Base plate and pedestal

Abstract

To provide a base plate and so on that excel in shear strength.SOLUTION: A base plate 3 has anchor bolt holes 7 as open holes arranged in the vicinity of the four corners. One end of a column 5 is connected to the top surface of the base plate 3. The anchor bolt hole 7 consists of a small-diameter part 9a being a hole with a relatively small diameter and a large-diameter part 9b being hole with a relatively large diameter. The small-diameter part 9a is formed in the top surface side of the base plate 3 while the large-diameter part 9b being formed in the bottom surface side of the base plate 3, that is, the anchor bolt hole 7's diameter is different in size between the upper part and the lower part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a base plate or the like to which a column is joined. [Background technology]

[0002] In the column-base structure of a structure, a base plate is joined to the bottom of the column, and the base plate is fixed to the concrete of the foundation, etc. with anchor bolts. At this time, mortar is filled between the base plate and the foundation.

[0003] In this way, when filling the gap between the base plate and the foundation with mortar, the mortar is also filled into the gap between the anchor bolt and the hole for inserting the anchor bolt. At this time, a method has been proposed for confirming that the mortar has been reliably filled into the anchor bolt hole (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-035313 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional methods, there are cases where the mortar does not fill the gap between the anchor bolt hole and the anchor bolt due to insufficient air escape or mortar flow area. Since the shear force on the base plate 3 is transmitted to the anchor bolt via the mortar, if a gap occurs between the anchor bolt and the anchor bolt hole, the shear force is not transmitted to the anchor bolt. This causes a decrease in the shear strength of the column base structure.

[0006] The present invention has been made in view of the above problems, and has an object to provide a base plate or the like having excellent shear strength. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the first invention is a base plate to which a column is joined, characterized in that an anchor bolt hole, which is a through hole, is formed at a predetermined position in the base plate, the anchor bolt hole has a small diameter portion, which is a hole with a relatively small diameter, and a large diameter portion, which is a hole with a relatively large diameter, the small diameter portion being formed on the upper surface side of the base plate, and the large diameter portion being formed on the lower surface side of the base plate.

[0008] The small diameter portion may have a constant diameter in the depth direction, and the large diameter portion may have a tapered portion whose diameter gradually decreases as it approaches the small diameter portion.

[0009] The large diameter portion may be a constant diameter portion having a substantially constant diameter to a predetermined depth on the lower surface side of the base plate, and the tapered portion may be formed between the constant diameter portion and the small diameter portion.

[0010] It is desirable that the difference in diameter between the small diameter portion and the large diameter portion be 4 mm or more.

[0011] It is desirable that the depth of the large diameter portion from the lower surface of the base plate is 10 mm or more and 50% or less of the thickness of the base plate.

[0012] According to the first aspect of the present invention, a small diameter portion with a relatively small diameter is formed at the top of the anchor bolt hole, and a large diameter portion with a relatively large diameter is formed at the bottom of the anchor bolt hole, so that a clearance between the anchor bolt and the anchor bolt hole can be secured at least in the large diameter portion. This allows mortar to be reliably filled between the anchor bolt and the anchor bolt hole. This allows the shear force generated in the base plate to be reliably transmitted to the anchor bolt.

[0013] In addition, by forming a tapered section in the large diameter section where the diameter gradually decreases as it approaches the small diameter section, the tapered section functions as a guide to the small diameter section, making it easier to insert the tip of the anchor bolt fixed in the foundation into the anchor bolt hole in the base plate.

[0014] Furthermore, by forming a constant diameter section with a predetermined depth below the large diameter section and a tapered section between the constant diameter section and the small diameter section, the constant diameter section can more reliably transmit shear force in a direction perpendicular to the axis of the anchor bolt, and the tapered section can also exhibit a guide function.

[0015] Furthermore, if the difference in diameter between the small diameter portion and the large diameter portion is 4 mm or more, a gap of 2 mm or more can be secured at least between the anchor bolt and the inner surface of the large diameter portion, allowing mortar to be reliably filled into the gap.

[0016] Furthermore, by making the depth of the large diameter part from the underside of the base plate 10 mm or more, the shear force generated in the base plate can be reliably transmitted to the anchor bolt. Furthermore, by making the depth of the large diameter part 50% or less of the thickness of the base plate, the axial force generated when the nut is tightened onto the anchor bolt can be reliably transmitted to the base plate via the nut.

[0017] The second invention is a column base structure using the base plate according to the first invention, characterized in that an anchor bolt is inserted into the anchor bolt hole and fixed to the foundation, the anchor bolt is fixed with a nut on the upper surface of the base plate, mortar is filled between the base plate and the foundation, and the mortar is filled in at least the large diameter portion.

[0018] It is desirable that the diameter of the small diameter portion be smaller than the diameter of the nut.

[0019] According to the second aspect of the present invention, the large diameter portion is filled with mortar, so that the shear force generated in the base plate can be reliably transmitted to the anchor bolt.

[0020] Furthermore, by making the diameter of the small diameter portion smaller than the diameter of the nut, the axial force generated when the nut is tightened onto the anchor bolt can be reliably transmitted to the base plate via the nut. [Effects of the Invention]

[0021] According to the present invention, a base plate or the like having excellent shear strength can be provided. [Brief explanation of the drawings]

[0022] [Figure 1] (a) is a side view of the column member 1, and (b) is a cross-sectional view taken along line AA of (a). [Figure 2] (a) is a cross-sectional view taken along line BB in Figure 1(b), and (b) is an enlarged view of part C in (a). [Figure 3] 1(a) and 1(b) are diagrams showing the construction process of the column base structure 10. [Figure 4] Enlarged view of part J in Figure 3(b). [Figure 5] 10(a) to 10(c) are diagrams showing examples of variations in the shape of the anchor bolt hole 7. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a pillar member 1 according to an embodiment of the present invention will be described. Fig. 1(a) is a side view showing the pillar member 1, and Fig. 1(b) is a cross-sectional view taken along line AA in Fig. 1(a). The pillar member 1 is mainly composed of a base plate 3 and a pillar 5.

[0024] The base plate 3 is a generally rectangular plate-like member made of, for example, steel in plan view. Anchor bolt holes 7, which are through holes, are provided near the four corners of the base plate 3. Anchor bolts, which will be described later, are inserted into the anchor bolt holes 7. One end of a pillar 5 is joined to the top surface of the base plate 3. The pillar 5 is, for example, a square steel pipe.

[0025] Figure 2(a) is a cross-sectional view taken along line BB in Figure 1(b), and Figure 2(b) is an enlarged view of part C in Figure 2(a). As shown in Figure 2(b), anchor bolt hole 7 is composed of small diameter portion 9a, which is a hole with a relatively small diameter, and large diameter portion 9b, which is a hole with a relatively large diameter. Small diameter portion 9a is formed on the upper surface of base plate 3, and large diameter portion 9b is formed on the lower surface of base plate 3. In other words, anchor bolt hole 7 has different hole sizes at the top and bottom.

[0026] In this embodiment, the small diameter portion 9a has a constant diameter H, and the large diameter portion 9b has a constant diameter I. In this case, the difference between the diameter H of the small diameter portion 9a and the diameter I of the large diameter portion 9b is preferably 4 mm or more, and more preferably 6 mm or more. In other words, the small diameter portion 9a and the large diameter portion 9b are formed concentrically, and the large diameter portion 9b is larger than the small diameter portion 9a by 2 mm or more over the entire circumference. This ensures the filling properties of the mortar, which will be described later.

[0027] Furthermore, it is desirable that the depth E of the large diameter portion 9b from the underside of the base plate 3 be 10 mm or more. Since the large diameter portion 9b becomes the portion filled with mortar, as described below, by making the depth E of the large diameter portion 9b 10 mm or more, the height of the mortar filled can be 10 mm or more. In this way, the inventors of the present invention have noticed that even if mortar is not filled throughout the entire thickness of the base plate 3 around the anchor bolt 11 inside the anchor bolt hole 7, shear force is sufficiently transmitted, and have arrived at the present invention.

[0028] Furthermore, the depth E of the large diameter portion 9b is preferably 50% or less, and more preferably 40% or less, of the thickness D of the base plate 3. In other words, the depth of the small diameter portion 9a from the upper surface of the base plate 3 is preferably 50% or more of the thickness D of the base plate 3. A nut (and washer) for fixing the anchor bolt 11 is disposed on the upper surface of the base plate 3, and the force from the nut needs to be received by the upper surface of the base plate 3; however, if the depth of the small diameter portion 9a is shallow, the base plate 3 may not be strong enough to withstand the force received from the nut when the nut is tightened.

[0029] In order to make the depth E of the large diameter portion 9b 10 mm or more and to make the depth E of the large diameter portion 9b 50% or less of the thickness D of the base plate 3, the thickness of the base plate 3 is 30 mm or more.

[0030] Next, we will explain the construction method of a column base structure using a column member 1 (base plate 3). First, as shown in Figure 3(a), the anchor bolt 11 is fixed to the foundation 14, and the column member 1 is installed from above, aligning it with the position of the anchor bolt 11. At this time, the anchor bolt 11 is inserted into the anchor bolt hole 7. After that, the anchor bolt 11 and the column member 1 are fixed together with a nut 13 and a washer 15.

[0031] Next, formwork 17 is installed at a predetermined distance from base plate 3 so as to surround the periphery of base plate 3. Note that base plate 3 is installed with a gap between it and foundation 14 using level mortar.

[0032] In this state, mortar is poured into the gap between the formwork 17 and the base plate 3. The mortar fills the gap between the base plate 3 and the foundation 14, and also fills the gap between the base plate 3 and the anchor bolt 11 at least in the large diameter portion 9b inside the anchor bolt hole 7.

[0033] Fig. 3(b) is a diagram showing the column base structure 10 after the mortar has solidified and the formwork 17 has been removed, and Fig. 4 is an enlarged view of part J in Fig. 3(b). The column base structure 10 is fixed to the foundation 14 by inserting anchor bolts 11 into the anchor bolt holes 7, and the anchor bolts 11 are fixed with nuts on the upper surface of the base plate 3. Furthermore, mortar 19 is filled between the base plate 3 and the foundation 14, and the mortar 19 is filled at least in the large diameter portion 9b.

[0034] As shown in Figure 4, when mortar 19 is filled between the anchor bolt 11 and the inner surface of the large diameter portion 9b and around the entire circumference of the anchor bolt 11, the force from the base plate 3 can be transmitted to the anchor bolt 11. For example, when a shear force K is generated in the horizontal direction on the base plate 3, force L is transmitted from the base plate 3 to the anchor bolt 11 via the mortar 19 in either direction. This makes it possible to increase the shear resistance.

[0035] The axial force of the anchor bolt 11 is transmitted from the nut 13 to the base plate 3. For this reason, it is desirable that the diameter H of the small diameter portion 9a (see FIG. 2(b)) is smaller than the diameter M of the nut 13 (see FIG. 4). This ensures that the force from the nut 13 is transmitted to the base plate 3. It is desirable that the diameter of the large diameter portion 9b is sufficiently larger than the diameter of the nut 13, and furthermore, larger than the diameter of the washer 15.

[0036] Furthermore, as described above, if the depth of the small diameter portion 9a from the top surface of the base plate 3 is 50% or more of the thickness D of the base plate 3, deformation of the base plate 3 can be suppressed even when the nut 13 is tightened. This makes it possible to sufficiently bear the force from the nut 13 and further improve the filling property of the mortar.

[0037] As described above, according to this embodiment, by forming the large diameter portion 9b below the anchor bolt hole 7, it is possible to ensure a sufficient clearance between the anchor bolt 11 and the inner surface of the anchor bolt hole 7. This makes it possible to reliably fill the periphery of the anchor bolt 11 with mortar 19. This makes it possible to reliably transmit the shear force from the base plate 3 to the anchor bolt 11 from any direction, thereby increasing the shear resistance.

[0038] Furthermore, by setting the depth of the large diameter portion 9b from the lower surface of the base plate 3 to 10 mm or more, it is possible to transmit shear force from the base plate 3 to the anchor bolt 11 over a thickness of at least 10 mm. Therefore, it is possible to sufficiently transmit the shear force from the base plate 3 to the anchor bolt 11.

[0039] Furthermore, by making the diameter of small diameter portion 9a smaller than the diameter of nut 13 and ensuring that small diameter portion 9a is sufficiently deep, the force from nut 13 can be fully borne by base plate 3 when nut 13 is tightened. Even in this case, the diameter of large diameter portion 9b is sufficiently large compared to nut 13, etc., so mortar 19 can be reliably filled around the entire circumference of anchor bolt 11.

[0040] Furthermore, since the large diameter portion 9b is formed on the underside of the base plate 3, it is easy to insert the anchor bolt 11 into the anchor bolt hole 7. As mentioned above, when constructing the column base structure, after the anchor bolt 11 is fixed to the foundation, the column member 1 is lifted and the base plate 3 is installed in accordance with the position of the anchor bolt 11. For this reason, the larger the anchor bolt hole 7, the easier it is to insert the anchor bolt 11 into the anchor bolt hole 7.

[0041] In the above-described embodiment, a step is formed between the small diameter portion 9a and the large diameter portion 9b in the anchor bolt hole 7, but this is not limiting. For example, as shown in Fig. 5(a), the large diameter portion 9b may be tapered.

[0042] In the example shown in FIG. 5(a), the small diameter portion 9a has a constant diameter in the depth direction, but the large diameter portion 9b has a tapered portion in which the diameter gradually decreases as it approaches the small diameter portion 9a. In other words, the large diameter portion 9b does not have a constant diameter in the depth direction. Also, the top of the large diameter portion 9b is the smallest diameter portion of the tapered shape, and this diameter is approximately the same as the small diameter portion 9a. Therefore, no step is formed between the large diameter portion 9b and the small diameter portion 9a.

[0043] This facilitates the process of inserting the anchor bolt 11 into the anchor bolt hole 7. As mentioned above, the anchor bolt 11 is inserted from below into the anchor bolt hole 7, so if there is a step, the tip of the anchor bolt 11 will get caught on the step, making it difficult to install the pillar member 1. In contrast, by making the large diameter portion 9b tapered, the tip of the anchor bolt 11 is guided into the small diameter portion 9a, making alignment easier.

[0044] Furthermore, such a tapered shape does not have to be a linear shape. For example, as shown in Fig. 5(b), the tapered portion of the large diameter portion 9b may be a curved tapered shape in which the diameter gradually decreases as it approaches the small diameter portion 9a.

[0045] Also, instead of making the entire large diameter portion 9b tapered, only a portion of it may be tapered. For example, as shown in Figure 5(c), on the underside of the base plate 3, a constant diameter portion with a substantially constant diameter may be formed to a predetermined depth of the large diameter portion 9b, and a tapered portion whose diameter gradually decreases as it approaches the small diameter portion 9a may be formed between this constant diameter portion and the small diameter portion 9a. This configuration can also achieve the same effects as those in Figures 5(a) and 5(b).

[0046] 5(c), a constant diameter portion is formed in the large diameter portion 9b. As described above, the shear force of the base plate 3 is transmitted from the inner surface of the large diameter portion 9b to the anchor bolt 11 via the mortar 19. At this time, by orienting the inner surface of the large diameter portion 9b perpendicular to the direction of the shear force, the inner surface of the large diameter portion 9b and the outer surface of the anchor bolt 11 face each other in parallel, and the shear force can be transmitted more efficiently in the direction perpendicular to the axial direction of the anchor bolt 11.

[0047] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not limited to the above-described embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas described in the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention.

[0048] For example, the cross section of the pillar 5 is not limited to a substantially rectangular shape, but may be circular or H-shaped. Furthermore, the arrangement of the anchor bolt holes 7 is not limited to one near each of the four corners of the base plate 3, and the positions and number of the anchor bolt holes 7 are not particularly limited. [Explanation of symbols]

[0049] 1……Column member 3...Base plate 5... Pillar 7...Anchor bolt hole 9a……Small diameter part 9b...Large diameter section 10……Column base structure 11...Anchor bolt 13...Nut 14……Fundamentals 15...Washer 17...Formwork 19...Mortar

Claims

1. A base plate to which the column is joined, Anchor bolt holes, which are through holes, are formed at predetermined positions on the base plate. a base plate characterized in that the anchor bolt hole has a small diameter portion that is a hole with a relatively small diameter and a large diameter portion that is a hole with a relatively large diameter, the small diameter portion being formed on the upper surface side of the base plate and the large diameter portion being formed on the lower surface side of the base plate.

2. 2. The base plate according to claim 1, wherein the small diameter portion has a constant diameter in the depth direction, and the large diameter portion has a tapered portion whose diameter gradually decreases as it approaches the small diameter portion.

3. 3. The base plate according to claim 2, wherein the large diameter portion is a constant diameter portion having a substantially constant diameter to a predetermined depth on the lower surface side of the base plate, and the tapered portion is formed between the constant diameter portion and the small diameter portion.

4. 2. The base plate according to claim 1, wherein the difference in diameter between the small diameter portion and the large diameter portion is 4 mm or more.

5. 2. The base plate according to claim 1, wherein the depth of the large diameter portion from the lower surface of the base plate is 10 mm or more and 50% or less of the thickness of the base plate.

6. A column base structure using the base plate according to any one of claims 1 to 5, Anchor bolts are inserted into the anchor bolt holes and fixed to the foundation, and the anchor bolts are fixed with nuts on the upper surface of the base plate, A column base structure characterized in that mortar is filled between the base plate and the foundation, and the mortar is filled at least in the large diameter portion.

7. The column base structure according to claim 6, wherein the diameter of the small diameter portion is smaller than the diameter of the nut.

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