JP2604435B2 - Pillar structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a column base structure of a steel structure or a steel reinforced concrete structure.

[Conventional technology]

When a conventional steel column is to be erected on a concrete foundation, the column base metal part made of steel plate or cast steel is integrally joined to the column base of the steel column by welding or bolting, and then buried in the concrete foundation. Means for fixing with a fixed anchor bolt are generally used. FIG. 5 is a longitudinal sectional view of an essential part showing an example of the column base structure as described above. In the figure, first, a steel column 1 made of steel material is used.
The column base metal 2 is integrally joined by welding and placed on a concrete foundation 3 via a central mortar 4 previously provided. In this case, since a predetermined number of anchor bolts 5 are buried in the concrete foundation 3, positioning is performed by bolt holes (not shown) drilled in the column base hardware 2. Thereafter, the mortar 6 is filled between the column base metal fitting 2 and the concrete foundation 3, and after the mortar 6 is sufficiently solidified,
The nut 8 is fastened by interposing the washer 7 to the anchor bolt 5 to fix the steel column 1. Reference numeral 9 denotes a mold, which regulates the outer dimensions when the mortar 6 is injected and filled.

[Problems to be solved by the invention]

In the above-mentioned conventional column base structure, after the column base metal 2 is placed on the central mortar 4, when the mortar 6 is filled in the gap between the column base metal 2 and the concrete foundation 3, air is sealed. There is a problem that a phenomenon of creating the cavity 10 occurs, and the mortar 6 does not completely adhere to the entire bottom surface of the column base hardware 2.

FIG. 6 is an explanatory view showing a flow state of the mortar 6 in the mold 9. In FIG. 6, what is indicated by a chain line is an outer contour of the column base metal fitting 2 in a plane. The most common example of the central mortar 4 is to form the planar shape into a quadrilateral as shown in the figure. When the mortar 6 is injected and filled from the direction of the arrow A through a container such as a hopper in the state as shown in FIG. 6, the mortar 6 flows along the streamline indicated by the arrow B, but the mortar 4 at the center exists. To do
The divided flows merge on the downstream side, and during this time, the air existing between the column base 2 and the concrete foundation 3 is sealed, and a cavity 10 is formed as shown by hatching.

The performance required for the column base structure includes the rigidity of the column base hardware and the fastening force of the anchor bolts, as well as the adhesion between the mortar and the column base hardware. If present, satisfactory column-base structure performance cannot be obtained, and there is a problem that seismic resistance is significantly reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems existing in the prior art and to provide a column base structure that can completely adhere a column base metal fitting to a mortar and that can greatly improve earthquake resistance.

[Means for solving the problem]

In order to achieve the above object, in the first invention, first, a steel column, a projection formed in a planar shape corresponding to the contour of a leg end surface of the steel column, and a bottom plate formed in a flat plate shape are provided. And a mortar to be poured after installation of the column base metal, and the column base metal and the concrete foundation are sandwiched between the mortar and the concrete base. In a column base structure joined via an anchor bolt and a nut buried therein, a column base metal fitting is provided at a position corresponding to the periphery of the central mortar within the outer contour of the protruding portion of the column base metal fitting. A technical means was adopted in which one or more holes for discharging air blocked due to the filling of the mortar with the concrete foundation were provided vertically through the hole to discharge the air.

Next, in the second invention, a steel column, a column base fitting including a projecting portion formed in a planar shape corresponding to the contour of a leg end face of the steel column and a bottom plate portion formed in a flat plate shape are integrally formed. Anchor bolt which joins, embeds the column base metal and the concrete foundation, sandwiches the central mortar previously provided on the concrete foundation, and the mortar to be injected after the installation of the column base metal, and buries in the concrete foundation. And one or more grooves penetrating in the horizontal direction in the central mortar, and within the outer contour of the projecting portion of the column base metal and the central mortar. At a position corresponding to the groove, one or a plurality of holes are formed by vertically penetrating holes for discharging air blocked due to the filling of the mortar between the column base hardware and the concrete foundation. Provided, was adopted the technical means that.

In the first aspect, it is preferable that the plane shape of the central mortar is a shape corresponding to a streamline of the mortar.

[Action]

Due to the above configuration, during the filling and filling of the mortar, the air interposed between the column base metal and the concrete foundation is easily exhausted from the holes provided in the column base metal and forms a cavity in the mortar. Can be completely avoided.

〔Example〕

FIGS. 1 and 2 are a vertical sectional view and a partial cross sectional plan view, respectively, showing a main part of a first embodiment of the present invention. The same parts are designated by the same reference numerals as in FIGS. 5 and 6. Shown.
In FIGS. 1 and 2, the column base metal fitting 2 is composed of, for example, cast steel, a projecting portion 21 formed in a planar shape corresponding to the contour of the leg end surface of the steel column 1, and a bottom plate portion 22 formed in a flat plate shape. A bolt hole (not shown) is formed at a position corresponding to the anchor bolt 5 while being integrally formed. Note that the planar contours of the projecting portion 21 and the bottom plate portion 22 are formed in a substantially square shape corresponding to the cross-sectional contour shape of the steel column 1. Next, reference numeral 23 denotes a hole, which is provided at a position substantially corresponding to the planar contour of the central mortar 4 so as to penetrate the column base metal 2 in the vertical direction.

According to the above configuration, after the steel column 1 and the column base metal fitting 2 are welded and joined, they are placed and positioned on the central mortar 4 previously provided on the concrete foundation 3, and the mortar 6 is placed in the formwork 9 with arrows. Inject and fill as indicated by A. In this case, the mortar 6 flows as shown in FIG. 6 and tends to seal the air particularly near the central mortar 4.
As shown in FIG. 1 and FIG. 2, the hole 23 is provided in the column base metal member 2. Therefore, even if the sealed air exists as described above, it can be easily discharged from the hole 23. It is.
Therefore, the mortar 6 can be completely filled into the bottom surface of the column base metal without any hindrance to the fluid filling.
The generation of cavities as shown in FIGS. 6 and 6 can be eliminated.

Next, FIG. 3 is a partial cross-sectional plan view showing a second embodiment of the present invention, and the same portions are denoted by the same reference numerals as in FIGS. 1 and 2. In FIG. 3, reference numeral 41 denotes a groove which is provided substantially in the same direction as the injection direction A of the mortar 6 and penetrates in the horizontal direction. The hole 23 provided in the column base metal fitting 2 is
It may be provided so as to face the groove 41 described above.

When the mortar 6 is injected and filled in the direction of arrow A according to the above configuration, the mortar 6 flows in the same manner as described in the above embodiment, and also flows into the groove 41 provided in the central mortar 4. Then, the mortar 6 flowing in the groove 41 passes through the groove 41 earlier than the mortar 6 flowing in other parts and reaches near the edge of the column base 2, so that the air is not sealed and the column base 2. Adhere completely to the bottom of 2. Groove 41
Since the hole 23 is provided so as to face the air, even if the mortar 6 is filled in the groove 41 or the air is sealed when the mortar 6 flows, the air can be easily discharged.

FIG. 4 is a plan view of an essential part showing a third embodiment of the present invention, and the same parts are denoted by the same reference numerals as in FIGS. 1 to 3. In FIG. 4, the central mortar 4 is formed so that its planar shape is elliptical, and that the mortar 6 has a long axis in the injection flow direction. Other configurations are the same as those in the first embodiment.

With the above configuration, the steel column and the column base metal are joined together (all not shown) and placed on the central mortar 4 in the same manner as in the above embodiment, and the mortar 6 is injected and filled in the direction of arrow A. . In this case, the central mortar 4 has an elliptical planar shape and is provided so that its major axis coincides with the flow direction of the mortar 6. They almost match. Therefore, the so-called fluid resistance is small, and the streamlines on the downstream side of the central mortar 4 can be prevented from being disturbed. As in the case of the first embodiment, the sealed air is provided in the column base metal fitting 2. 23 (see FIGS. 1 and 2)
The mortar 6 can completely eliminate the air sealing action.

In this embodiment, an example is shown in which the cross-sectional shape of the steel column and the planar shape of the column base metal are formed to be substantially square.
The same applies to other quadrilaterals, circles and other geometric shapes other than squares. The column base metal can be formed of a steel plate or a steel material, instead of being formed of cast steel. Further, the holes to be provided in the column base metal can have a cross-sectional shape other than a circular shape, and the number of installations can be arbitrarily selected. Next, the number of horizontal through grooves to be provided in the central mortar is not limited to one, but may be plural. The plane shape of the central mortar can be any shape other than square or elliptical, but if no horizontal groove is installed, the curve corresponding to the streamline of the mortar will be part of the contour. It is preferable to form it in a shape that does.

〔The invention's effect〕

Since the present invention has the configuration and operation as described above, it is possible to avoid air sealing when filling and filling mortar between the column base hardware and the concrete foundation, and to completely prevent the occurrence of cavities due to this. can do. Therefore, it is expected that the mortar is completely adhered to the bottom surface of the column base hardware, and that the mortar can greatly improve the seismic performance required for the column base structure.

[Brief description of the drawings]

1 and 2 are respectively a longitudinal sectional view and a partial cross-sectional plan view of a main part showing a first embodiment of the present invention, and FIG. 3 is a partial cross-sectional plan view showing a second embodiment of the present invention. 4 is a plan view of a main part showing a third embodiment of the present invention, FIG. 5 is a longitudinal sectional view of a main part showing an example of a conventional column base structure, and FIG. 6 is a flow state in a mortar mold. FIG. 1: steel column, 2: column base hardware, 3: concrete foundation, 4: central mortar, 6: mortar, 23: hole, 41: groove.

(72) Inventor Isamu Yamamoto 1-9-1 Kitahama-ku, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Wakamatsu Plant of Hitachi Metals Co., Ltd. (72) Osamu Narushige 1-9-1 Kitahama, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture No. 1 Inside the Wakamatsu Plant, Hitachi Metals Co., Ltd. (72) Inventor Tomio Ito 1-9-1 Kitahama, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Wakamatsu Plant, Hitachi Metals Co., Ltd. (72) Kuniaki Sato 1 Motogasaka, Minato-ku, Tokyo 2-7-7 Kashima Construction Co., Ltd. (72) Inventor Yoshihiro Nakamura 1-2-7 Moto-Akasaka, Minato-ku, Tokyo 1-72 Kashima Construction Co., Ltd. (72) Akio Tomita 1-2-2 Moto-Akasaka, Minato-ku, Tokyo No. 7 Kashima Construction Co., Ltd. (72) Inventor Shunichi Yamada 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Shozo Maeda 1-2-7 Moto-Akasaka, Minato-ku, Tokyo No. Kashima Construction Co., Ltd. (56) References JP-A-54-6306 (JP, A) JP-A-61-216949 ( P, A) JP Akira 49-38445 (JP, A)

Claims (3)

(57) [Claims] 1. A steel column, and a column base fitting comprising a flat plate-shaped bottom plate and a projection formed in a planar shape corresponding to the contour of a leg end face of the steel column, and integrally joined together.
Anchor bolts and nuts that sandwich the column base metal and the concrete foundation, sandwich the center mortar previously provided on the concrete foundation and the mortar to be injected after the column base metal is installed, and are embedded in the concrete foundation. In the column base structure which is joined through, in a position corresponding to the periphery of the center mortar within the outer contour of the protrusion of the column base metal,
A column base provided between the column base hardware and the concrete foundation, one or a plurality of holes are provided vertically through the hole for discharging air blocked due to the filling of the mortar. Construction. 2. A steel column, and a column base fitting comprising a flat plate-shaped bottom plate and a projection formed in a planar shape corresponding to the contour of a leg end face of the steel column, and integrally joined together.
Anchor bolts and nuts that sandwich the column base metal and the concrete foundation, sandwich the center mortar previously provided on the concrete foundation and the mortar to be injected after the column base metal is installed, and are embedded in the concrete foundation. In the column base structure which is joined through the mortar, one or a plurality of grooves penetrating in the horizontal direction are provided in the central mortar, and correspond to the groove of the central mortar within the outer contour of the protruding portion of the column base hardware. At the position, one or a plurality of holes are provided between the column base metal and the concrete foundation for vertically exhausting holes for discharging air blocked due to the filling of the mortar. Column base structure. 3. The mortar according to claim 1, wherein the mortar has a planar shape corresponding to a streamline of the mortar.
Column base structure as described.