials 11 to be connected may be overlapped and fixed by welding (for example, spot welding, etc.). In this embodiment, five fixing parts 13 are provided per one connection part 12 (see FIG. 1 etc.). The number of fixing parts 13 per one connection part 12 is not limited.
[0017] In this embodiment, three plate materials 11 are connected. The number of the plate materials 11 is not limited to three, and may be one, or two or four or more.
[0018] The plate material 11 is strip-shaped. The longitudinal length of the plate material 11 is the circumferential length of the circular formwork 10. Hereinafter, the longitudinal length of the plate material 11 is taken as the circumferential length. In the present embodiment, only one of the plurality of plate materials 11 has a different circumferential length, and the circumferential lengths of the other plate materials 11 are the same. Specifically, the circular formwork 10 in the present embodiment is composed of plate materials 11 with two types of circumferential lengths, and there are two plate materials 11a (with a long circumferential length) and one plate material 11b (with a short circumferential length). However, the combination of the number of the plate materials 11a and the plate materials 11b is not limited to this.
[0019] The combination with the circumferential length of the plate material 11 used for the circular formwork 10 is not limited to the above. The circumferential lengths of the plate materials 11 used for the circular formwork 10 may all be the same, or may all be different. For example, a plurality of types of plate materials 11 with different circumferential lengths may be prepared in advance, and by changing the number and types of the combined plate materials 11, a circular formwork 10 may be formed according to the size of the foundation concrete to be constructed.
[0020] The plate material 11 in the present embodiment is a steel plate. The material of the plate material 11 is not limited to the steel plate.
[0021] FIG. 4 shows a view taken in the direction of arrow A in FIG. 3. The short-side length of the plate material 11 (the height of the circular formwork 10) is not limited. The thickness T2 of the plate material 11 may be thinner than the thickness T1 of the formwork installation member 20, and the specific thickness is not limited (see FIG. 5).
[0022] The formwork installation member 20 is used for fixing the circular formwork 10. As shown in FIG. 3, it is preferable that the installation surface side fixing portion 22 of the formwork installation member 20 to be described later extends in the radius r direction of the circle formed by the circular formwork 10 in plan view. In this embodiment, the circular formwork 10 is fixed by four formwork installation members 20 arranged at equal intervals. The number of formwork installation members 20 used for fixing the circular formwork 10 is not limited to four, and may be one, two, three, or five or more. When the number of formwork installation members 20 used for fixing the circular formwork 10 is plural, it is preferable that the formwork installation members 20 are arranged at intervals in the circumferential direction. At this time, the formwork installation members 20 may be arranged at unequal intervals or at equal intervals.
[0023] FIG. 5 shows an enlarged view of the formwork installation member 20 connected to the circular formwork 10 and the installation surface 140. As shown in FIG. 5, the formwork installation member 20 in this embodiment is an L-shaped metal fitting. Note that the shape and material of the formwork installation member 20 are not limited. When the formwork installation member 20 is connected to the circular formwork 10 and the installation surface 140, the side in contact with the circular formwork 10 is defined as the formwork side fixing portion 21, and the side in contact with the installation surface 140 is defined as the installation surface side fixing portion 22. Note that the formwork side fixing portion 21 and the installation surface side fixing portion 22 extend in a substantially perpendicular direction. Here, substantially perpendicular means not only when the angle α between the formwork side fixing portion 21 and the installation surface side fixing portion 22 in the side view of the formwork installation member 20 is 90 degrees, but also, for example, the angle α may differ by 10 degrees from 90 degrees, or the angle α may be 80 degrees or more and 100 degrees or less. The ratio of the length L1 in the extending direction of the formwork side fixing portion 21 to the length L2 in the extending direction of the installation surface side fixing portion 22 may be in the range of 1:1.5 to 1:2.0. The length L1 may be shorter than the length L2, and 1.5 ≦ (L2 / L1) ≦ 2.0 may be satisfied. In this embodiment, the formwork side fixing portion 21 is integrally attached to the outside of the circular formwork 10, and the installation surface side fixing portion 22 extends outward from the circular formwork 10. Note that the formwork side fixing portion 21 may be integrally attached to the inside of the circular formwork 10, and the installation surface side fixing portion 22 may extend inward from the circular formwork 10. Here, integrally attached means that the circular formwork 10 and the formwork side fixing portion 21 are in surface contact and fixed.
[0024] In this embodiment, the mounting surface side fixing portion 22 is fixed to the mounting surface 140 at two locations, and the formwork side fixing portion 21 is fixed to the circular formwork 10 at one location. The mounting surface side fixing portion 22 may be fixed to the mounting portion at one location or at a plurality of locations. The formwork side fixing portion 21 may be fixed to the circular formwork 10 at one location or at a plurality of locations.
[0025] For example, the mounting surface side fixing portion 22 may be fixed to the mounting surface 140 at one location, and the formwork side fixing portion 21 may be fixed to the circular formwork 10 at two or more locations. The mounting surface side fixing portion 22 may be fixed to the mounting surface 140 at one location, and the formwork side fixing portion 21 may be fixed to the circular formwork 10 at one location. The mounting surface side fixing portion 22 may be fixed to the mounting surface 140 at two or more locations, and the formwork side fixing portion 21 may be fixed to the circular formwork 10 at two or more locations.
[0026] The fixing method of the formwork mounting member 20 is not limited. In this embodiment, the mounting surface side fixing portion 22 is fixed to the mounting surface 140 with nails (concrete nails), and the formwork side fixing portion 21 is fixed to the circular formwork 10 with bolts. The formwork side fixing portion 21 may be fixed to the circular formwork 10 by spot welding. When using nails or bolts for fixing, the number of nails or bolts used can be the same as the number of fixing locations. When using spot welding for fixing, the number of spot welds can be the same as the number of fixing locations.
[0027] The width of the formwork mounting member 20 is not limited. The thickness T1 of the formwork mounting member 20 may be thicker than the thickness T2 of the plate material 11, and the specific thickness is not limited. The thickness T1 of the formwork mounting member 20 is preferably, for example, the thickness for making the circular formwork 10 stand on its own. The thickness T1 of the formwork mounting member 20 is preferably, for example, the thickness for stabilizing the shape of the circular formwork 10. When there are a plurality of formwork mounting members 20 used for fixing the circular formwork 10, the thicknesses T1 of the plurality of formwork mounting members 20 are preferably the same. However, the thicknesses T1 of the plurality of formwork mounting members 20 may be different.
[0028] The thickness of the formwork mounting member 20 is preferably 3 times or more the thickness of the plate material 11. If the thickness of the formwork mounting member 20 is 3 times or more the thickness of the plate material 11, the circular formwork 10 can be made to stand on its own and its shape can be stabilized. From the viewpoints of the weight and cost of the formwork mounting member 20, the thickness T1 of the formwork mounting member 20 is preferably 8 times or less the thickness T2 of the plate material 11.
[0029] By placing the concrete C in the foundation forming formwork 1 described above, the foundation concrete is constructed. At this time, the circular formwork 10 is formed in a circular shape in plan view by receiving, from the concrete C to be placed, a uniform force around the circular formwork 10 according to the height.
[0030] As described above, the foundation forming formwork 1 according to the present embodiment includes a circular formwork 10 formed on the plate surface of a thin plate material 11 that is curved, and a plurality of formwork mounting members 20 that are attached to the circular formwork 10 and attach the circular formwork 10 to the installation surface 140. The thickness T1 of each of the plurality of formwork mounting members 20 is thicker than the thickness T2 of the plate material 11. By using such a formwork mounting member 20, the circular formwork 10 made of the thin plate material 11 can be made to stand on its own, withstand the lateral pressure during concrete C placement, and prevent displacement of the circular formwork 10.
[0031] Also, the thicknesses T1 of the plurality of formwork mounting members 20 may be the same. If the thicknesses T1 of the plurality of formwork mounting members 20 are the same, when the concrete C is placed inside the foundation forming formwork 1, the lateral pressure of the concrete C can be evenly dispersed. Therefore, it can withstand the lateral pressure during concrete C placement and prevent displacement of the circular formwork 10.
[0032] Also, the circular formwork 10 may be formed in a circular shape in plan view by receiving, from the concrete C to be placed, a uniform force around the circular formwork 10 according to the height. As a result, even if the plate material 11 constituting the circular formwork 10 is thin, the circular formwork 10 can maintain a true circular shape by receiving uniform force around the circular formwork 10. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the circular formwork 10.
[0033] The plurality of formwork installation members 20 include a formwork side fixing portion 21 fixed to the circular formwork 10 and a mounting surface side fixing portion 22 fixed to the mounting surface 140, and the formwork side fixing portion 21 and the mounting surface side fixing portion 22 may extend in a direction substantially perpendicular to each other. As a result, the plate material 11 of the circular formwork 10 can be installed substantially perpendicular to the mounting surface 140. Therefore, the lateral pressure during the placement of the concrete C can be evenly dispersed to the plate material 11, and it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the circular formwork 10.
[0034] Further, the formwork side fixing portion 21 may be attached to the outside of the circular formwork 10. Further, the mounting surface side fixing portion 22 may extend outward from the circular formwork 10. As a result, when the concrete C is placed, it is preferable because the formwork installation member 20 does not interfere with the foundation concrete.
[0035] Further, the mounting surface side fixing portion 22 may extend in the radial direction r of the circle formed by the circular formwork 10 in a plan view. When the concrete C is placed in the circular formwork 10, lateral pressure is applied in the direction from the central axis O1 toward the side surface. For this reason, by installing the mounting surface side fixing portion 22 to extend in the radial direction r of the circle formed by the circular formwork 10 in a plan view, it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the circular formwork 10.
[0036] The mounting surface side fixing portion 22 may be fixed to the mounting surface 140 at two or more locations, and the formwork side fixing portion 21 may be fixed to the circular formwork 10 at one location. As a result, since the installation surface side fixing portion 22 is fixed at two or more points, it is possible to prevent lateral displacement when a load is applied to the installation surface side fixing portion 22. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the circular formwork 10 from shifting.
[0037] The installation surface side fixing portion 22 may be fixed at one or more locations on the installation surface 140, and the formwork side fixing portion 21 may be fixed at two locations on the circular formwork 10. As a result, since the formwork side fixing portion 21 is fixed at two or more points, it is possible to prevent lateral displacement when a load is applied to the formwork side fixing portion 21. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the circular formwork 10 from shifting.
[0038] The installation surface side fixing portion 22 may be fixed at one location on the installation surface 140, and the formwork side fixing portion 21 may be fixed at one location on the circular formwork 10. As a result, the cost can be reduced, the work of fixing the installation surface side fixing portion 22 can be simplified, and the construction can be facilitated.
[0039] The installation surface side fixing portion 22 may be fixed at two or more locations on the installation surface 140, and the formwork side fixing portion 21 may be fixed at two or more locations on the circular formwork 10. As a result, since both the installation surface side fixing portion 22 and the formwork side fixing portion 21 are fixed at two or more points, the circular formwork 10 can be firmly fixed. Therefore, it can withstand the lateral pressure during the placement of the concrete C and more reliably prevent the circular formwork 10 from shifting.
[0040] The circular formwork 10 is formed of a plurality of plate materials 11, and the plurality of plate materials 11 may include those having different circumferential lengths of the circular formwork 10. As a result, by combining the plate materials 11 having different circumferential lengths, circular formworks 10 with various circumferential lengths can be formed. Therefore, it is not necessary to create the plate materials 11 according to the size of the foundation concrete to be constructed, the cost can be reduced, and it can be used as the formwork 1 for foundation formation that is easy to construct. Here, when the plurality of plate members 11 include those with different circumferential lengths of the circular formwork 10, the plurality of plate members 11 are composed of a first plate member 11 having a first length in the circumferential direction of the circular formwork 10 and a second plate member 11 having a second length in the circumferential direction of the circular formwork 10, and the first plate member 11 and the second plate member 11 may each be composed of the same number (one or more).
[0041] Only one of the plurality of plate members 11 may have a different circumferential length, and the lengths of the other plate members 11 in the circumferential direction may be the same. Thereby, by combining plate members 11 with different circumferential lengths, circular formworks 10 with various circumferential lengths can be formed, and the types of plate members 11 used can be limited to two. Therefore, the cost can be reduced, and the formwork 1 for foundation formation that is easy to construct can be obtained.
[0042] All of the plurality of plate members 11 may have different circumferential lengths of the circular formwork 10. Thereby, by combining plate members 11 with different circumferential lengths, circular formworks 10 with various circumferential lengths can be formed.
[0043] Formed by a plurality of plate members 11, all of the plurality of plate members 11 may have the same circumferential length of the circular formwork 10. Thereby, the types of plate members 11 used can be limited to one. Therefore, the cost can be reduced, and the formwork 1 for foundation formation that is easy to construct can be obtained.
[0044] The plurality of formwork installation members 20 may be arranged at intervals from each other in the circumferential direction. Thereby, in order to disperse the lateral pressure received from the concrete C to the plurality of formwork installation members 20, the formwork installation members 20 can be arranged at appropriate positions. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the formwork 1 for foundation formation from shifting in position.
[0045] The plurality of formwork installation members 20 may be arranged at unequal intervals. As a result, even if the circumferential lengths of the plurality of plate members 11 are different, the formwork installation member 20 can be arranged at an appropriate position according to the circumferential length of the plate member 11.
[0046] The plurality of formwork installation members 20 may be arranged at equal intervals. As a result, the lateral pressure received from the concrete C can be evenly distributed to the plurality of formwork installation members 20. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the formwork 1 for foundation formation.
[0047] The thickness T1 of the formwork installation member 20 is 8 times or less the thickness T2 of the plate member 11. As a result, it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the formwork 1 for foundation formation, and the cost and weight of the formwork installation member 20 can be reduced.
[0048] The ratio of the length L1 in the extending direction of the formwork side fixing portion 21 to the length L2 in the extending direction of the installation surface side fixing portion 22 may be in the range of 1:1.5 to 1:2.0. The length L2 in the extending direction of the installation surface side fixing portion 22 is longer than the length L1 in the extending direction of the formwork side fixing portion 21. As a result, the lateral pressure received from the concrete C can be transmitted to the installation surface 140 through the installation surface side fixing portion 22 with a long length L2. Therefore, it is possible to prevent the circular formwork 10 composed of thin plate members from falling. Therefore, it can withstand the lateral pressure during the placement of the concrete C and prevent the displacement of the formwork 1 for foundation formation. Further, by suppressing the length L2 in the extending direction of the installation surface side fixing portion 22 to a certain extent (the length L1 of the formwork side fixing portion 21: the length L2 of the installation surface side fixing portion 22 = 1:1.5 to 1:2.0), it is possible to prevent the formwork installation member 20 from becoming large-sized.
[0049] As described above, one embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and includes configuration changes, combinations, deletions, etc. within the scope not departing from the gist of the present disclosure.
Explanation of Reference Numerals
[0050] 1 Formwork for base formation 10 Circular formwork 11, 11a, 11b Plate materials 12 Connection part 13 Fixing part 20 Formwork installation member 21 Formwork side fixing part 22 Installation surface side fixing part 140 Installation surface G1 Ground O1 Central axis C Concrete L1 Length in the extending direction of the formwork side fixing part L2 Length in the extending direction of the installation surface side fixing part T1 Thickness of the formwork installation member T2 Thickness of the plate material
Claims
1. a circular formwork formed on the surface of a thin plate material that is bent, and a plurality of formwork installation members attached to the circular formwork for installing the circular formwork on a mounting surface, The thickness of each of the plurality of formwork installation members is thicker than the thickness of the plate material, a formwork for foundation formation.
2. The thickness of the formwork installation member is of a size that enables the circular formwork to stand independently, the formwork for foundation formation according to Claim 1.
3. The thickness of the formwork installation member is of a size that stabilizes the shape of the circular formwork, the formwork for foundation formation according to Claim 1.
4. The thicknesses of the plurality of formwork installation members are the same, the formwork for foundation formation according to Claim 1.
5. The circular formwork is formed in a circular shape in plan view by receiving, from the cast concrete, a uniform force around the circular formwork according to the height, the formwork for foundation formation according to Claim 1.
6. The plurality of formwork installation members include a formwork-side fixing portion fixed to the circular formwork and a mounting-surface-side fixing portion fixed to the mounting surface, The formwork-side fixing portion and the mounting-surface-side fixing portion extend in a substantially perpendicular direction, the formwork for foundation formation according to Claim 1.
7. The formwork-side fixing portion is attached to the outside of the circular formwork, the formwork for foundation formation according to Claim 6.
8. The mounting-surface-side fixing portion extends outward from the circular formwork, the formwork for foundation formation according to Claim 6.
9. The mounting-surface-side fixing portion extends in the radial direction of the circle formed by the circular formwork in plan view, the formwork for foundation formation according to Claim 6.
10. The mounting-surface-side fixing portion is fixed to the mounting surface at two or more locations, The formwork-side fixing portion is fixed to the circular formwork at one location, the formwork for foundation formation according to Claim 7.
11. The mounting-surface-side fixing portion is fixed to the mounting surface at one location, The formwork-side fixing portion is fixed to the circular formwork at two or more locations, the formwork for foundation formation according to Claim 7.
12. The mounting-surface-side fixing portion is fixed to the mounting surface at one location, The formwork-side fixing portion is fixed to the circular formwork at one location, the formwork for foundation formation according to Claim 7.
13. The mounting-surface-side fixing portion is fixed to the mounting surface at two or more locations, The formwork-side fixing portion is fixed to the circular formwork at two or more locations, the formwork for foundation formation according to Claim 7.
14. The circular formwork is formed of a plurality of plate materials, The formwork for foundation formation according to claim 7, wherein the plurality of plate materials include those having different circumferential lengths of the circular formwork.
15. The formwork for foundation formation according to claim 14, wherein only one of the plurality of plate materials has a different circumferential length, and the circumferential lengths of the other plate materials are the same.
16. The formwork for foundation formation according to claim 14, wherein all of the plurality of plate materials have different circumferential lengths of the circular formwork.
17. The circular formwork is formed of a plurality of plate materials. The formwork for foundation formation according to claim 7, wherein all of the plurality of plate materials have the same circumferential length of the circular formwork.
18. The formwork for foundation formation according to any one of claims 1 to 17, wherein the plurality of formwork installation members are arranged at intervals in the circumferential direction.
19. The formwork for foundation formation according to claim 18, wherein the plurality of formwork installation members are arranged at unequal intervals.
20. The formwork for foundation formation according to claim 18, wherein the plurality of formwork installation members are arranged at equal intervals.
21. The formwork for foundation formation according to any one of claims 1 to 17, wherein the thickness of the formwork installation member is 8 times or less the thickness of the plate material.
22. The formwork for foundation formation according to claim 6, wherein the ratio of the length in the extending direction of the formwork side fixing portion to the length in the extending direction of the installation surface side fixing portion is in the range of 1:1.5 to 1:2.0.
Citation Information
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