JP2021139149A - Base structure for steel frame structure - Google Patents

Abstract

To provide a base structure for a steel frame structure, where a base structure is to support columns of a frame structure provided with both of a rahmen frame structure and a brace frame structure, allowing mold frame work to be eliminated and downsizing of the base structure to be realized through installation in low cost in a period as short as possible.SOLUTION: A steel frame structure 100 is provided with: a plurality of steel rahmen frame structures 10 extending in a span direction; and a plurality of steel brace frame structures 20 extending in a direction of a ridge direction, wherein the plurality of rahmen frame structures 10 are installed with an interval in the ridge direction, respectively, and the brace frame structures 20 are formed with a plurality of columns 1 composing the rahmen frame structure 10, and beams 3 and braces 4 connecting the plurality of columns 1. A base structure 70 of a steel frame structure is configured to attach base plates 1c on a lower end of the column 1 and connect a reinforced-concrete base 40 and the base plates 1c through anchor bolts 8, respectively, wherein the base 40 is in a cylindrical shape and the base 40 and the base plates 1c are connected with pins in the span direction through axial force transmission members 60.SELECTED DRAWING: Figure 4

Description

The present invention relates to a basic structure of a steel frame.

There are various types of steel frames such as rigid frame frames made of steel and brace frames made of steel. Among them, in distribution facilities, warehouses, etc., a plurality of steel frame frames extending in the beam-to-beam direction are arranged at intervals in the girder direction, and adjacent rigid frame frames extend in the girder direction. A brace frame is formed by being connected by, and a frame having both a rigid frame frame and a brace frame is constructed. In this form of frame, the rigid frame frame and the brace frame share a pillar, and this pillar is supported by, for example, a reinforced concrete cloth foundation or an independent foundation. That is, the rigid frame frame and the brace frame also share the basics.

By the way, even when a horizontal force acts on the brace frame extending in the girder direction in the event of an earthquake or the like, the brace frame is hardly deformed, so that a bending moment is hardly generated in the column base or the foundation. On the other hand, if a horizontal force acts on the rigid frame frame extending in the inter-beam direction during an earthquake, the rigid frame frame will be displaced in the horizontal direction, and the foundation of the rigid frame frame will be structurally designed. By designing as a rigid frame, the foundation of the rigid frame frame needs to have a structure that can withstand the bending moment. Therefore, a foundation having a horizontally long rectangular footing in a plan view in a direction parallel to the structure surface of the rigid frame frame (inter-beam direction) is a rational foundation.

However, when constructing a reinforced concrete foundation having a rectangular parallelepiped footing and a rising portion erected from the footing in this way, formwork including assembling and removing the formwork is required, which requires a lot of labor. There is a problem such as this. As the scale of the building increases, the number of foundations (number of independent foundations) increases and the extension of foundations (extension of cloth foundations) becomes longer, and this problem becomes even more prominent.

In order to solve the problems of the formwork, a cylindrical foundation structure has been proposed that does not require the formwork and can reduce the construction work. Specifically, it is a foundation structure that supports the structure, and this foundation structure is integrated with a cylindrical outer frame formed of a thin steel plate and a cylindrical outer frame filled in the cylindrical outer frame. It is composed of concrete and a rust preventive material layer having a high rust preventive effect formed by coating or adhering to the outer surface of an outer frame made of a thin steel plate (see, for example, Patent Document 1).

On the other hand, in order to reduce the bending moment generated in the foundation, a construction method has been proposed in which the rotational rigidity of the column base is reduced by applying an elastic spring such as a countersunk spring to the column base. More specifically, regarding the method of joining the base plate, anchor bolt, and foundation reinforced concrete that make up the column base of the steel structure of the building, a specific spring constant is set between the base plate and the nut of the anchor bolt that fixes it. A column base joining method that inserts a spring member to have, and further inserts a spring member and an anchor bolt member having a specific spring constant between the base plate and the upper surface of the foundation reinforced concrete to make the rotational bending rigidity of the column flexible. (See, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2005-68951 Japanese Patent No. 3579211

By applying the foundation structure described in Patent Document 1, although the formwork can be eliminated, the length of the foundation of this plan view rectangle is replaced with the above-mentioned foundation having a horizontally long plan view rectangular footing in the inter-beam direction. If the foundation described in Patent Document 1 having a side as the diameter is applied, the foundation is unnecessarily long in the column direction, so that it cannot be said to be a rational foundation and is uneconomical.

On the other hand, by applying the column base joining method described in Patent Document 2, for example, the bending moment generated in the column base of the rigid frame frame can be reduced, and the size of the foundation can be reduced. The members are expensive, which leads to an increase in construction cost, and the provision of spring members does not make the joint between the column base and the foundation a perfect pin joint, for example, a semi-fixed joint, which improves the effect of reducing the bending moment. Leave room for.

The present invention has been made in view of the above problems, and the size of the foundation should be reduced by as inexpensive construction as possible with respect to the foundation structure for supporting the columns of the frame having both the rigid frame frame and the brace frame. The purpose is to provide the foundation structure of the steel frame that makes it possible.

In order to achieve the above object, one aspect of the basic structure of the steel frame according to the present invention is
A plurality of steel frame frames extending in the beam-to-beam direction and a plurality of steel frame braces extending in the girder direction are provided, and the plurality of rigid frame frames are arranged at intervals in the girder direction, and the braces are provided. The frame is a steel frame formed by a plurality of columns constituting the rigid frame frame and beams and braces connecting the plurality of columns. A base plate is attached to the lower end of the columns and is made of reinforced concrete. The foundation structure of the steel frame, in which the foundation of the frame and the base plate are connected via anchor bolts.
The foundation has a columnar shape
The foundation and the base plate are pin-joined in the inter-beam direction via an axial force transmitting member.

According to this aspect, in a so-called one-sided rigid frame frame / one-sided brace frame steel frame frame including a plurality of steel frame frames extending in the beam-to-beam direction and a plurality of steel frame brace frames extending in the girder direction, columns By pin-joining the base plate at the lower end and the foundation in the beam-to-beam direction (the structural surface direction of the rigid frame frame), it is possible to eliminate the bending moment in the column base and the foundation in which the bending moment in the beam-to-beam direction can be predominant. As a result, the dimension of the foundation in the inter-beam direction can be made as small as possible, and the overall dimension of the foundation defined by the dimension in the inter-beam direction can be matched with the dimension in the inter-beam direction. It is possible to form a foundation structure having a columnar foundation having as small a plane dimension as possible with the dimension of.

This pin joint is formed by an axial force transmitting member interposed between the foundation and the base plate. The axial force transmission member is literally a member whose purpose is to transmit the axial force from the column to the foundation, and the base plate mounted on the axial force transmission member has the axial force transmission member as a fulcrum between the beams. It is allowed to rotate left and right in the direction. By this action, the lower end of the column (the surface mounted on the axial force transmitting member) becomes free to rotate in the direction between the beams, and a pin joint (or a pin column base) is formed in this direction. In the girder direction in which the brace frame is formed, as described above, since the brace frame is hardly deformed by the acting horizontal force, the beam-to-beam direction of the foundation does not necessarily have to be pin-joined and is semi-fixed. It may be a joint or the like.

Further, in another aspect of the basic structure of the steel frame according to the present invention, both the axial force transmitting member and the anchor bolt are arranged at the center of the column formation in the inter-beam direction among the columns in a plan view. It is characterized by that.

According to this aspect, both the axial force transmitting member and the anchor bolt are connected to the foundation via the anchor bolt by being arranged at the center of the column formation in the inter-column direction of the columns in a plan view. The column (base plate) can be rotated left and right in the inter-beam direction with the axial force transmission member as a fulcrum, and a pin joint between the foundation and the base plate in the inter-beam direction can be formed. For example, in a form in which a column made of H-section steel is fixed to the foundation with the web arranged in the beam-to-beam direction, for example, two anchor bolts are at the center between the two flanges (the center of the web). Examples thereof include a form in which four anchor bolts are arranged on both sides of the web, and a form in which two anchor bolts are arranged on both sides of the web.

Further, in another aspect of the basic structure of the steel frame according to the present invention, the axial force transmitting member is composed of a solid and rectangular block body in a plan view, and the longitudinal direction of the rectangular view in a plan view is arranged toward the girder direction. Has been
The anchor bolt is characterized in that it penetrates the inside of the block body.

According to this aspect, the axial force transmitting member is formed of a solid block body having a rectangular shape in a plan view, and the longitudinal direction of the rectangular shape in a plan view is arranged toward the girder direction. While sufficiently transmitting the axial force from the column to the foundation, the column can be rotated in the direction between the beams, which is the lateral direction of the rectangular block body in a plan view. Here, the "planar view rectangle" includes a shape in which the plan view is rectangular, a shape in which the corner corners of the rectangle are chamfered in a curved manner, and a shape in which the plan view is a track shape. The plane dimensions of the axial force transmitting members are adjusted according to the axial force to be transmitted to the foundation, and the number of the axial force transmitting members may be a plurality as necessary. For example, axial force transmission members may be provided on the left and right sides of the web, and anchor bolts may penetrate through each axial force transmission member.

Further, in another aspect of the basic structure of the steel frame according to the present invention, the block body is a block body made of a cement-based material, a rectangular steel pipe having a rectangular frame in a plan view, and the inside of the square steel pipe is filled with a cement-based material. It is characterized by being composed of any one of a block body made of iron and a block body made of iron.

According to this aspect, the axial force from the column can be sufficiently transmitted to the foundation by the solid block body. In particular, in a rectangular steel pipe having a rectangular frame in a plan view and a block body in which a cement-based material is filled inside the square steel pipe, the square steel pipe plays the role of a formwork that does not require demolding, and the cement-based material is filled inside the square steel pipe. Therefore, the foundation structure can be constructed as inexpensively and efficiently as possible. Here, the "cement-based material" includes cement paste, mortar (including non-shrink mortar), and concrete.

Further, in another aspect of the basic structure of the steel frame according to the present invention, first elastic bodies are disposed on the sides of the two longitudinal side surfaces of the axial force transmitting member to support the base plate. And
The first elastic body is embedded in concrete.

According to this aspect, the first elastic body is arranged on the side of the two longitudinal side surfaces of the axial force transmitting member, and the first elastic body supports the base plate on the side of the axial force transmitting member. Therefore, when the column (and the base plate) rotates in the direction between the beams with the axial force transmitting member as the fulcrum, the first elastic body can absorb the displacement of the base plate while being deformed. Then, when the rotated base plate returns to the center of the axial force transmitting member, the first elastic body also expands and returns to the original state, so that the supporting posture of the base plate can be maintained. Here, the "first elastic body" can be formed of, for example, a rectangular parallelepiped standard foamable resin or the like. Further, for example, since the first elastic body is completely embedded in concrete, the first elastic body can be surrounded by the foundation, the base plate, and concrete without exposing the first elastic body to the outside. Here, in "concrete", soil concrete (including a form in which reinforcing bars for preventing cracks are embedded), concrete forming a structural slab (reinforced concrete), concrete forming a foundation beam (reinforced concrete), and a foundation pillar are formed. Includes concrete (reinforced concrete), etc.

Further, in another aspect of the basic structure of the steel frame according to the present invention, first elastic bodies are disposed on the sides of the two longitudinal side surfaces of the axial force transmitting member to support the base plate. And
The circumference of the column is surrounded by a second elastic body having a height extending from the top of the foundation to a certain level of the column base of the column.
The second elastic body is embedded in concrete.

According to this aspect, when concrete is cast to the middle level of the column base, the height extending from the top of the foundation to a certain level of the column base (for example, a height of about 30 cm to 50 cm above the base plate). Since the circumference of the column is surrounded by the two elastic bodies, the displacement of the column base can be absorbed by the second elastic body while the column base and the soil concrete are trimmed by the second elastic body. In addition, here as well, "concrete" includes various forms of concrete, including the above-mentioned soil concrete.

Further, in another aspect of the foundation structure of the steel frame according to the present invention, the foundation is composed of a cylinder formed of a thin steel plate and a cylinder made of reinforced concrete inside the cylinder. It is a feature.

According to this aspect, the foundation has a cylinder formed of a thin steel plate and a cylinder made of reinforced concrete inside the cylinder, so that the inside of the cylinder is filled with concrete and the cylinder is viewed from the inside. When a concrete pressure is applied, a tensile force in the circumferential direction acts on a cylindrical body made of a cylindrical steel plate having a strong tensile force to resist the concrete pressure. Therefore, the cylindrical body is formed of a thin steel plate. Will be possible. Furthermore, the cylindrical body can be constructed while using the cylindrical body made of thin steel plate as the formwork, and by not removing the cylindrical body, the formwork can be eliminated and the workability of the basic structure can be improved. Connect.

As can be understood from the above explanation, according to the basic structure of the steel frame of the present invention, the foundation structure for supporting the columns of the frame having both the rigid frame frame and the brace frame can be constructed at the lowest possible cost. The size of the foundation can be reduced.

It is a perspective view which shows an example of the steel frame frame provided with the foundation structure which concerns on embodiment. It is a perspective view which shows the foundation structure which concerns on embodiment together with the soil concrete. It is a perspective view which shows the basic structure which concerns on embodiment. It is a perspective view which shows the state which removed the 2nd elastic body from the foundation structure shown in FIG. It is a perspective view which shows only an example of an axial force transmission member and an anchor bolt. It is a view of the arrow in the VI direction of FIG. It is a VII direction arrow view of FIG. It is the VIII direction arrow view of FIG. It is the figure corresponding to FIG. 6, and is the figure which shows another example of the foundation structure.

Hereinafter, the basic structure of the steel frame according to the embodiment will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Basic structure of steel frame according to the embodiment]
<Steel frame>
First, an example of a steel frame frame provided with a foundation structure according to an embodiment will be described with reference to FIG. Here, FIG. 1 is a perspective view showing an example of a steel frame frame provided with a foundation structure according to an embodiment.

The steel frame frame 100 is applied as, for example, a one-story distribution facility, a warehouse, a factory, a plant facility, an office, etc., and various types are formed by attaching a wall material or a roof material to the steel frame frame 100 shown in FIG. A one-story building is constructed. The steel frame frame 100 has a plurality of steel frame ramen frames 10 extending in the beam-to-beam direction and a plurality of steel frame brace frames 20 extending in the girder direction. The plurality of ramen frames 10 are arranged at predetermined intervals in the column direction.

The ramen frame 10 in the illustrated example presents a gate-shaped frame having three columns 1 and a beam 2 connecting the stigmas of adjacent columns 1, and the columns 1 and 2 are bolted together with high-strength bolts or the like. It is rigidly joined by welding. The rigid frame frame may be a gate-shaped frame having two pillars 1 and a wide opening.

On the other hand, in the brace frame 20, the pillar 1 constituting the rigid frame frame 10, the stigma and pedestal of the adjacent pillar 1, the horizontal furring strip 3 (beam) connecting the middle stage of the pillar, and the adjacent pillar 1 and the upper and lower horizontal barrels It is formed by a brace 4 bridged in a manner intersecting the diagonal lines of a rectangular frame formed by the edge 3. Further, in the brace frame 20 of the illustrated example, the vertical furring strip 5 is arranged between the adjacent columns 1. Although the brace frames 20 in the illustrated example are arranged at intervals in the girder direction, the brace frames 20 may be continuous in the girder direction, and the brace 4 may intersect in the girder direction. In addition, the form may be arranged only on one diagonal line.

The columns 1 and beams 2 in the illustrated example are formed of H-shaped steel, and the horizontal furring strip 3 and the vertical furring strip 5 are formed of channel steel. Further, the brace 4 in the illustrated example is formed of a steel rod provided with a turnbuckle. The columns 1 and beams 2 may be formed of other shaped steel materials, square steel pipes, or the like, and the braces 4 may be formed of flat steel or the like.

In the steel frame frame 100 composed of the plurality of rigid frame frames 10 and the brace frame 20, a plurality of horizontal furring strips 3 extending in the girder direction are arranged above the beams 2 constituting each rigid frame frame 10 and intersect with each other. It further has a roof frame provided with a plurality of sets of braces 4 to be bridged in a mode.

The column base of the column 1 constituting the steel frame frame 100 is fixed to the foundation structure described in detail below, and the lower portion of the column base is embedded in the soil concrete 30 (an example of concrete). It should be noted that, in general, reinforcing bars for preventing cracks are embedded in the soil concrete 30. Further, the concrete in which the lower part of the column base is buried may be reinforced concrete forming a structural slab, reinforced concrete forming a foundation beam, reinforced concrete forming a foundation column, or the like, in addition to soil concrete.

In the foundation structure of the column base of the column 1 of the steel frame frame 100 in the illustrated example, the foundation and the column 1 are provided so that a bending moment in the inter-beam direction is not generated when a horizontal force in the inter-beam direction acts on the column 1. It is pin-joined in the direction between the beams. On the other hand, when the horizontal force in the girder direction acts on the column 1, the brace frame 20 is hardly deformed, so that the bending moment in the girder direction is small even if it is generated in the foundation structure of the column base of the column 1. Therefore, in the foundation structure of the column base of the column 1, the girder direction of the column 1 and the column 1 may be a semi-fixed joint (the rotation of the column 1 with respect to the foundation is restricted to some extent), and may not necessarily be a pin joint.

<Basic structure>
Next, an example of the basic structure according to the embodiment will be described with reference to FIGS. 2 to 8. Here, FIG. 2 is a perspective view showing the foundation structure according to the embodiment together with the soil concrete. 3 is a perspective view showing the basic structure according to the embodiment, FIG. 4 is a perspective view showing a state in which the second elastic body is removed from the basic structure shown in FIG. 3, and FIG. 5 is a shaft. It is a perspective view which shows only an example of a force transmission member and an anchor bolt. Further, FIGS. 6 to 8 are an arrow view in the VI direction, an arrow view in the VII direction, and an arrow view in the VIII direction of FIG. 3, respectively. In addition, in FIGS. 2 to 4 and 6 to 8, the column 1 is cut at an intermediate position, and only the column base is shown.

As shown in FIG. 4, the foundation structure 70 includes a foundation 40, an axial force transmitting member 60 and a first elastic body 50A mounted on the upper surface of the foundation 40, and an axial force transmitting member 60 and a first elastic body 50A. It has a base plate 1c at the lower end of the pillar 1 mounted on the base plate 1 and an anchor bolt 8 for connecting the base plate 1c and the foundation 40 via an axial force transmitting member 60.

With respect to the configuration shown in FIG. 4, as shown in FIG. 3, the second elastic body 50B surrounds the axial force transmitting member 60, the first elastic body 50A, the base plate 1c, and the column base of the column 1 up to a certain level. By doing so, the basic structure 70 is formed. As shown in FIG. 2, the foundation structure 70 is embedded in the soil concrete 30 from the top end of the foundation 40 to the upper end of the second elastic body 50B, for example, so that the foundation structure 70 has the soil concrete 30 and the second elastic body 50B. It is integrally formed in a manner cut off by. In addition, in FIGS. 2 and 3 and the like, the second elastic body 50B surrounds the column base of the column 1 made of H-shaped steel in a rectangular tubular shape, but the second elastic body 50B is the column 1. The second elastic body 50B surrounds the column base of the column 1 in a manner in which the second elastic body 50B surrounds the column base of the column 1 in such a manner that it is arranged so as to be applied to the outer peripheral surface of the web or flange of the H-shaped steel forming the above. There may be. Further, in this form, the second elastic body 50B may be arranged without a gap on the outer peripheral surface of the stiffener 1e shown in FIGS. 3 and 4 and the like.

As shown in detail in FIG. 5, the axial force transmitting member 60 has a rectangular steel pipe 61 having a rectangular frame in a plan view, and a cement block 62 formed by filling and hardening a cement-based material inside the square steel pipe 61. It is a solid block body. As the cement-based material, for example, non-shrink mortar or the like is applied. The square steel pipe 61 also includes a form in which four flat steel pieces are welded and joined in a rectangular frame shape in a plan view.

On the other hand, the first elastic body 50A is a rectangular parallelepiped elastic body, and is preferably formed of a foamable resin or the like having a certain degree of rigidity and elasticity. For example, a foamable resin containing polystyrene as a main component can be applied. Further, the second elastic body 50B is a plate-shaped elastic body, and can be formed of the same material as the first elastic body 50A.

The axial force transmission member 60 is literally a member that transmits the axial force from the column 1 to the foundation 40. Since the foundation structure 70 is designed so that a bending moment does not occur in the beam-to-beam direction, the axial force transmitting member 60 having the flat area A1 should have a function of transmitting the axial force from the column 1 to the foundation 40. Just do it. The axial force transmitting member 60 shown in the drawing has a rectangular shape in a plan view (more specifically, a shape in which a corner portion is R-processed), but may have a track shape in a plan view, for example.

Since the foundation structure 70 of the illustrated example has two anchor bolts 8 as shown in FIG. 4, for example, the two anchor bolts 8 are the axial force transmitting members 60 located below the center of the base plate 1c. It penetrates the cement-based block 62.

In addition to the form shown in the illustrated example, the axial force transmitting member 60 may be a block body made of only a cement-based material or a block body made of iron. However, in the axial force transmission member 60 of the illustrated example, since the cement-based material is filled inside the square steel pipe 61 and the square steel pipe 61 is left behind, the square steel pipe 61 also functions as a formwork and can be removed from the mold. It has excellent workability because it can be made unnecessary. Further, since the material cost and the construction cost (manufacturing cost) are lower than those of the solid iron block body having the same flat area, the axial force transmission member 60 of the illustrated example is suitable.

As shown in FIG. 4, the pillar 1 made of H-shaped steel is arranged so that the pillar 1 faces the strong axis direction on the structural surface of the rigid frame frame 10. Therefore, of the columns 1, the web 1a is oriented in the beam-to-beam direction, and the two flanges 1b are oriented in the girder direction. A steel base plate 1c is welded to the lower end of the column 1, and at the center position of the base plate 1c (the center position of the web 1a), the axial force transmitting member 60 having a rectangular shape in a plan view has its longitudinal direction in the girder direction. It is arranged in a facing posture. A first elastic body 50A is arranged on each side of the left and right longitudinal side surfaces of the axial force transmitting member 60, and the base plate 1c is supported by the two first elastic bodies 50A and the axial force transmitting member 60. doing. In the column base, a steel two-stage stiffener 1e is joined to the web 1a and the two flanges 1b by welding to stiffen the column base, and the stiffener 1e is, for example, an underground beam ( (Not shown) are welded together.

Bolt holes in the base plate 1c at the center position of the web 1a (the intermediate position between the two flanges 1b and the center t / 2 of the width t of the web 1a) at the same distance to the left and right from the web 1a. (Not shown) is opened, and the anchor bolt 8 penetrates the cement-based block 62 through the corresponding bolt hole and is anchored to the lower foundation 40. Here, in the illustrated example, one anchor bolt 8 is arranged on each of the left and right sides of the web 1a, but a plurality of anchor bolts 8 are arranged on each of the left and right sides of the web 1a as necessary for design. Even in this case, each anchor bolt is arranged at the center position of the web 1a.

Since the base plate 1c is supported by the axial force transmitting member 60 that is long in the girder direction at its central position, when a horizontal force acts on the column 1 in the beam-to-beam direction as shown in FIG. 4, the column 1 ( The base plate 1c) is allowed to rotate in the X direction, which is the inter-beam direction, so that the base plate 1c and the foundation 40 are pin-joined in the inter-beam direction (pin column base).

Further, since the first elastic body 50A is arranged on the side surface of the axial force transmission member 60 in the longitudinal direction, the base plate 1c rotates in one direction and the first elastic body 50A in the rotation direction thereof. When the first elastic body 50A is compressed, the first elastic body 50A is compressed and deformed, and when the base plate 1c rotates to the other side and returns, the first elastic body 50A in the compressed state expands and returns to the original state. , The first elastic body 50A is always in close contact with the base plate 1c to maintain a supporting posture.

On the other hand, as is clear from FIG. 4, the axial force transmitting member 60 is long in the girder direction, and the two anchor bolts 8 are arranged at positions separated from the web 1a in the girder direction. The foundation 40 and the base plate 1c are not pin-bonded but semi-fixed joints (joints with a certain degree of fixation). However, as described above, since the brace frame 20 is hardly deformed in the girder direction, the bending moment in the girder direction is hardly generated in the foundation 40 and the base plate 1c.

As described above, in the foundation 40, since the bending moment is not generated in the beam-to-beam direction and the bending moment generated in the girder direction is small, the plane dimension of the foundation 40 can be set to the smallest possible dimension. If a bending moment in the inter-beam direction is generated in the foundation structure of the column base of the column 1, considering that almost no bending moment is generated in the girder direction, the bending moment in the inter-beam direction can be resisted in the inter-beam direction. It is necessary to construct a rectangular foundation with a horizontally long footing. In this construction, when the foundation is constructed with reinforced concrete, formwork (installation and removal of the formwork) is required, and it takes time to construct the foundation.

The foundation 40 of the illustrated example has a cylindrical body 41 formed of a thin steel plate and a cylindrical body 42 made of reinforced concrete inside the cylindrical body 41. When concrete is filled inside the cylindrical body 41 and concrete pressure is applied to the cylindrical body 41 from the inside, a tensile force in the circumferential direction acts on the cylindrical body 41 made of a cylindrical and strong steel plate. Since it can withstand the concrete pressure, the cylindrical body 41 can be formed of a thin steel plate.

Further, a cylindrical body 42 made of reinforced concrete can be constructed while using a cylindrical body 41 made of a thin steel plate as a formwork, and further, by not removing the cylindrical body 41, the formwork work can be eliminated and the basic structure can be constructed. It leads to improvement of workability of 70.

Further, as shown in FIGS. 2 and 6 to 8, soil concrete 30 is constructed around the axial force transmitting member 60, the first elastic body 50A, the base plate 1c, and the second elastic body 50B. As a result, the foundation structure 70 and the soil concrete 30 are completely cut off by the second elastic body 50B, and the displacement of the column base is absorbed by the second elastic body 50B, so that the soil concrete 30 caused by the displacement of the column base The occurrence of cracks can be eliminated. In the illustrated example, a plurality of plate-shaped second elastic bodies 50B having a thickness of 25 mm or more surround the four sides of the base plate 1c and the like, and surround the four sides of the column base above the base plate 1c and the like. Here, for the square steel pipe 61 forming the axial force transmission member 60, for example, a steel pipe having a plane dimension of about 200 mm × 100 mm and a thickness of about 5 mm can be applied.

As shown in FIGS. 6 to 8, a filling mortar 1f is constructed up to the top level of the soil concrete 30 in the space above the upper stiffener 1e, and the upper end of the second elastic body 50B and the flange 1b of the column 1 are installed. A seal of modified silicone or the like is installed between them. Further, a non-shrink mortar may be filled between the square steel pipe 61 and the first elastic body 50A on the side thereof.

According to the illustrated foundation structure 70, with respect to the foundation structure that supports the pillar 1 of the steel frame frame 100 having both the rigid frame frame 10 and the brace frame 20, the formwork can be eliminated and the cost is as low as possible. The size of the foundation 40 can be reduced by various constructions.

Further, FIG. 9 is a diagram corresponding to FIG. 6 and is a diagram showing another example of the basic structure. In the foundation structure 70A shown in FIG. 9, in order to transmit the axial force from the column 1 to the foundation 40, a unique axial force transmitting member 60 is provided for each anchor bolt 8, and the flat area A1-2 of each axial force transmitting member 60 is provided. It is a foundation structure having an axial force transmitting member having a double flat area A2. In this way, by increasing the number of the axial force transmitting members 60 according to the axial force acting on the pillar 1 or increasing the flat area of the axial force transmitting member 60, the axial force acting on the pillar 1 is based on 40. It becomes possible to sufficiently convey to. In the foundation structure 70A, the first elastic bodies arranged on the sides of the two axial force transmitting members 60 may have the left and right plane dimensions of the base plate 1c.

Other embodiments may be obtained in which other components are combined with respect to the configurations listed in the above embodiments, and the present invention is not limited to the configurations shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

1: Pillar 1a: Web 1b: Flange 1c: Base plate 1e: Stifuna 1f: Filled mortar 1g: Seal 2: Beam 3: Beam (horizontal furring strip)
4: Brace 5: Vertical furring strip 8: Anchor bolt 10: Rahmen frame 20: Brace frame 30: Soil concrete (concrete)
40: Foundation 41: Cylindrical body 42: Cylindrical body 50A: First elastic body 50B: Second elastic body 60: Axial force transmission member 61: Square steel pipe 62: Cement-based block 70, 70A: Foundation structure (foundation structure of steel frame) )
100: Steel frame

Claims (7)

A plurality of steel frame frames extending in the beam-to-beam direction and a plurality of steel frame braces extending in the girder direction are provided, and the plurality of rigid frame frames are arranged at intervals in the girder direction, and the braces are provided. The frame is a steel frame formed by a plurality of columns constituting the rigid frame frame and beams and braces connecting the plurality of columns. A base plate is attached to the lower end of the columns and is made of reinforced concrete. The foundation structure of the steel frame, in which the foundation of the frame and the base plate are connected via anchor bolts.
The foundation has a columnar shape
A foundation structure of a steel frame, wherein the foundation and the base plate are pin-joined in a beam-to-beam direction via an axial force transmission member. The foundation of the steel frame frame according to claim 1, wherein both the axial force transmitting member and the anchor bolt are arranged at the center of the column formation in the inter-beam direction among the columns in a plan view. structure. The axial force transmitting member is composed of a solid block body having a rectangular shape in a plan view, and is arranged such that the longitudinal direction of the rectangular shape in a plan view is directed to the girder direction.
The basic structure of a steel frame according to claim 1 or 2, wherein the anchor bolt penetrates the inside of the block body. The block body is composed of any one of a block body made of a cement-based material, a rectangular steel pipe having a rectangular frame in a plan view, a block body in which the cement-based material is filled inside the square steel pipe, and an iron block body. 3. The basic structure of the steel frame frame according to claim 3. A first elastic body is disposed on each side of the two longitudinal side surfaces of the axial force transmitting member to support the base plate.
The basic structure of a steel frame according to claim 3 or 4, wherein the first elastic body is embedded in concrete. A first elastic body is disposed on each side of the two longitudinal side surfaces of the axial force transmitting member to support the base plate.
The circumference of the column is surrounded by a second elastic body having a height extending from the top of the foundation to a certain level of the column base of the column.
The basic structure of a steel frame according to claim 3 or 4, wherein the second elastic body is embedded in concrete. The foundation according to any one of claims 1 to 6, wherein the foundation is composed of a cylinder formed of a thin steel plate and a cylinder made of reinforced concrete inside the cylinder. The basic structure of the steel frame.

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