Fixing structure of seismic isolation foundation

Abstract

To reduce the amount of work required for installation compared to using rod-shaped members such as reinforcing bars or stud bolts as fixing members.SOLUTION: A fixing structure of a seismic isolation foundation includes: a support plate 10; a precast concrete seismic isolation foundation 20 placed on the support plate 10 and having a seismic isolation device 22 attached thereto; a plurality of perforated steel plate dowels 30 whose lower parts are embedded in the support plate 10; a plurality of insertion holes 24 opened on the underside of the seismic isolation foundation 20, into which upper parts of the perforated steel plate dowels 30 are inserted; and filling material 40 filled in the insertion holes 24.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fixing structure for a seismic isolation foundation. [Background technology]

[0002] The following Patent Document 1 shows a seismic isolation foundation structure in which reinforcing bars with anchoring plates protruding from a foundation slab are inserted into through holes in a precast concrete panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-32759 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the seismic isolation foundation structure shown in the above Patent Document 1, a precast concrete plate, which is the foundation member of the seismic isolation device, is fixed to the foundation slab, which is the supporting structure, by reinforcing bars with anchoring plates. With this configuration, it is necessary to ensure the necessary shear strength by using reinforcing bars. As the number of reinforcing bars increases, the number of through holes also increases, and the labor required for grout filling also increases, which makes it difficult to manufacture and construct the foundation members.

[0005] In consideration of the above, the present invention aims to provide a fixing structure for a seismic isolation foundation that can reduce construction labor compared to using rod-shaped members such as reinforcing bars and stud bolts as fixing members. [Means for solving the problem]

[0006] The fixing structure of the seismic isolation foundation of claim 1 comprises a support plate, a precast concrete seismic isolation foundation placed on the support plate and to which a seismic isolation device is attached, a plurality of perforated steel plate dowels having their lower parts embedded in the support plate, a plurality of insertion holes opened on the underside of the seismic isolation foundation and into which the upper parts of the perforated steel plate dowels are inserted, and filling material filled into the insertion holes.

[0007] In the fixed structure of the seismic isolation foundation of claim 1, the support plate and the seismic isolation foundation made of precast concrete are fixed using perforated steel plate dowels and filler. The perforated steel plate dowels can exert shear strength from an early stage by filling the through holes with filler. For example, the filler can exert shear strength even when deformed in the elastic deformation range.

[0008] In contrast, rod-shaped members such as reinforcing bars and stud bolts exert shear strength after the filler material is plastically deformed. Therefore, in this embodiment using perforated steel plate dowels, the strength is improved compared to when rod-shaped members such as reinforcing bars and stud bolts are used, and the number of perforated steel plate dowels and insertion holes can be reduced. In addition, the labor required to fill the insertion holes with the filler material can also be reduced.

[0009] In this manner, in the present embodiment, in which the support plate and the precast concrete seismic isolation foundation are fixed using perforated steel plate dowels, construction work can be reduced compared to the use of rod-shaped members such as reinforcing bars or stud bolts as fixing members.

[0010] The fixing structure of the seismic isolation foundation of claim 2 comprises a support plate, a precast concrete seismic isolation foundation placed on the support plate and to which a seismic isolation device is attached, a plurality of perforated steel plate dowels having their upper parts embedded in the seismic isolation foundation, a plurality of insertion holes opened on the upper surface of the support plate into which the lower parts of the perforated steel plate dowels are inserted, and filling material filled into the insertion holes.

[0011] In the fixing structure of the seismic isolation foundation of claim 2, the support plate and the precast concrete seismic isolation foundation are fixed using perforated steel plate dowels and filler, as in the fixing structure of the seismic isolation foundation of claim 1. Therefore, in this embodiment, the construction work can be reduced compared to the case where rod-shaped members such as reinforcing bars and stud bolts are used as fixing members. In addition, since the perforated steel plate dowels do not protrude from the support plate, they are unlikely to interfere with other work.

[0012] The fixing structure for a seismic isolation foundation of claim 3 is the fixing structure for a seismic isolation foundation of claim 1 or 2, in which, in a plan view, the long sides of the multiple perforated steel plate dowels are arranged so as to follow multiple different angles.

[0013] In the fixed structure of the seismic isolation foundation of claim 3, the long sides of the multiple perforated steel plate dowels are arranged along multiple different angles. Therefore, each perforated steel plate dowel is in the strong axis direction with respect to the shaking direction of a specific earthquake. This allows it to exert shear resistance against earthquake forces acting in different directions.

[0014] The fixing structure for a seismic isolation foundation according to claim 4 is the fixing structure for a seismic isolation foundation according to claim 1, wherein a spiral reinforcement surrounding the insertion hole is embedded in the seismic isolation foundation.

[0015] In the fixed structure of the seismic isolation foundation of claim 4, a spiral reinforcement is embedded in the seismic isolation foundation, surrounding the insertion hole. This makes it possible to suppress the occurrence of cracks in the concrete when the concrete is pressed through the filler material by the perforated steel plate dowel. Effect of the Invention

[0016] According to the present invention, construction work can be reduced compared to when rod-shaped members such as reinforcing bars or stud bolts are used as fixing members. [Brief description of the drawings]

[0017] [Figure 1]FIG. 1A is a cross-sectional view showing the fixing structure of a seismic isolation foundation according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line BB in FIG. [Diagram 2] FIG. 2A is a perspective view showing a perforated steel plate dowel used in the fixing structure of a seismic isolation foundation according to an embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line BB in FIG. [Diagram 3] FIG. 1A is a perspective view showing a modified example of a perforated steel plate dowel used in the fixing structure of a seismic isolation foundation according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line BB in FIG. [Figure 4] (A) is a cross-sectional view showing the state in which the lower part of the perforated steel plate dowel is embedded in the support plate in the fixed structure of the seismic isolation foundation according to an embodiment of the present invention, (B) is a cross-sectional view showing the state in which the seismic isolation foundation has been installed, and (C) is a cross-sectional view showing the state in which the insertion holes of the seismic isolation foundation have been filled with filling material. [Diagram 5] 1A is a top view showing a modified example in which the insertion hole is formed into a rectangular shape, FIG. 1B is a top view showing a modified example in which the insertion hole is formed into a circular shape and the spiral streaks are omitted, and FIG. 1C is a top view showing an example in which the insertion hole is formed into a circular shape and spiral streaks are provided. [Figure 6] 1 is a cross-sectional view showing a modified example in which an insertion hole is formed in a support plate in a fixed structure of a seismic isolation foundation according to an embodiment of the present invention. [Figure 7] (A) is a cross-sectional view showing the state in which an insertion hole has been formed in the support plate in a fixed structure of a seismic isolation foundation relating to a modified example of the present invention, (B) is a cross-sectional view showing the state in which the seismic isolation foundation has been installed, and (C) is a cross-sectional view showing the state in which the filling material has been filled into the insertion hole in the support plate. [Figure 8] (A) is a graph showing the relationship between the relative displacement of two objects connected by a shear connector and the shear force acting on the shear connector, and (B) is a graph for small displacements. [Figure 9] 13 is another graph showing the relationship between the relative displacement of two objects connected by a shear connector and the shear force acting on the shear connector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a fixing structure of a seismic isolation foundation according to an embodiment of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in each drawing are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and may be present in multiple numbers.

[0019] In addition, explanations of configurations and symbols that are duplicated in each drawing may be omitted. Note that the present disclosure is not limited to the following embodiments, and may be implemented by making appropriate modifications, such as omitting configurations, replacing them with different configurations, or combining one embodiment and various modified examples, within the scope of the purpose of the present disclosure.

[0020] In each drawing, the directions indicated by the arrows X and Y are directions along a horizontal plane and are perpendicular to each other. The direction indicated by the arrow Z is a direction along the vertical direction (up and down direction). The directions indicated by the arrows X, Y, and Z in each drawing are assumed to be mutually consistent.

[0021] <Fixed structure of seismic isolation foundation> The fixing structure of a seismic isolation foundation according to an embodiment of the present invention is a structure for fixing a seismic isolation foundation 20 to a support plate 10 shown in Fig. 1(A). This fixing structure is formed with the support plate 10, the seismic isolation foundation 20, a perforated steel plate dowel 30, a filler material 40, and a spiral reinforcement 50.

[0022] (Support board) The support plate 10 is, for example, a building foundation such as a pressure plate, and is made of concrete.

[0023] (Seismic isolation foundation) The seismic isolation base 20 is a foundation made of precast concrete to which a seismic isolation device 22 is fixed. As the seismic isolation device 22, various devices such as laminated rubber bearings, sliding bearings, oil dampers, and steel dampers can be used.

[0024] An insertion hole 24 is formed in the seismic isolation base 20. The insertion hole 24 is a cylindrical hole formed from the upper end surface to the lower end surface of the seismic isolation base 20. As shown in Fig. 1(B) , a plurality of insertion holes 24 are arranged on the outer periphery of the seismic isolation base 20, surrounding the base plate 22A of the seismic isolation device 22. As an example, the insertion hole 24 has a hole diameter of 130 mm.

[0025] (Perforated steel plate dowel) The perforated steel dowel 30 is a steel plate material as shown in Figures 2(A) and (B), and is used as a shear connector capable of transmitting shear force between the support plate 10 and the seismic isolation foundation 20. The perforated steel dowel 30 has through holes 32 formed at both the top and bottom. A rib 34 is formed on the outer edge of the through hole 32.

[0026] As an example, the thickness of the perforated steel dowel 30 is 6 mm, the diameter of the through hole 32 is 50 mm, the height of the rib 34 (the protruding height from the surface of the perforated steel dowel 30) is 15 mm, and the width (the length of the long side in a plan view) is 100 mm. These values ​​can be changed as appropriate.

[0027] It should be noted that the rib 34 does not necessarily have to be formed, and as shown in Figures 3(A) and (B), the perforated steel plate connector 30 may be configured without the rib 34. In addition, the number of through holes 32 is not particularly limited, but in this embodiment, one each at the upper and lower parts, a total of two through holes are formed.

[0028] As shown in Fig. 1(A), the lower part of the perforated steel dowel 30 is embedded in the support plate 10. The inside of the through hole 32 formed in the lower part of the perforated steel dowel 30 is filled with concrete that forms the support plate 10.

[0029] On the other hand, the upper part of the perforated steel dowel 30 protrudes upward from the upper surface of the support plate 10 and is inserted into the insertion hole 24 of the seismic isolation foundation 20. The inside of the through hole 32 formed in the upper part of the perforated steel dowel 30 is filled with the filler material 40 in the insertion hole 24.

[0030] 1(B), a perforated steel dowel 30 is provided for each insertion hole 24. The perforated steel dowel 30 is arranged with its long side (long side in plan view) aligned along the X direction on the inside of the insertion holes 24 aligned along the X direction. On the other hand, the perforated steel dowel 30 is arranged with its long side aligned along the Y direction on the inside of the insertion holes 24 aligned along the Y direction. Furthermore, inside the insertion hole 24 at the corner, the long side is inclined at 45° with respect to the X direction and the Y direction.

[0031] (Spiral muscles) The spiral reinforcement 50 is a reinforcing bar that is embedded in the seismic isolation base 20 while surrounding the insertion hole 24. The spiral reinforcement 50 is wound around the insertion hole 24 in a spiral shape.

[0032] (filling material) The filler 40 is a grout material that is filled into the insertion hole 24 with the perforated steel plate dowel 30 inserted therein. As an example, a grout material that has a higher compressive strength, a lower Young's modulus, and a higher splitting tensile strength than the concrete that forms the seismic isolation base 20 can be used as this grout material.

[0033] The filler 40 is filled not only in the insertion holes 24 but also in the horizontal joints between the support plate 10 and the seismic isolation foundation 20.

[0034] (Construction method) The fixed structure of the seismic isolation foundation is constructed as follows: First, as shown in Fig. 4(A), the support plate 10 is constructed with the lower part of the perforated steel plate dowel 30 buried.

[0035] Next, as shown in Fig. 4(B), the seismic isolation foundation 20 is placed on the support plate 10 while inserting the perforated steel plate dowels 30 into the insertion holes 24. At this time, a spacer (not shown) is provided between the support plate 10 and the seismic isolation foundation 20 to ensure a gap V. In addition, a formwork (not shown) is placed around this gap.

[0036] 4(C), the filler 40 is injected from the injection hole 20A formed in the approximate center of the seismic isolation base 20. The filler 40 is injected from the bottom to the top into the insertion hole 24 through the gap V. This fixes the seismic isolation base 20 to the support plate 10.

[0037] <Action and Effects> In the fixing structure of the seismic isolation foundation according to an embodiment of the present invention, as shown in FIG. 1(A), a support plate 10 and a precast concrete seismic isolation foundation 20 are fixed using a perforated steel plate dowel 30 and a filler material 40.

[0038] The perforated steel connector 30 can exhibit shear strength from an early stage by filling the through holes 32 with the filler 40. For example, the shear strength can be exhibited even when the filler 40 is deformed in the elastic deformation range.

[0039] In contrast to this, when a rod-shaped member such as a reinforcing bar or a stud bolt is used instead of the perforated steel plate dowel 30, the filler 40 exerts a shear strength after being plastically deformed.

[0040] Figures 8(A) and (B) show the relationship between the relative displacement of two objects connected by a shear connector and the shear force acting on the shear connector (acting shear force / maximum shear force). The shear connectors used are a stud bolt with a shaft diameter of 22 mm (curve K1) and a perforated steel dowel with a thickness of 12 mm and a through hole diameter of 50 mm (curve K2).

[0041] As shown in these figures, the perforated steel dowel exhibits a large shear strength at a stage when the displacement is small compared to the stud bolt. In this way, the perforated steel dowel exhibits shear strength at an earlier stage than the stud bolt.

[0042] The relationship between the relative displacement of two objects connected by a shear connector and the shear force acting on the shear connector (acting shear force) is also shown in Figure 9. The shear connectors used are a stud bolt with a shaft diameter of 19 mm (curve K3) and a perforated steel dowel with a thickness of 6 mm and a through hole diameter of 50 mm (curve K4).

[0043] As shown in this figure, perforated steel plate connectors have a greater shear strength than stud bolts.

[0044] In this manner, in this embodiment using the perforated steel plate dowel 30, the bearing strength is improved compared to the case where a rod-shaped member such as a stud bolt is used. This makes it possible to reduce the number of perforated steel plate dowels 30 and insertion holes 24. In addition, the man-hours required to fill the insertion holes 24 with the filler material 40 can also be reduced.

[0045] Here, for example, there are cases where the seismic isolation base 20 is reused. In such cases, the seismic isolation base 20 is separated from the support plate 10 by core-removing the filler material 40 around the perforated steel plate dowel 30, for example, in the insertion holes 24. In such cases, by reducing the number of insertion holes 24, the amount of core-removal work can be reduced compared to the case where rod-shaped members such as reinforcing bars and stud bolts are used.

[0046] Furthermore, since the filler 40 can exert shear strength even when deformed within its elastic deformation range, the amount of shear deformation between the support plate 10 and the seismic isolation foundation 20 can be made larger than when rod-shaped members such as reinforcing bars or stud bolts are used.

[0047] In addition, in the perforated steel plate connector 30 of this embodiment, the ribs 34 are formed on the outer edges of the through holes 32, so that the bearing stress between the perforated steel plate connector 30 and the filler 40 is increased. This makes it possible to improve the shear strength compared to a case in which the ribs 34 are not present.

[0048] In this manner, in the present embodiment in which the support plate 10 and the precast concrete seismic isolation foundation 20 are fixed using perforated steel plate dowels 30, construction work can be reduced compared to the use of rod-shaped members such as reinforcing bars or stud bolts as fixing members.

[0049] In addition, in the fixed structure of the seismic isolation foundation according to the embodiment of the present invention, as shown in FIG. 1(B), a plurality of perforated steel plate dowels 30 are arranged with their long sides aligned along a plurality of different angles (X direction, Y direction, and 45° with respect to the X direction and Y direction).

[0050] Therefore, each of the perforated steel plate dowels 30 has a strong axis direction in the shaking direction of a specific earthquake, so that the multiple steel plate dowels 30 can exert shear resistance against earthquake forces acting in different directions.

[0051] For example, a perforated steel dowel 30 whose long side is aligned along the X direction has a strong axis direction in the shaking direction of the X direction and exhibits high shear strength. On the other hand, a perforated steel dowel 30 whose long side is aligned along the Y direction has a strong axis direction in the shaking direction of the Y direction and exhibits high shear strength. Furthermore, a perforated steel dowel 30 whose long side is at an angle of 45° to both the X and Y directions exhibits shear strength in both the shaking directions of the X and Y directions.

[0052] In addition, in the fixed structure of the seismic isolation foundation according to the embodiment of the present invention, the insertion hole 24 is a cylindrical hole and has a circular shape in a plan view. As a result, when the concrete of the seismic isolation foundation 20 is pressed from the perforated steel plate dowel 30 via the filler 40, cracks originating from the corners E of the insertion hole are less likely to occur, compared to a case in which an insertion hole 240 having a rectangular shape in a plan view as shown in Fig. 5(A), for example.

[0053] In addition, in the fixed structure of the seismic isolation foundation according to the embodiment of the present invention, as shown in Fig. 1, the spiral reinforcement 50 surrounding the insertion hole 24 is embedded in the seismic isolation foundation 20. As a result, when the concrete of the seismic isolation foundation 20 is pressed from the perforated steel plate dowel 30 via the filler 40, it is possible to suppress the occurrence of cracks in the concrete as shown in Fig. 5(C), compared to the case where the spiral reinforcement 50 is omitted as shown in Fig. 5(B).

[0054] <Modification> In the modification shown in FIG. 6, an insertion hole into which a perforated steel dowel 30 is inserted is formed in the support plate 10.

[0055] Specifically, the upper part of the perforated steel plate dowel 30 is embedded in the seismic isolation foundation 20. The inside of the through hole 32 formed in the upper part of the perforated steel plate dowel 30 is filled with concrete that forms the seismic isolation foundation 20.

[0056] On the other hand, the lower part of the perforated steel dowel 30 protrudes downward from the lower surface of the seismic isolation base 20 and is inserted into the insertion hole 14 of the support plate 10. The inside of the through hole 32 formed in the lower part of the perforated steel dowel 30 is filled with the filler material 40 in the insertion hole 14.

[0057] The spiral reinforcement 50 shown in Fig. 1 may be embedded around the insertion hole 14, or may be omitted. Fig. 6 shows an example in which the spiral reinforcement 50 is omitted.

[0058] The fixing structure of the seismic isolation foundation according to the modified example is constructed as follows: First, as shown in Fig. 7(A), a support plate 10 having an insertion hole 14 is constructed.

[0059] Next, as shown in Fig. 7(B), the seismic isolation foundation 20 is placed on the support plate 10 while inserting the perforated steel plate dowels 30 protruding downward from the underside of the seismic isolation foundation 20 into the insertion holes 14. At this time, a spacer (not shown) is provided between the support plate 10 and the seismic isolation foundation 20 to ensure a gap V. In addition, a formwork (not shown) is placed around this gap.

[0060] 7(C), the filler 40 is injected from the side of the seismic isolation base 20. The filler 40 is filled from above into the insertion holes 14 through the gaps V. This fixes the seismic isolation base 20 to the support plate 10.

[0061] In this embodiment as well, an injection hole 20A (see FIG. 4(C)) may be provided in the approximate center of the seismic isolation base 20, and the filler 40 may be injected through this injection hole 20A.

[0062] The fixed structure of the seismic isolation foundation of the modified example can also provide the same effect as that of the fixed structure of the seismic isolation foundation shown in Fig. 1. In addition, since the perforated steel plate dowels 30 do not protrude from the support plate 10 until the seismic isolation foundation 20 is delivered, walking and transportation work on the support plate 10 are easy to carry out.

[0063] (Other embodiments) 1(B), in the above embodiment, the long sides (long sides in plan view) of the perforated steel sheet connector 30 are arranged along the X direction inside the insertion holes 24 aligned along the X direction, and the long sides are arranged along the Y direction inside the insertion holes 24 aligned along the Y direction. Also, inside the insertion holes 24 at the corners, the long sides are arranged at an angle of 45° with respect to the X and Y directions.

[0064] However, the embodiment of the present invention is not limited to this, and the angles of the multiple perforated steel plate dowels 30 are each arbitrary. However, in order to exert shear strength against multiple shaking directions, it is preferable to provide at least two types, one whose long side is along the X direction and one whose long side is along the Y direction.

[0065] In addition, in the seismic isolation base 20 shown in Fig. 1, the spiral reinforcement 50 is embedded surrounding the insertion hole 24, but the embodiment of the present invention is not limited to this. For example, as shown in Fig. 5(B), the spiral reinforcement 50 may be omitted.

[0066] In the above embodiment, the insertion hole 24 is a cylindrical hole and has a circular shape in a plan view, but the embodiment of the present invention is not limited to this. For example, as shown in Fig. 5(A), an insertion hole 240 having a rectangular shape in a plan view may be formed.

[0067] In the above embodiment, a grout material having a higher compressive strength, a lower Young's modulus, and a higher splitting tensile strength than the concrete forming the seismic isolation base 20 is used as the filler 40, but the embodiment of the present invention is not limited to this. The physical properties of the grout may be changed appropriately depending on the required characteristics, or the same material as the concrete forming the seismic isolation base 20 may be used. In this way, the present invention can be embodied in various aspects. [Explanation of symbols]

[0068] 10 Support plate 14 Insertion hole 20 Seismic isolation foundation 22 Seismic isolation device 24 Insertion hole 30 Steel plate dowel 40 Filler 50 Spiral Muscles 240 Insertion hole

Claims

1. A support plate and a precast concrete seismic isolation foundation disposed on the support plate and to which a seismic isolation device is attached; A plurality of perforated steel plate dowels having lower portions embedded in the support plate; a plurality of insertion holes formed on a lower surface of the seismic isolation foundation and into which upper portions of the perforated steel plate dowels are inserted; A filler filled in the insertion hole; A fixed structure with a seismic isolation foundation.

2. A support plate and a precast concrete seismic isolation foundation disposed on the support plate and to which a seismic isolation device is attached; A plurality of perforated steel plate dowels having upper portions embedded in the seismic isolation foundation; a plurality of insertion holes formed on an upper surface of the support plate and into which the lower portions of the perforated steel plate connectors are inserted; A filler filled in the insertion hole; A fixed structure with a seismic isolation foundation.

3. The fixing structure for a seismic isolation foundation according to claim 1 or 2, wherein in a plan view, the long sides of the multiple perforated steel plate dowels are arranged so as to follow multiple different angles.

4. A spiral reinforcement surrounding the insertion hole is embedded in the seismic isolation foundation. The fixing structure of the seismic isolation foundation according to claim 1.

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