JP2009102899A - Structure of pedestal of building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a pedestal easily constructed, having excellent strength, and preventing the size of a foundation from being increased. <P>SOLUTION: An H-steel 20 comprising upper and lower flange parts 22, 21 and a web 23 connecting the upper and lower flange parts 22, 21 to each other is secured onto the bottom plate part 11 of a mat foundation formed by placing concrete. A column part 1 is secured to the upper flange part 22 through a pedestal fixture 30. The pedestal fixture 30 comprises a horizontal upper plate 32 secured to the lower end of the column part 1, a horizontal lower plate 31 secured to the upper surface of the upper flange part 22, and a connection plate 33 connecting between the upper and lower plates 32, 31 to each other and formed in a cross shape in plan view. The lower plate 31 and the upper flange part 22 are connected to each other on both sides of the web 23 through a bolt 34 vertically extending through the lower plate 31 and the upper flange part 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a structure at a connecting portion between a foundation of a building and a steel column, that is, a so-called column base structure of a building.

  As a structure for connecting the foundation of a building and a steel column, for example, there is a structure shown in FIG. In this column base structure, an anchor bolt 4 protruding upward is embedded in a foundation 10 made of reinforced concrete placed on the ground.

On the foundation 10, a lower end portion of the column portion 1 made of a hollow steel frame is connected. As for the connection, a horizontal flange 2 is welded and fixed to the lower end portion of the column portion 1, and a plurality of bolt holes 3 are formed in the flange 2.
While inserting the anchor bolt 4 into the bolt hole 3, the column portion 1 is supported on the foundation 10 so as not to fall down, and the nut 4a is fastened to the upper end of the anchor bolt 4 via a washer 4b or the like. Thus, the foundation 10 and the column part 1 are fixed together (for example, see Patent Document 1).

In addition, the foundation 10 shown in FIG. 6 (a) is constructed by placing concrete on the entire ground G under the building via the stone 6 to construct the bottom plate portion 11, and standing up from the bottom plate portion 11 upward. A so-called “solid foundation” provided with an upper part 12 is shown.
This type of “solid foundation” structure has a relatively large contact area with the ground G as compared to a structure called “single foundation” and “cloth foundation” as shown in FIG. The load of the building can be distributed and acted on the ground G over a wider area.
For this reason, it can be said that it is generally advantageous for unequal subsidence in medium-sized and small-scale buildings.

Also, there is a technique in which the upright portion 12 is composed of the H-shaped steel 20 for the purpose of simplifying the work of assembling the cast-in-place concrete for constructing the foundation 10, arranging reinforcing bars, placing concrete, and curing. It is disclosed.
For example, as shown in FIG. 7, the lower surface of the lower flange portion 21 of the H-shaped steel 20 is brought into close contact with the upper surface of the bottom plate portion 11 cast with concrete, and in that state, the anchor bolt 4 is interposed. The H-shaped steel 20 is fixed to form the raised portion 12 (see, for example, Patent Document 2).

JP-A-5-339992 (page 3, FIGS. 5 to 6) Japanese Patent Laid-Open No. 11-21911 (page 4, FIGS. 1 to 4)

When the upright portion 12 of the foundation 10 is constructed from the H-shaped steel 20, how to make a connection structure (column base structure) between the upright portion 12 and the column portion 1 becomes a problem.
For example, as shown in FIG. 7 (a), connecting plates 25, 25 extending upward are provided at both edges in the width direction of the upper flange portion 22 of the H-shaped steel 20, and the connecting plates 25, 25 and the column portion 1 are provided. There is a method of integrating the H-shaped steel 20 and the column part 1 with a horizontal bolt 26 penetrating the side surface of the steel plate.

  This method involves a processing operation for fixing the connection plate 25 to the H-shaped steel 20. The connection plate 25 can be fixed to the H-shaped steel 20 by, for example, factory welding or field welding.

  However, such a processing operation is complicated, and in particular, if a technique by factory welding is adopted, the H-shaped steel 20 is bulky, so that its transport efficiency is lowered. Moreover, if the technique by field welding is employ | adopted, it can be said that it is difficult to maintain the processing precision of a welding part.

  In addition, at the welding location between the connection plate 25 and the upper flange portion 22, the force that the connection plate 25 tends to fall in the direction indicated by the arrow A in FIG. 7 (a) (the width direction of the H-shaped steel 20) Sufficient strength is required. However, since the connection plate 25 is a flat plate material, the welded portion with the upper flange portion 22 is linear along the length direction B of the H-shaped steel 20. For this reason, it can be said that the welding direction is orthogonal to the force in the direction of the arrow A and is disadvantageous in strength.

In addition, since the column portion 1 is long in the vertical direction, once the column portion 1 is placed on the H-shaped steel 20, the nut cannot be tightened inside the column portion 1. For this reason, the said horizontal direction bolt 26 inserted in the bolt hole of the pillar part 1 requires the length which penetrates the pillar part 1 to the opposite side, and will tighten a nut in the other side of the pillar part 1. FIG. As described above, an increase in the length of the bolt is disadvantageous in terms of the strength of the column base structure.
For this reason, the column base structure which is easy to construct and has a structure superior in strength is desired.

  Therefore, a method of applying a conventional column base structure having a flange 2 at the lower end of the column portion 1 to an upright portion 12 made of an H-shaped steel 20 as shown in FIG. If the column part 1 is provided with the flange 2, it is not necessary to provide the connection plate 25 on the H-shaped steel 20.

  However, according to this method, as shown in FIG. 7B, the width L of the flange 2 is wider than the width B of the column portion 1, so that the flange 2 of the column portion 1 remains as it is as the upper flange of the H-shaped steel 20. The case where it protrudes from the part 22 is assumed. If the flange 2 protrudes from the upper flange portion 22 of the H-shaped steel 20, the load of the column portion 1 is not properly transmitted to the entire H-shaped steel 20 and the foundation 10, which is not preferable.

  Therefore, according to the length L of one side of the flange 2 (the length corresponding to the width direction of the H-shaped steel 20), for example, as shown in FIG. Must be secured. In other words, the H-shaped steel 20 must have a larger cross section than the cross section originally required based on the cross section of the column portion 1 and the load acting on the column portion 1.

  Further, when the width W of the upper flange portion 22 is increased and the point of application of the load from the flange 2 of the column portion 1 to the upper flange portion 22 is separated from the center line of the web 23 to the outside in the width direction of the H-shaped steel 20, 23, and the entire cross section of the H-shaped steel 20 including the lower flange portion 21 must be enlarged. It is uneconomical to increase the cross section of the H-shaped steel 20.

  Therefore, an object of the present invention is to provide a column base structure that is easy to construct, has superior strength, and does not increase the size of the foundation.

  In order to solve the above-mentioned problems, the present invention relates to an H-shaped steel comprising an upper and lower flange portion and a web connecting the upper and lower flange portions on a bottom plate portion of a solid foundation formed by placing concrete. In the building column base structure in which the lower end portion of the column portion perpendicular to the upper flange portion is fixed to the upper flange portion, the column base between the lower end portion of the column portion and the upper flange portion. A metal base is interposed between the horizontal upper plate fixed to the lower end of the column part, a horizontal lower plate fixed to the upper surface of the upper flange part, and a plane connecting the upper and lower plates. The lower plate and the upper flange portion are fixed via bolts penetrating the lower plate and the upper flange portion in the vertical direction. It adopted the pedestal structure of Tsukibutsu.

According to this configuration, since the connecting plate of the column base metal has a cross shape, the connecting portion between the connecting plate and the upper and lower plates is not a straight line in one direction, but a connection along a direction crossing the cross shape. Become. Similarly, the joint between the upper plate and the column part or the lower plate and the upper flange part is not a linear joint in one direction, but can be a planar joint or an annular joint surrounding the pillar part. . For this reason, the joint location can counter more strongly against the force in any direction in which the column portion tends to fall. That is, it can be set as the structure excellent in intensity | strength.
Moreover, according to this structure, the action point of the load from the column part to the upper flange part is not greatly separated from the center line of the web to the outside in the width direction of the H-shaped steel. For this reason, it is not necessary to enlarge the cross section of the whole H-shaped steel including a web and a lower flange part. For this reason, the foundation is not enlarged.
Since the connecting plate has a cross shape, the upper surface of the lower plate through which the bolt is inserted is at a position that can be reached from the outside. For this reason, bolts, nuts and the like can be easily tightened.

In this configuration, the bolt is preferably fixed on both sides of the web. Further, in each of the above-described configurations, the component member of the connecting plate having the cross shape is a plate material in which the surface direction of the plate surface is arranged in the length direction and the width direction of the H-shaped steel, and the bolt is It can be set as the structure provided in parallel with the said length direction and the width direction on both sides of the said connection plate.
This is preferable because the transmission of the load from the column base metal fitting to the upper flange portion becomes closer to the entire surface of the lower plate.
Further, if the constituent members of the connecting plate are arranged so that the surface direction of the plate surface is directed in the length direction and the width direction of the H-shaped steel, the column portion may fall in the length direction of the basic H-shaped steel. It is possible to have the maximum resistance against the force when the column part and the force when the column part tries to fall in the width direction of the basic H-shaped steel.

  Further, if a reinforcing rib that connects the upper flange portion and the lower flange portion is provided immediately below the column base metal fitting of the H-shaped steel, the rigidity of the H-shaped steel is increased directly below the portion where the column base metal fitting is provided. Can do. More preferably, the reinforcing rib is directly under the connecting plate.

  If the concrete that fills the space between the upper flange portion and the lower flange portion without gaps is placed on at least one side of the web immediately below the column base fitting of the H-shaped steel, the above Similarly to the above, the rigidity of the H-shaped steel can be increased immediately below the portion where the column base metal fitting is provided.

  As described above, the present invention includes a horizontal upper and lower plate and a connecting plate having a cross shape in plan view connecting the upper and lower plates between the lower end portion of the column portion and the upper flange portion of the basic H-shaped steel. Since the constructed column base metal fitting is interposed, it is possible to provide a column base structure that is easy to construct, has superior strength, and does not increase the size of the foundation.

  An embodiment will be described with reference to the drawings. In this embodiment, a foundation 10 having a “solid foundation” structure made of reinforced concrete is placed on the ground G via a gourd 6, and a steel pillar 1 having a square cross section is built on the foundation 10. The present invention relates to a column base structure in a connecting portion between the foundation 10 and the column portion 1 when the building is constructed.

The structure of the foundation 10 includes a bottom plate portion 11 made of concrete provided in a plane along the ground G, and an upright portion 12 rising from the bottom plate portion 11.
The bottom plate portion 11 has a reinforcing bar a. An anchor bolt 4 that protrudes upward is embedded in the bottom plate portion 11, and an upper end of the anchor bolt 4 protrudes from the upper surface of the bottom plate portion 11.

  The upright portion 12 is constituted by an H-shaped steel 20 fixed on the bottom plate portion 11. The H-shaped steel 20 has an H-shaped cross section including upper and lower flange portions 22 and 21 and a web 23 that connects the upper and lower flange portions 22 and 21.

When fixing the H-shaped steel 20 to the bottom plate portion 11, the upper flange portion 22 faces upward while the upper end of the anchor bolt 4 is inserted into the bolt hole provided in the lower flange portion 21 of the H-shaped steel 20. Thus, the H-shaped steel 20 is placed on the bottom plate part 11. By tightening the nut 4 a to the anchor bolt 4, the upper surface of the bottom plate portion 11 and the lower surface of the lower flange portion 21 of the H-shaped steel 20 are brought into close contact with each other, and the H-shaped steel 20 is fixed on the bottom plate portion 11.
Depending on the use and structure of the building, when the lower surface of the lower flange portion 21 of the H-shaped steel 20 is brought into close contact with the bottom plate portion 11, only a part thereof, for example, only a portion close to the anchor bolt 4 is provided. The case where it adheres is considered.

  As shown in FIG. 1, the column portion 1 is fixed on the H-shaped steel 20 via a column base metal 30. In addition, the code | symbol 8 shown in FIG. 1 is a gusset plate, and the code | symbol 9 is an oblique material which connects the pillar parts 1 mutually.

  The column base 30 includes a horizontal upper plate 32 that is welded and fixed to the lower end portion of the column portion 1, a horizontal lower plate 31 that is bolted to the upper surface of the upper flange portion 22, and the upper and lower plates 32 and 31. It is comprised with the connection plate 33 of the up-down direction which comprises the planar view cross shape which connects between.

  The upper plate 32 protrudes slightly outside the outer peripheral surface of the column portion 1 at the lower end portion of the column portion 1, and the upper plate 32 and the lower end portion of the column portion 1 are all around the column portion 1. They are joined by fillet welding. The connecting plate 33 is joined to the upper and lower plates 32 and 31 by fillet welding over the entire length (see FIG. 4). In any welding location, the welding position, the welding length, the welding depth, and the like can be set as appropriate.

These welds can all be field welds or all factory welds. Moreover, only welding with the column part 1 can also be made into site construction.
If only the welding of the upper and lower plates 32, 31 and the connecting plate 33 is a factory welding and the welding of the column base 30 and the column part 1 is an on-site welding, the transportation efficiency of the column part 1 is not hindered. . This is because when the column base metal fitting 30 is attached to the lower end portion of the column portion 1, the column base metal fitting 30 is obstructive and difficult to carry.
Further, if the column base metal fitting 30 is factory-welded, there is an advantage that the accuracy can be relatively improved as compared with the case of field welding. Thus, if the column base metal fitting 30 is factory-welded, the column base metal fitting 30 can be applied to a column base structure of various buildings as a general-purpose building material.

  Next, the lower plate 31 and the upper flange portion 22 are fixed via bolts 34 penetrating the lower plate 31 and the upper flange portion 22 in the vertical direction. The number of bolts 34 can be freely set. In this embodiment, four bolts 34 are used, and two bolts 34 are arranged on both sides of the H-shaped steel 20 in the width direction with the web 23 interposed therebetween. Yes.

Further, the component members of the connecting plate 33 having the cross shape are plate members 33a arranged in the length direction of the H-shaped steel 20 and plate members 33b and 33b arranged in the width direction. The bolt 34 is provided in parallel in the length direction and the width direction of the H-shaped steel 20 with the connecting plate 33 interposed therebetween. That is, one bolt 34 is disposed in each region of the lower plate 31 partitioned into four sections by the plate members 33a and 33b of the connection plate 33 (see FIG. 3).
For this reason, the transmission of the load from the column part 1 to the H-shaped steel 20 is likely to act evenly over the entire surface of the lower plate 31.

In order to insert the bolt 34, the bolt hole 32 a formed in the upper flange portion 22 of the H-shaped steel 20 is drilled in the field according to the hole position of the bolt hole 31 a of the lower plate 31 of the column base metal 30. be able to.
Moreover, the bolt hole 31a formed in the lower plate 31 may be drilled in the field, or may be drilled in the factory when the bolt interval at the column base to be used is determined in advance.

As shown in FIGS. 1 and 3, reinforcing ribs 24 that connect the upper flange portion 22 and the lower flange portion 21 are provided immediately below the column base fitting 30 attached in this way.
As shown in FIG. 1C, the reinforcing ribs 24 are provided on both sides of the H-shaped steel 20 across the web 23, and as shown in FIGS. It is provided at a total of three locations immediately below the end edge (the end edge in the length direction of the H-shaped steel 20) and in the center thereof.

  For this reason, when the force transmitted from the lower plate 31 causes the upper flange portion 22 of the H-shaped steel 20 to twist from the horizontal state to the slightly inclined state with respect to the web 23, the reinforcing rib 24 is The upper flange portion 22 can be countered against the force so as not to twist. Therefore, the support of the column part 1 and the upright part 12 is stronger.

The number of the reinforcing ribs 24 can be freely set, and the position is preferably directly below the lower plate 31 or as close as possible to the lower plate 31.
In particular, it is more desirable that the reinforcing ribs 24 are directly below the connecting plate 33, and the cross-shaped structural members (the plate members 33a and 33b) of the connecting plate 33 are the length of the H-shaped steel 20 as in this embodiment. In the case where the reinforcing ribs 24 are disposed in a direction perpendicular to the direction and the length direction thereof, the reinforcing ribs 24 are arranged in the direction perpendicular to the length direction as shown in FIGS. It is more effective to provide it directly under the plate members 33b and 33b). In FIGS. 1A and 1B, the reinforcing ribs 24 are disposed directly below the entire length of the constituent members (the plate members 33b and 33b) in the direction orthogonal to the length direction.

After fixing the column portion 1 on the H-shaped steel 20 in this manner, the upper flange portion 22 and the lower portion of the H-shaped steel 20 and the lower flange 22 are located directly below the column base metal fitting 30 and on the outside of the building with the web 23 interposed therebetween. Concrete that fills the space between the flange portion 21 without a gap is placed.
If this concrete is provided at least directly below the column base bracket 30 in the entire length of the H-shaped steel 20, the same effect as that of the reinforcing rib 24 described above can be exhibited. It can also be provided over the entire length of the steel plate 20 in the length direction. If it does in this way, the rigidity of the whole standing part 12 can be improved.

  Further, in this concrete placement, the reinforcing bar b connecting the upper flange portion 22 and the lower flange portion 21 is fixed to the H-shaped steel 20 by welding, so that the strength of the upright portion 12 can be further increased.

  Note that the reinforcing ribs 24 and the concrete cast on the side of the H-shaped steel 20 may be omitted if allowed by design. Moreover, the column part 1 is not limited to the hollow steel frame which forms a square cross section like the said embodiment, It can apply also to the steel column which comprises another shape, for example, a hollow steel frame with a circular cross section.

Moreover, in the said embodiment, although the cross-shaped structural member (the said board | plate material 33a, 33b) of the connection plate 33 was arrange | positioned so that it might face in the direction orthogonal to the length direction of the H-shaped steel 20, and its length direction, The direction of the leg bracket 30 is not limited to that embodiment, and for example, an embodiment in which the direction of each component is 45 degrees with respect to the length direction of the H-shaped steel 20 is also conceivable.
As long as a space for inserting the bolt 34 can be secured, such an embodiment can be adopted. As described above, when the lower plate 31 is welded to the upper flange portion 22, the bolt 34 can be used. Because there is no need to consider the space, it can be set in any orientation.

1 shows an embodiment, (a) is a front view, (b) a rear view, and (c) is a right side view of (a). Main part enlarged view of the same embodiment Perspective view of the same embodiment Main part exploded perspective view of the same embodiment Perspective view of conventional example Shows the basic structure of the building, (a) is an illustration of a solid foundation, (b) is an illustration of a single foundation (A) is a perspective view of a conventional example, (b) and (c) are reference diagrams assuming that a flanged column is fixed to a foundation made of H-shaped steel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pillar part 2 Flange 3, 22a, 31a Bolt hole 4 Anchor bolt 10 Base 11 Bottom plate part 12 Standing upper part 20 H-shaped steel 21 Lower flange part 22 Upper flange part 23 Web 24 Reinforcement rib 25 Connection board 26, 34 Bolt 30 Column base metal 31 Lower plate 32 Upper plate 33 Connection plate 33a, 33b Plate material

Claims (6)

H-shaped steel 20 comprising upper and lower flange portions 22 and 21 and a web 23 connecting the upper and lower flange portions 22 and 21 is placed on the bottom plate portion 11 of a solid foundation formed by placing concrete so that the upper flange portion 22 faces upward. In the column base structure of the building which is fixed so that the lower end of the vertical column 1 is fixed to the upper flange portion 22,
A column base 30 is interposed between the lower end of the column 1 and the upper flange 22, and the column base 30 is a horizontal upper plate 32 fixed to the lower end of the column 1; The lower plate 31 is fixed to the upper surface of the upper flange portion 22, and the connecting plate 33 has a cross shape in a plan view connecting the upper and lower plates 32, 31. The lower plate 31 and the upper flange portion 22 is a column base structure of a building, which is fixed through bolts 34 passing through the lower plate 31 and the upper flange portion 22 in the vertical direction.   The building column base structure according to claim 1, wherein the bolts (34) are arranged on both sides of the web (23).   The component member of the connecting plate 33 having a cross shape is a plate material in which the surface direction of the plate surface is arranged in the length direction and the width direction of the H-shaped steel 20, and the bolt 34 is connected to the connecting plate 33. The column base structure for a building according to claim 2, wherein the column base structure is provided in parallel with each other in the length direction and the width direction.   The building pillar according to any one of claims 1 to 3, wherein a reinforcing rib (24) connecting the upper flange portion (22) and the lower flange portion (21) is provided immediately below the column base metal fitting (30) of the H-shaped steel (20). Leg structure.   The column base structure for a building according to claim 4, wherein the reinforcing ribs 24 are directly below the connecting plate 33.   Immediately below the column base metal fitting 30 of the H-shaped steel 20, concrete is placed on at least one side across the web 23 so as to fill the space between the upper flange portion 22 and the lower flange portion 21 without any gap. A building column base structure according to any one of claims 1 to 5.

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