Foundation structure by 3D printed embedded formwork, and manufacturing method of foundation

Abstract

To provide a foundation structure by a 3D printed embedded formwork and a manufacturing method of a foundation which utilize 3D printer technology to increase peripheral friction of a foundation structure and effectively improve the support performance of the foundation structure.SOLUTION: A foundation structure 100 by a 3D printed embedded formwork includes at least: a 3D printed embedded formwork 10 formed by a layered type 3D printer; and filled concrete 20 filled in an area partitioned by the 3D printed embedded formwork 10. The 3D printed embedded formwork 10 has a partition wall 11 made of a plurality of laminated material layers 12 stacked upward. The laminated material layers 12 form an uneven shape and an aspect ratio of the uneven shape is adjusted.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a foundation structure and a method for manufacturing a foundation using a 3D printed buried formwork, in which a buried formwork formed by a 3D printer is applied to a foundation structure. [Background technology]

[0002] Conventionally, for example, Patent Document 1 discloses a technique for efficiently constructing a structure by forming a footing partition wall using a 3D printer and filling the interior of the partition wall with concrete.

[0003] Furthermore, Patent Document 2 describes the creation of a layered structure using a 3D printer that dispenses mortar, and using the layered structure as a formwork that is filled with concrete to build walls and pillars.

[0004] In recent years, the use of 3D printers as described above has become more widespread, and various studies are being conducted on their automation and labor-saving technologies. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication 2018-199939 [Patent Document 2] Patent Publication No. 2022-174879 Summary of the Invention [Problem to be solved by the invention]

[0006] However, for foundation structures, especially columnar foundations and pile foundations, the calculation of bearing capacity and the upper limit values ​​of the subgrade reaction coefficient and subgrade reaction degree used in the design can only be based on the standard values, and the foundation cannot be made smaller. As a result, in places where other buried objects or important structures are nearby, it may not be possible to obtain a viable proposal for the foundation structure.

[0007] In view of the above-mentioned problems, the present invention aims to provide a method for manufacturing a foundation structure and a foundation using a 3D printed buried formwork, which utilizes the above-mentioned 3D printer technology to increase the peripheral friction of the foundation structure and effectively improve the support performance of the foundation structure. [Means for solving the problem]

[0008] The invention related to (1) is a foundation structure using a 3D printed embedded formwork having at least a 3D printed embedded formwork formed by an additive type 3D printer and filled concrete filled into an area partitioned by the 3D printed embedded formwork, wherein the 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked upward, the laminated material layers form an uneven shape, and the aspect ratio of the uneven shape is adjusted.

[0009] The invention related to (2) is a foundation structure using the 3D printed embedded formwork described in (1) above, in which the aspect ratio (H / V) of the uneven shape is 0.13 to 0.44.

[0010] The invention related to (3) is a foundation structure using a 3D printed embedded formwork having at least a 3D printed embedded formwork formed by an additive type 3D printer and filled concrete filled in an area partitioned by the 3D printed embedded formwork, wherein the 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked upward, and the outer end of the laminated material layer has a protrusion that protrudes outward from the partition wall further than the outer end of the adjacent laminated material layer above and / or below.

[0011] The invention related to (4) is a foundation structure using a 3D printed embedded formwork having at least a 3D printed embedded formwork formed by an additive type 3D printer and filled concrete filled in an area partitioned by the 3D printed embedded formwork, wherein the 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked upward, and the inner end of the laminated material layer has a protrusion that protrudes toward the inside of the partition wall more than the inner end of the adjacent laminated material layer above and / or below.

[0012] The invention related to (5) is a foundation structure using a 3D printed embedded formwork described in (3) or (4) above, in which the protrusions are formed at multiple locations at predetermined intervals in the horizontal cross section of the partition wall.

[0013] The inventions related to (6) and (7) are foundation structures using a 3D printed buried formwork described in any one of (1) to (5) above, wherein the foundation structure is a columnar foundation or a pile foundation.

[0014] The invention related to (8) is a method for manufacturing a foundation using a 3D printed embedded form having at least a 3D printed embedded form formed by an additive 3D printer and filled concrete filled into the area partitioned by the 3D printed embedded form, the method including at least the steps of manufacturing a 3D printed embedded form by stacking a plurality of laminated material layers upward to form a partition wall, and filling the area partitioned by the 3D printed embedded form with filled concrete, wherein in the step of manufacturing the 3D printed embedded form, the laminated material layers are stacked in an uneven shape and the aspect ratio of the uneven shape is adjusted. Effect of the Invention

[0015] According to the inventions related to (1), (2), and (8) above, by forming an uneven shape in the laminated material layer of the 3D printed embedded formwork and adjusting the aspect ratio of the uneven shape, it is possible to increase the peripheral friction of the foundation and improve its support performance compared to a conventional structure in which the aspect ratio of the uneven shape was not adjusted. In particular, by setting the aspect ratio (H / V) of the uneven shape to 0.13 to 0.44, it is possible to increase the tangent of the friction angle (tanφ) to about 1.49 times compared to a concrete plate with a smooth surface, and it is possible to increase the peripheral friction of the foundation and improve its support performance.

[0016] More specifically, the surface friction force used to calculate the bearing capacity and the shear resistance of the ground (for example, the horizontal shear subgrade reaction coefficient of the side of the foundation and the upper limit of that subgrade reaction force, and the vertical shear subgrade reaction coefficient of the surface of the foundation and the upper limit of that subgrade reaction force) can be made larger than before, making it possible to reduce the cross-sectional dimensions of the foundation and shorten the foundation in the depth direction compared to before.

[0017] According to the inventions relating to (3) and (4) above, by making the outer end or inner end of the laminated material layer in the 3D printed buried formwork protrude beyond the outer end or inner end of the adjacent laminated material layer above and / or below, it is possible to increase the peripheral friction of the foundation and improve its supporting performance.

[0018] According to the invention relating to (5) above, the protrusions formed by the laminated material layer in the 3D printed buried formwork are formed at multiple locations at predetermined intervals in the horizontal cross section of the 3D printed buried formwork, making it possible to adjust (set) the peripheral friction and support performance while increasing the peripheral friction of the foundation.

[0019] According to the inventions related to (6) and (7) above, when the cross-sectional configuration of the above-mentioned 3D printed buried formwork is applied to a columnar foundation or a pile foundation, it is possible to increase the peripheral friction and improve the support performance. In addition, for example, when buried objects or important structures are located nearby, it is possible to make the foundation smaller (shorter) and satisfy the construction conditions. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a perspective view of a pillar base in the first embodiment of the present invention. [Diagram 2] 1A is a top plan view of part a in FIG. 1, and FIG. [Diagram 3] FIG. 2(a) is a cross-sectional view taken along line AA of FIG. 2(a) in a second embodiment of the present invention, and FIG. 2(b) is a cross-sectional view taken along line AA of FIG. 2(a) in a third embodiment of the present invention. [Figure 4] FIG. 2(a) is a cross-sectional view taken along line AA in FIG. [Diagram 5] 10A is a plan cross-sectional view of a 3D printed buried formwork in a fourth embodiment of the present invention, and FIG. 10B is a cross-sectional view taken along lines AA and BB in FIG. [Figure 6] FIG. 1 is a cross-sectional view illustrating a friction test using a single shear tester. [Figure 7] 1 is a graph comparing the relationship between vertical stress and maximum shear stress obtained in a friction test on clay soil between the 3D printed embedded formwork of this embodiment and a concrete slab. [Figure 8] 1 is a table showing the results of friction tests on each soil type. [Figure 9] This is a table showing the aspect ratio (H / V) of the uneven shape of the 3D printed embedded formwork used in the friction test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, with reference to the drawings, various embodiments of the foundation structure using the 3D printed buried formwork of the present invention will be described.

[0022] FIG. 1 shows a perspective view of a foundation structure 100 for a columnar body foundation as a first embodiment of the present invention. The foundation structure 100 has a 3D printed embedded formwork 10 formed by a layered 3D printer on the outer shell of the columnar body foundation, and is configured to include at least filled concrete 20 that is filled into the area partitioned by the 3D printed embedded formwork 10.

[0023] Fig. 2(a) shows a top plan view of part a in Fig. 1, and Fig. 2(b) shows a cross-sectional view along the line AA in Fig. 2(a). In this embodiment, for example, premix mortar for 3D printers is stacked vertically as shown in Fig. 2(b) to form the partition wall 11 of the 3D print embedded formwork 10.

[0024] In this embodiment, a premixed mortar for 3D printers is used, and the premixed mortar for 3D printers is a laminated material made by mixing Portland cement, fine aggregate, hardening accelerator, thixotropy regulator, and organic fiber, but this laminated material is merely an example and can be changed as appropriate. Then, a plurality of laminated material layers 12 are laminated upward to form a partition wall 11. In this embodiment, the interval between the layers is about 5 mm, and the height of the formed unevenness is about 1 mm.

[0025] When stacking the laminated material layers 12, as shown in Figure 2 (b), the outer end portion 121 of each laminated material layer 12 forms an uneven shape, and the laminated material layers are adjusted to form an uneven shape with an aspect ratio (H / V) in the range of 0.13 to 0.44.

[0026] More specifically, Fig. 9 shows the vertical dimension, i.e., the width (V) of the convex portion, the horizontal dimension, i.e., the height (H) of the convex portion, and the aspect ratio (H / V) calculated from these dimensions of the concaves and convexes formed by each laminated material layer 12 in the 3D printed buried formwork 10 formed as described above. Fig. 7 shows a graph comparing the relationship between the vertical stress and the maximum shear stress obtained in a friction test on clay soil between the 3D printed buried formwork and a concrete plate.

[0027] As is clear from the results of the friction tests shown in Figure 7, by forming an uneven shape with an aspect ratio (H / V) in the above-mentioned range of 0.13 to 0.44, it is possible to increase the tangent of the friction angle (tanφ) by approximately 1.49 times compared to a concrete plate with a smooth surface.

[0028] This improved frictional resistance can increase the surface friction and improve the bearing capacity, especially in columnar and pile foundations. Therefore, for example, when buried objects or important structures are located nearby, it becomes possible to make the foundation smaller (shorter).

[0029] Next, FIG. 3(a) shows a cross-sectional view taken along line AA of FIG. 2(a) in a second embodiment of the present invention, and FIG. 3(b) shows a cross-sectional view taken along line AA of FIG. 2(a) in a third embodiment of the present invention.

[0030] That is, in the second embodiment of Fig. 3(a) and the third embodiment of Fig. 3(b), the outer end 121 of the laminated material layer 12 is configured to have a protruding portion 111 that protrudes further outward from the partition wall 11 than the outer end portions 121 of the laminated material layers 12 adjacent above and below. This makes it possible to increase the peripheral friction of the foundation and improve its supporting performance.

[0031] 2(a) in a fourth embodiment of the present invention, in which the outer end 121 of the laminated material layer 12 is configured to have a protruding portion 111 that protrudes outward from the partition wall 11 beyond the outer end 121 of the adjacent laminated material layer 12 above or below. This makes it possible to increase the peripheral friction of the foundation and improve its support performance.

[0032] Next, FIG. 5(a) shows a plan cross-sectional view of a 3D printing embedded formwork 10 in a fifth embodiment of the present invention, and FIG. 5(b) shows a cross-sectional view along the line AA and a cross-sectional view along the line BB in FIG. 5(a).

[0033] That is, in the fifth embodiment, as shown in the horizontal cross-sectional view of Fig. 5(a), the protrusions 111 are configured to be provided at a plurality of locations at predetermined intervals in the horizontal cross section of the partition wall 11 of the 3D print embedded formwork 10. This makes it possible to adjust (set) the peripheral friction and support performance while increasing the peripheral friction of the foundation.

[0034] The second to fifth embodiments of the present invention have been described above. However, it is also possible to apply the cross-sectional configurations of the second, third, and fourth embodiments to the AA cross section of the fifth embodiment in FIG. 5(b).

[0035] In addition, in the above-mentioned second to fifth embodiments, an example was shown in which a protrusion 111 is provided on the outside of the 3D printed buried formwork 10, but it is also possible to provide the protrusion 111 on the inside of the 3D printed buried formwork 10, which also makes it possible to increase the peripheral friction of the foundation and improve its supporting performance.

[0036] In addition, the inclination angle of each laminate layer 12 formed in the protruding portion 111 is preferably 45° or more as shown in the figure, in order to ensure that the uncured laminate is stable and self-supporting. However, it is also possible to form the protruding portion 111 at an inclination angle of 45° or less by using a separate support structure or the like.

[0037] (Verification results from friction tests) A friction test was performed on the 3D-printed embedded form of the present invention using a single-side shear tester as shown in Fig. 6. That is, a standard single-side shear tester was used, and a concrete plate with a smooth surface and the 3D-printed embedded form were fixed in place of the lower shear box, and friction tests were performed on each of them.

[0038] In the example shown in Figure 6, the upper half of the shear box was placed on top of the 3D printed buried formwork, and a clayey soil sample with a diameter of 60 mm and a thickness of 1 cm was placed inside, confining pressure was applied, and the sample was left to rest for about two days until consolidation was complete. Note that in this verification test, Kasaoka clay was used as the clayey soil, and the water content was adjusted to 60% to simulate a soft alluvial clay layer.

[0039] During the test, the 3D printed embedded formwork was moved horizontally, and six tests were conducted with different confining pressures (six types: 10, 20, 40, 50, 100, and 200 kPa).The friction angle φ was calculated using the least squares method from the relationship between the obtained vertical stress σ and maximum shear stress τ.

[0040] The method for determining the above confining pressure is the coefficient of earth pressure at rest K h = 0.5 and the wet unit volume weight of soil γ t =19kN / m 3 Using σ'=K h Gamma t Using the formula, the horizontal resting earth pressure at 20m underground was assumed to be 50, 100, and 200kPa. Then, a test was conducted under these confining pressures to obtain the friction angle φ and adhesion c.

[0041] As a result of the above-mentioned test, as is clear from the result of the friction test shown in Fig. 7, the 3D printed buried formwork having an uneven shape with an aspect ratio (H / V) in the range of 0.13 to 0.44 described above can increase the tangent of the friction angle (tanφ) by about 1.49 times compared to a concrete plate with a smooth surface. Naturally, the 3D printed buried formwork of the second to fifth embodiments having a larger protrusion 111 than the 3D printed buried formwork having an uneven shape with an aspect ratio (H / V) in the range of 0.13 to 0.44 can obtain an even larger peripheral friction force.

[0042] Furthermore, the results of friction tests on dry fine sand, saturated fine sand, dry coarse sand, and saturated coarse sand other than clayey soil are shown in Figure 8. In all cases, the friction angle tanφ is increased by 1.12 to 1.28 times compared to the concrete plate, and it is possible to increase the peripheral friction of the foundation and improve its bearing capacity in all soil types.

[0043] The above describes each embodiment of the present invention and the results of the verification experiment. According to the present invention, the characteristic uneven shape formed on the 3D printed buried formwork 10 can effectively increase the peripheral friction with the ground. This allows the peripheral friction force used in calculating the bearing capacity and the shear resistance of the ground (for example, the horizontal shear subgrade reaction coefficient of the foundation side and the upper limit of that subgrade reaction coefficient, the vertical shear subgrade reaction coefficient of the foundation peripheral surface and the upper limit of that subgrade reaction coefficient) to be larger than before. As a result, it becomes possible to reduce the cross-sectional dimensions of the foundation and reduce the amount of reinforcing bars in the foundation compared to before. Furthermore, it becomes possible to shorten the foundation in the depth direction.

[0044] In addition, in each of the above-described embodiments, the spacing between the layers of the laminated material layer 12 is about 5 mm, and the height of the unevenness formed is about 1 mm, but the dimensions are not necessarily limited to these, and for example, the spacing between the layers can be about 10 mm. By increasing the spacing (thickness) between the layers in this way, the height of the unevenness also increases, which makes it possible to further increase the peripheral friction of the foundation.

[0045] The scope of the present invention is indicated by the claims, not by the description of each embodiment above, and includes all modifications within the meaning and scope of the claims. In addition, the specific materials, dimensions, shapes, etc. described in the above embodiments can be modified within the scope of the present invention. [Explanation of symbols]

[0046] 10 3D printed buried formwork 11 Bulkhead 111 Protrusion 12 Laminated material layer 121 Outer edge 122 Inner end 20. Filled Concrete 100 Basic structure

Claims

1. A foundation structure using a 3D printed embedded form having at least a 3D printed embedded form formed by a layered 3D printer and filled concrete filled in an area partitioned by the 3D printed embedded form, The 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked on top of each other, The laminated material layer forms a concave-convex shape, and the aspect ratio of the concave-convex shape is adjusted. A foundation structure made using 3D printed embedded formwork.

2. The aspect ratio (H / V) of the uneven shape is 0.13 to 0.

44. A foundation structure formed by the 3D printed buried formwork described in claim 1.

3. A foundation structure using a 3D printed embedded form having at least a 3D printed embedded form formed by a layered 3D printer and filled concrete filled in an area partitioned by the 3D printed embedded form, The 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked on top of each other, The outer end of the laminate layer has a protruding portion that protrudes outward from the partition wall beyond the outer end of the laminate layer adjacent thereto above and / or below. A foundation structure made using 3D printed embedded formwork.

4. A foundation structure using a 3D printed embedded form having at least a 3D printed embedded form formed by a layered 3D printer and filled concrete filled in an area partitioned by the 3D printed embedded form, The 3D printed embedded formwork has a partition wall made of a plurality of laminated material layers stacked on top of each other, The inner end of the laminate layer has a protruding portion that protrudes toward the inside of the partition wall more than the inner end of the laminate layer adjacent thereto above and / or below. A foundation structure made using 3D printed embedded formwork.

5. The protrusions are formed at a plurality of locations at predetermined intervals in a horizontal cross section of the partition wall. A foundation structure using a 3D printed embedded formwork as claimed in claim 3 or 4.

6. The foundation structure is a column foundation or a pile foundation. A foundation structure using a 3D printed embedded formwork according to any one of claims 1 to 4.

7. The foundation structure is a column foundation or a pile foundation. A foundation structure formed by the 3D printed embedded formwork described in claim 5.

8. A method for manufacturing a foundation using a 3D printed embedded form, comprising at least a 3D printed embedded form formed by a layered 3D printer and concrete filled into an area partitioned by the 3D printed embedded form, stacking a plurality of laminate layers upward to form a bulkhead to produce a 3D printed embedded form; and filling the area defined by the 3D printed embedded form with filling concrete. In the step of manufacturing the 3D printed embedded formwork, the laminated material layers are laminated in a concave-convex shape and the aspect ratio of the concave-convex shape is adjusted. A method for manufacturing a foundation using a 3D printed buried formwork.

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