JP3244161B2 - Steel column base using reinforced wire mesh - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel column base when a steel structure is used for civil engineering, construction or a work.

[0002]

2. Description of the Related Art When a steel column is to be erected on a reinforced concrete foundation, a plurality of anchor bolts 2 are buried in the foundation concrete 1 in advance as shown in FIGS.
A column 4 having a base plate 5 with a bolt hole 6 formed in a predetermined position so as to be fitted to the anchor bolt 2 is erected, and the base plate 5 and the anchor bolt 2 are tightened with a nut 7 to fix the column base and the foundation concrete. Join. A fixing metal 3 is attached to a lower end of the anchor bolt 2, and a foundation rising reinforcement 8 and a hoop reinforcement 9 are embedded in the foundation concrete 1.

In a conventional column base, a compressive force is transmitted to a foundation via a base plate, an anchor bolt bears a tensile force generated by a bending moment applied to the column base, and a shearing force is generated by a frictional force between the lower surface of the base plate and the foundation. The design is based on what is transmitted.

In order to install this column base, a base plate fixed under a column by welding or the like in a factory or the like is fitted to an anchor bolt already buried in foundation concrete. It is necessary to secure. Anchor bolts are installed prior to foundation concrete placement.Temporary support structures are provided to prevent the bolts from moving due to the impact of concrete placement. Then, a bolt hole is made, the bolt hole is fitted to the top of the bolt, the anchor bolt is bound with a template, and concrete is poured. This template is usually removed after casting concrete, and mortar or the like is applied thereon to a predetermined height and hardened. These bolt positioning means are all temporary and are designed not to contribute to the design strength.

[0005]

By the way, since the column base supports the weight of the building, a large compressive force acts on the lower surface of the base plate. When the compressive force is increased, the base concrete cannot withstand the compressive force, and a stress is generated that splits in a direction perpendicular to the compression direction (horizontal direction), and a force acts to cause a crack in the vertical direction. Therefore, as a design means, a method of enlarging the base plate and enlarging the cross section of the foundation concrete to prevent cracking is generally performed.

When a horizontal force such as seismic force or wind pressure is applied to a building, a shear force acts on the column base together with a bending moment. The bearing reaction force on the lower surface of the base due to the bending moment is deviated, and the shearing force is transmitted to the foundation by the frictional force of this portion. Therefore, the shearing force is not uniformly distributed on the cross section of the foundation, so that one side of the foundation is scraped and broken. When the bending moment and the shearing force are further increased, the shearing force is not transmitted by the frictional force, and the shearing force is transmitted to the bolt shaft, and the bolt shaft applies a horizontal supporting force to the concrete, and the thickness of the bolt is reduced. This will cause local destruction of the foundation concrete on the smaller side. This is because these crushing failures and local ruptures do not allow the shearing force to be distributed to the base section. For that purpose, it is necessary to design the base section to be large.

Now, when a bending moment is applied to the column base,
A tensile force is applied to the anchor bolt. Ultimately, concrete breaks in a cone shape with the anchoring end of the anchor bolt tip as the top. This drag is the fixing resistance. In order to increase the fixing resistance, the length of the anchor bolt must be increased in order to increase the broken shape of the cone.

In order to maintain the positional accuracy so that the anchor bolt is not moved by casting concrete, a temporary support structure must be provided to fix the anchor bolt. In particular, the horizontal movement of the anchor bolt not only makes it impossible to fit the base plate, but also makes it impossible to secure the accuracy of the upper steel frame. If the error is large, the concrete at the top of the anchor bolt is scraped off and straightened by heating using a gas burner or the like, but there is still a problem in proof stress.
For this purpose, a method of securing the mutual positions of the tops of the anchor bolts using a template or the like is used, but this is not only a hindrance to concrete placing work but also a material to be removed when finishing mortar, which is unnecessary in design. Material.

As an anchor bolt, it is known that a U-shaped anchor bolt obtained by bending a steel bar is mechanically efficient. This anchor bolt is often cold-worked into a U-shape. In this case, residual stress remains in the bent portion, and the U-shaped top tends to spread due to the impact of the transport or installation of the bolt. It is difficult to predict its size, it will not fit with the base plate, and the U-shaped bolt is excellent, but has a problem in precision control.

The present invention solves the above-mentioned various problems in the prior art, and can simultaneously achieve reinforcement of the foundation concrete portion of the column base and maintenance of the positional accuracy of the anchor bolts with a relatively simple structure. It is intended to provide a column base structure.

[0011]

According to the present invention, an anchor bolt is buried in a foundation concrete, and a column having a base plate having a bolt hole at a predetermined position so as to be fitted to the anchor bolt is erected. In a steel column base that stands on a steel column on a foundation by fixing the anchor bolt and the base plate with a nut, a steel rod is assembled in a mesh shape, and a sheet-like wire netting with the intersection thereof fixed is horizontally positioned above the anchor bolt. The anchor bolt is buried in the foundation concrete, and a space where meshes intersect is defined as a predetermined position of the anchor bolt, and a bolt shaft portion is inserted through the gap. The anchor bolt is a U-shaped anchor bolt, and the U-shaped anchor bolt is provided. To keep the top of the
A mesh wire mesh directly connecting the opposing bolt shafts and another mesh wire mesh are multi-tiered.

Further, according to the present invention, an anchor bolt is buried in a foundation concrete, and a column having a base plate having a bolt hole at a predetermined position is set up so as to fit the anchor bolt. In a steel column base on which a steel column is erected on a foundation by fixing a base plate with a nut, a steel rod is assembled in a mesh shape, and a sheet-like wire netting fixed at the intersection thereof is made horizontal so that the base concrete on the anchor bolt is located above the anchor bolt. A support structure such as a shaped steel or the like in which a bolt shaft portion is inserted into the gap with the gap where the mesh intersects as a predetermined position of the anchor bolt, and the sheet-shaped wire mesh is erected outside the anchor bolt. It is fixed to.

Further, according to the present invention, an anchor bolt is buried in a foundation concrete, and a column having a base plate having a bolt hole at a predetermined position is fitted to the anchor bolt, and the anchor bolt and the base plate are erected. In a steel column base on which a steel column is erected on the foundation by fixing with a nut, a steel rod is assembled in a mesh shape, and a sheet-like wire mesh with its intersection fixed is made horizontal to the base concrete on the anchor bolts. A buried, mesh-intersecting gap is defined as a predetermined position of the anchor bolt, a bolt shaft is inserted into the gap, and the outer periphery of the sheet-like wire mesh is arranged around the foundation concrete, and the outside of the rising vertical streak and the hoop. It is bent down to form a part of the basket-shaped reinforcing bars.

[0014]

[0015]

[0016]

[0017]

[0018]

As described above, the conventional pillar base has a standing outer peripheral portion reinforced with a reinforcing bar, and a straight portion immediately below the base plate is in a straight state. For this reason, there is a risk of local destruction due to shearing force, uneven distribution stress on the base plate at the time of bending moment, and the like. In addition, splitting stress due to direct pressure and concrete destruction due to ultimate anchoring strength of anchor bolts,
A method of reducing these stresses by enlarging the base plate and the base section itself has been adopted.

Looking at these fracture patterns, there is a tendency to pass through the horizontal section of concrete, so that the sheet-shaped wire mesh according to the present invention is horizontally arranged.
It is an effective reinforcement method from the viewpoint of concrete fracture characteristics.

Further, the sheet-like wire mesh according to the present invention comprises:
Since it has the property of dispersing the stress causing fracture, it has the effect of expanding the load-bearing cross section of the foundation. Each intersection of the sheet-like wire mesh is fixed by welding or the like, so that it can be integrated with concrete.

Further, since the mesh-like intersection of the sheet-like wire net is fixed by welding or the like, the positions of the bolts are fixed, and the positional accuracy of the anchor bolts is secured. If the vertical members of the lower support structure are extended using the support structure below the anchor bolts and the outer periphery of the upper sheet or the multi-stage sheet, or if the vertical members are assembled into cages using reinforcing steel, the conventional steel It is simpler than a supporting structure and can also serve as reinforcement for concrete.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show the basic shape of a sheet-like wire mesh, in which steel rods 11 are assembled in a mesh shape, and their intersections are fixed by welding binding wires, an adhesive, or a combination of both, and the like. The gap 12 is located at a predetermined position of the anchor bolt so that the bolt 2 can be inserted. FIG. 2 shows a ladder-shaped mesh wire mesh which is suitable for use in positioning a set of U-shaped anchor bolts in a U-shaped bottom side parallel to each other in a task-like manner. In addition, the above-mentioned sheet-shaped wire netting may use expanded metal formed in a mesh shape.

FIGS. 3 and 4 show sheet-like wire meshes 10A and 10A.
0B, the steel rod 11 is also arranged on the outer periphery of the bolt 2.
Each of them is responsible for positioning the bolt, dispersing the shearing force applied to the bolt, and reinforcing the shear of the concrete. FIG.
In addition, the sheet-like wire meshes 10A and 10B of FIG.

FIGS. 5 and 6 show a square steel bar 11A as a steel bar.
The intersection is fixed by, for example, welding 13. The rectangular gap 12 has such a size that the bolt 2 is inscribed. 7 and 8 show a round bar 11B as a steel bar.
Is used.

FIGS. 9 and 10 show a steel plate 14 fixed to a rectangular gap portion by welding 13 or the like and a bolt hole 15 formed in the steel plate 14 in order to increase the positional accuracy of the bolt.

FIGS. 11 to 14 show various usages of the above-described sheet-like wire mesh. FIG. 11 shows a basic form. The sheet-like wire mesh 10 is buried in the foundation concrete 1 above the anchor bolt 2 near the base plate 5. Things.
This sheet-like wire mesh 10 is used for positioning anchor bolts,
Disperses the shearing force applied to the bolts and prevents local destruction due to bearing pressure and shearing force for concrete reinforcement.

FIG. 12 shows a sheet metal mesh 10 arranged at an intermediate portion in addition to an upper sheet metal mesh, which is useful for preventing splitting due to direct pressure. FIG. 13 shows a sheet metal net 10 arranged at the lower portion, which is useful for reinforcing the fixing portion at the lower end of the anchor bolt 2.

FIG. 14 shows a U-shaped anchor bolt 2A used as an anchor bolt. In order to prevent the top portion of the bolt from opening, the sheet-like wire mesh 10B shown in FIG. 4 and the sheet-like wire mesh 10A shown in FIG. It will be a multi-stage stack used together.

Regardless of which type of anchor bolt is used, the number of steps of the sheet-like wire net is one or more steps depending on the stress of the column base and the sectional shape of the foundation, and embedded in concrete.

FIGS. 15 and 16 show a sheet-like metal net extended to the outside of the anchor bolt and fixed to the bolt support structure. That is, the section steel 16 and the like are erected outside the anchor bolt 2, the sheet-like wire mesh 10 is arranged in the upper stage, the lower stage, and in the middle as necessary, and the outer periphery of the sheet-like
, And the anchor bolt 2 is inserted into a predetermined position.
The lowermost stage is fastened by the nut 7 with the fixing hardware 17 interposed therebetween for fixing the anchor bolt 2.

The shape steel 16 as the vertical member and the sheet metal mesh 10 are fixed by welding or, as shown in FIGS. 17 and 18, a plate 18 as an attachment metal is attached to an outer corner of the sheet metal mesh 10. Alternatively, the angle 19 is welded, and the mounting hardware 18, 19 and the shaped steel 16 are tightened with bolts 20.

FIGS. 19 and 20 show an anchor bolt having a bent tip or a U-shaped anchor bolt 2.
Using A, the outer periphery of the sheet-like wire mesh 10 is bent down to the outside of the upright vertical bars 8 and the hoops 9 arranged around the foundation concrete, thereby forming a part of the basket-like basic reinforcement.

[0034]

The present invention has the following excellent effects. (1) It is an effective means for preventing splitting due to direct pressure, and is effective as an alternative to enlarging the base plate and the foundation concrete. (2) The shear force of the concrete can be increased, and the shear force applied to the bolt shaft can be distributed to the bolt group. Thereby, the local shearing force is distributed, and the basic shearing surface works effectively. (3) Since the anchoring force of the anchor bolt increases, the anchoring length of the bolt can be reduced, and the concrete can be prevented from cracking. (4) The position accuracy of the anchor bolt can be secured. While the conventional template is a temporary material, the present invention simultaneously satisfies the construction problem of maintaining accuracy and the reinforcement of concrete.

(5) If a ladder-shaped sheet metal mesh is attached to the U-shaped anchor bolt at the time of factory shipment, the ladder-shaped sheet metal mesh will have the above-mentioned mechanical effect. (6) If the anchor bolts are installed by using the sheet-like wire mesh of the present invention, it is simpler than the conventional steel support structure, and the cost is reduced. (7) Construction accuracy is improved by the present invention, and safety of a structure is easily ensured by a mechanical effect.

[Brief description of the drawings]

FIG. 1 is a plan view showing a basic form of a mesh wire mesh as a reinforcing wire mesh.

FIG. 2 is a plan view showing a basic form of a ladder-like sheet wire mesh as a reinforcing wire mesh.

FIG. 3 is a plan view showing the entire sheet-like wire mesh.

FIG. 4 is a plan view showing the entire ladder-like sheet wire mesh.

FIG. 5 is a detailed plan view of a sheet-like wire mesh using a square steel bar as the steel bar.

FIG. 6 is a front view of FIG. 5;

FIG. 7 is a detailed plan view of a sheet-like wire mesh using round steel as a steel rod.

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a detailed plan view of a sheet-like wire mesh in which a steel plate having a bolt hole is welded to a rectangular gap.

FIG. 10 is a front view of FIG. 9;

FIG. 11 is a longitudinal sectional view of a steel column base using a sheet-like wire mesh as a reinforcing wire mesh.

FIG. 12 is a longitudinal sectional view of a steel column base in which a sheet-like wire mesh is embedded in an intermediate portion together with an upper portion of an anchor bolt.

FIG. 13 is a longitudinal sectional view of a steel column base in which a sheet-like wire mesh is buried in the lower part together with the upper part of the anchor bolt.

FIG. 14 is a longitudinal sectional view of a steel column base in which a U-shaped anchor bolt is used as an anchor bolt and a sheet-like wire mesh is buried in the upper and lower portions thereof.

FIG. 15 is a front view in which the sheet-like wire mesh is extended to the outside of the anchor bolt and fixed to the support structure.

FIG. 16 is a sectional view taken along line AA of FIG. 15;

FIG. 17 is a plan view showing an aspect in which the sheet-like wire mesh is fixed to the support structure.

FIG. 18 is a plan view showing another example.

FIG. 19 is a front view in which the sheet-like wire mesh is bent down to the outside of the vertical streaks and the hoop to be a part of the basic bar arrangement.

FIG. 20 is a sectional view taken along line AA of FIG. 19;

FIG. 21 is a longitudinal sectional view of a conventional steel column base.

FIG. 22 is a plan view of FIG. 21;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reinforced concrete foundation 2 ... Anchor bolt 3 ... Fixing hardware 4 ... Steel column 5 ... Base plate 6 ... Bolt hole 7 ... Nut 8 ... Rising steel 9 ... Hoop 10 ... Sheet wire mesh 11 ... Steel rod 13 ... Welding 14 ... Steel plate 15 ... Bolt hole 16 ... Shape steel 17 ... Fixed hardware 18 ... Plate 19 ...・ Angle 20 ・ ・ ・ Bolt

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kuniaki Sato 24-21 Yaesaki-cho, Hiratsuka-shi, Kanagawa (72) Inventor Toshio Saeki 6-15-7-502, Tsurumaki, Tama-shi, Tokyo (72) Invention Person Mitsunobu Iwata No.4-2-2 Toyo, Koto-ku, Tokyo Inside Hitachi Koki Co., Ltd. (72) Inventor Shigeru Hirakawa 1-9-1 Kitahama, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Hitachi Metals Co., Ltd. (56 References JP-A-7-324338 (JP, A) JP-A-57-117108 (JP, U) JP-A-62-143755 (JP, U) JP-A-61-120853 (JP, U) 4-10540 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 27/00 E04B 1/24

Claims (3)

(57) [Claims] 1. An anchor bolt is buried in a foundation concrete, a column having a base plate having a bolt hole at a predetermined position is fitted to the anchor bolt, and the anchor bolt and the base plate are fixed with nuts. In a steel column base on which a steel column is erected on the foundation, a steel rod is assembled into a mesh shape, a sheet-like wire mesh having fixed intersections is horizontally buried in the foundation concrete above the anchor bolt, and a mesh The intersecting gap is defined as a predetermined position of the anchor bolt, and a bolt shaft is inserted through the gap. The anchor bolt is a U-shaped anchor bolt. Reinforced wire mesh characterized by multi-layered mesh wire mesh directly connecting the bolt shaft and other mesh wire mesh Steel column base used. 2. An anchor bolt is buried in a foundation concrete, a column having a base plate having a bolt hole at a predetermined position is fitted to the anchor bolt, and the anchor bolt and the base plate are fixed with nuts. In a steel column base on which a steel column is erected on the foundation, a steel rod is assembled into a mesh shape, a sheet-like wire mesh having fixed intersections is horizontally buried in the foundation concrete above the anchor bolt, and a mesh The intersecting gap is defined as a predetermined position of the anchor bolt, a bolt shaft is inserted through the gap, and the sheet-like wire mesh is fixed to a support structure such as a shaped steel standing upright outside the anchor bolt. A steel column base using a reinforcing wire mesh. 3. An anchor bolt is buried in a foundation concrete, a column having a base plate having a bolt hole at a predetermined position is fitted to the anchor bolt, and the anchor bolt and the base plate are fixed with a nut. In a steel column base on which a steel column is erected on the foundation, a steel rod is assembled into a mesh shape, a sheet-like wire mesh having fixed intersections is horizontally buried in the foundation concrete above the anchor bolt, and a mesh The intersecting gap is defined as a predetermined position of the anchor bolt, a bolt shaft is inserted through the gap, and the outer periphery of the sheet-shaped wire mesh is bent down to the outside of the vertical streaks and hoops arranged around the foundation concrete, and the basket is lowered. A steel column base using a reinforcing wire mesh, which is a part of a basic reinforcing bar arrangement.