JP3198074B2 - Column base structure in steel structure and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column base structure in a steel frame structure in which a lower end of a steel column is connected to a foundation of a building, and a method of manufacturing the same.

[0002]

2. Description of the Related Art An example of the prior art will be described with reference to FIG. 2 showing an embodiment of the present invention. Conventionally, a mirror-shaped level adjusting mortar table 4 is provided at the center of the top end face 2 of the foundation 1 in FIG. 2 at a position corresponding to the column 3, and a top surface of the level adjusting mortar table 4 corresponding to each column 3 is provided. The base plate 5 welded to the lower end of the column 3 is placed on the mortar base 4 for level adjustment, and the upper end of the column main reinforcement 6 (including anchor bolts and the like) is fixed to the base plate 5. 5, a non-shrink mortar 8 is injected into the mold 7 to fill the gap between the base top end face 2 and the base plate 5, and after the mortar is solidified, the mold 7
Had been removed. That is, the steel formwork 9, support bar 10, hoop bar 11, etc. of the present invention shown in FIG. 2 were not arranged. Therefore, when a large rolling load acts on the column 3 due to an earthquake or the like, cracks enter the non-shrinkable mortar 8 having no rebar inside, the non-shrinkable mortar 8 between the cracks scatters, and the lower part of the base plate becomes hollow. ,
The exposed column main bar 6 was buckled, the column 3 was tilted, and the building could collapse, and the above-mentioned phenomenon occurred frequently during the Great Hanshin Earthquake.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to prevent cracks and scattering from occurring in the non-shrinkable mortar between the top surface of the foundation and the column base plate even when a large rolling load is applied to the column. And

[0004]

According to a first aspect of the present invention, a male screw portion above a level adjusting nut screwed into a male screw portion at an upper end portion of a pillar main bar projecting upward from four corners of a top end face of a foundation is provided. It extends through the hole of the base plate fixed to the lower end of the column and extends upward, and a tapered hole that opens upward is provided in the upper half of the hole, and this tapered hole is integrated from the lower surface of the disk portion at the upper end of the pedestal. The caulking part at the upper end of the pillar main bar is placed in the tapered hole that opens upward on the caulking pedestal, and the base plate is fixed while being supported by the level adjustment nut, A column base structure in a steel structure, wherein a reinforcing bar is arranged in a gap between a top end face of a foundation and a base plate, and the gap is filled with non-shrink mortar.

According to a second aspect of the present invention, a base plate fixed to the lower end of a pillar is fixed to an upper end of a pillar main bar projecting upward from four corners of the top end face of the foundation, and is supported by the top end face of the foundation and has an injection port and air. The outer peripheral surface of the base plate is fastened with a mold having a hole, a reinforcing bar is arranged in the gap between the top end face of the foundation and the base plate, and non-shrink mortar is injected from a funnel attached to the inlet, and the gap is When the non-shrinkable mortar fills up and overflows from the air vent hole, attach a lid to the air vent hole, pressurize the gap until the mortar is at least half-fixed, leaving the non-shrink mortar in the funnel up to the predetermined height A method of manufacturing a column base structure in a steel structure, characterized in that the column base structure is maintained in a state.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. Also in the anchor bolt method, the graft reinforcing and filling methods are the same.
In FIG. 2, the upper end of a column main bar 6 provided in the foundation 1 projects vertically from four corners of a top end surface 2 (square viewed from above as shown in FIG. 4) of the foundation 1, and the column 3 The base plate 5 welded to the lower end of the base plate is fixed in a horizontal posture. That is, the base plate 5 is supported on a level adjusting nut 13 screwed to the male screw portion at the upper end of the column main bar 6, and the male screw portion at the upper end of the column main bar 6 passes through the hole 14 of the base plate 5 and rises upward. And the upper end is swaged to the upper end surface of the swage base 15 to form a hemispherical swaged portion 16.
Is formed. The upper half of the hole 14 is formed as a tapered hole 14a opened upward, and a tapered portion 15a integrally extending downward from the lower surface of the disk portion at the upper end of the caulking base 15 is in close contact with the tapered hole 14a. And caulking pedestal 15
Also has a tapered hole 15b that opens upward. The caulking portion 16 fits the hole 14 of the base plate 5 at the upper end of the column main reinforcing bar 6, then heats and softens the upper end of the column main reinforcing bar 6 with a high-frequency heating device or the like, fits the caulking pedestal 15 there, and forms an appropriate caulking device. Obtained by tightening. The tapered hole portion 14a is effective for securing a space for setting the high-frequency heating device before fitting the caulking pedestal 15, and for improving the stability of the caulking pedestal 15. Of course, there is no level adjustment mortar table 4 or wooden formwork 7 shown by a two-dot chain line. In addition, 12 in FIG. 2 shows a part of the hoop streak incorporated in the foundation 1. Further, the number of the column main bars 6 may be more than four.

[0007] The steel formwork 9 is integrally provided with a horizontal narrow flange portion 9a at the lower end edge of the main body of the vertical strip steel plate,
The lower surface of the flange portion 9a is seated on the foundation top end surface 2. As shown in FIG. 3, one end of each of a number of horizontal support bars 10 is welded to the inner surface of the main body of the steel formwork 9. In the illustrated embodiment, the hoop bars 11 are provided on all the support bars 10.
And is fixed by a binding wire (not shown). When viewed from above, the hoop streaks 11 are substantially square (FIG. 4) that surround the column main streaks 6 at the four corners in close proximity. The support bars 10 and the hoop bars 11 are located substantially at the center in the vertical direction of the gap A surrounded by the steel formwork 9 between the base top end surface 2 and the base plate 5. The gap A is filled with a non-shrink mortar 18.

As shown in FIG. 3, the steel formwork 9 is composed of two substantially L-shaped pieces as viewed from above, and each piece has a fixing flange 20 which is bent at 45 degrees from the formwork body at both ends.
And each flange 20 has two opposed flanges 20.
Is provided with a hole 22 for stopping the bolt with a bolt 21 (FIG. 4). 3 has a funnel-shaped non-shrinkable mortar injection port 23 opened upward at the center of the left side, and the right-side mold 9 has the same shape.
Has an air vent hole 24 having the same shape as the injection port 23 at a position facing the injection port 23. A substantially L-shaped hoop streak 11 (a half that becomes a hoop after assembling as shown in FIG. 4) in each of the two divided molds 9 has a short bent portion 11a bent inward at right angles at both ends. , The bent portion 11a corresponds to the form 9 of FIG.
2 and 4, when the outer peripheral surface of the base plate 5 is fastened and fastened, it overlaps with the main body of the opposing hoop streak 11, and forms a substantially square hoop as described above. In the state of FIG. 3, the hoop muscles 11 are fixed to all or a part of the support muscles 10 on the adjacent side by binding wires.

The formwork 9 divided as shown in FIG. 3 is placed on the top surface 2 of the foundation as shown in FIG. 2, and the hoop streaks 11 are fitted so as to closely surround the main column 6 from the outside. Is passed through the hole 22 in FIG. 3 and tightened with a nut 26, and the outer peripheral surface of the base plate 5 is tightened (fastened) at the upper part of the main body of the formwork 9 to substantially seal the gap A. Then, as shown in FIG. 5, the funnel 27 is fitted tightly into the inlet 23 while maintaining the liquid tightness.
7, the non-shrink mortar 18 is injected into the gap A, and when the mortar 18 is filled in the gap A and the mortar starts to overflow from the air vent hole 24, a lid 28 made of, for example, plywood is put on the air vent hole 24 and A weight 29 is placed on the top to close the air vent hole 24, and the non-shrinkable mortar 18 is put into the funnel 27 to a height H (for example, 300 mm) from the gap A, and is kept there for, for example, 2 hours (until the mortar is partially fixed) After the holding, the funnel 27 is removed from the inlet 23. Accordingly, the inside of the gap A is maintained under a pressurized state by receiving the mortar pressure of the head H until the mortar is semi-fixed.
0, a durable grout layer with reinforcing bars reinforced with hoop bars 11) (approximately similar to reinforced concrete) is obtained. In FIG. 4, L1 is the dimension between the column main bars 6, and L2 is the base plate 5.
Is the outer diameter dimension of

In the present invention, it is important that reinforcing steel is incorporated in the non-shrink mortar 18 filling the gap A. From this viewpoint, the following various deformations can be considered. (1) The support bars 10 welded to the inner surfaces of the main body of the left and right form frames 9 in FIG. 3 are extended so that the opposed support bars 10 overlap when assembled as shown in FIG. Then, the reinforcing effect is greatly improved. (2) The welding of the support bars 10 to the formwork 9 is stopped, and a reinforcing bar assembly separate from the formwork 9 (two sets of the support bars 10 and the hoop bars 11 of FIG. Prepare the 3D)
Before mounting the formwork 9 (without the support bar 10), the two sets of reinforcing bar assemblies are arranged so as to surround the column main bar 6 in the gap A using a dice stand (not shown), Then, a mold is attached, and the non-shrink mortar 18
Inject. In that case, the formwork can be recycled,
The mold can be made of, for example, plywood other than steel, and cost reduction can be expected. Of course, if the base plate 5 is tightened and secured by employing the form 9 shown in FIGS. 1 to 4, there is an advantage that the breaking strength is increased by the form. (3) The hoop streaks 11 can be removed from FIG. In such a case, if the support bar 10 is lengthened and the main bar 6 is held from the outside by the support bar to be forked, and the function of the hoop bar 11 is also used, for example, when the mortar outside the column main bar 6 is missing. Also, like the hoop muscle 11, the support muscle exerts sufficient resistance against the buckling of the column main muscle 6. (4) When removing the support bars 10 from FIG. 3 and placing the hoop bars 11 in the gap A, use an appropriate dice table,
The hoop muscle 11 can be fixed to the column main muscle 6 with a binding wire. A plurality of hoop streaks 11 may be employed to enhance the reinforcing effect. In this case, the structure of the mold is simplified, so that the cost can be reduced.

[0011]

According to the first aspect of the present invention, since the reinforcing bars (for example, the support bars 10 and the hoop bars 11) are built in the non-shrinkable mortar 18 in the gap A, the breaking strength of the non-shrinkable mortar 18 is large. To prevent the destruction of the non-shrink mortar 18 even during an earthquake in which a large rolling load acts on the column 3 and to maintain the stress due to the horizontal load (by frictional force), preventing the buckling of the main bar 6. A possible effect occurs. Further, the tapered hole portion 14a is effective for securing a space for setting the high-frequency heating device before fitting the caulking pedestal 15 and improving the stability of the caulking pedestal 15. According to the second aspect of the present invention, since the non-shrink mortar 18 in the gap A can be solidified in a pressurized state, the density of the non-shrink mortar 18 increases, and the bonding strength with the reinforcing steel bar also increases. A column base that can maintain sufficient strength even during seismic intensity is obtained.

[Brief description of the drawings]

FIG. 1 is a completed perspective view of a column base.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an exploded perspective view of a steel mold.

FIG. 4 is a cross-sectional plan view.

FIG. 5 is a schematic longitudinal sectional view showing a manufacturing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 foundation 2 top end face 3 pillar 5 base plate 6 pillar main reinforcing bar 10 support bar (rebar) 11 hoop bar (rebar) 18 non-shrink mortar 23 inlet 24 air vent hole 27 funnel 28 lid A gap H height

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 27/00 E02D 27/01

Claims (2)

(57) [Claims] 1. A male screw portion above a level adjusting nut screwed into a male screw portion at an upper end portion of a pillar main bar protruding upward from four corners of a top end face of a foundation penetrates a hole of a base plate fixed to a lower end of a pillar. The upper half of the hole is provided with a tapered hole that opens upward, and the tapered portion that is integrally extended downward from the lower surface of the disk portion at the upper end of the caulking pedestal is closely attached to this tapered hole. The caulked portion at the upper end of the pillar main bar is placed in the tapered hole that opens upward to the caulking pedestal, and the base plate is fixed with the base plate supported by the level adjustment nut, and the gap between the top end surface of the foundation and the base plate A column structure in a steel frame structure, wherein a reinforcing bar is arranged in a space, and the gap is filled with non-shrink mortar. 2. A mold having a base plate fixed to the lower end of a pillar fixed to the upper end of a pillar main bar projecting upward from four corners of the top end face of the foundation, and supported by the top end face of the foundation and having an inlet and an air vent hole. The outer peripheral surface of the base plate is fastened with a frame, a reinforcing bar is arranged in the gap between the top end face of the foundation and the base plate, and non-shrink mortar is injected from the funnel attached to the inlet, and the non-shrink mortar is injected into the gap. At the time of filling and overflowing from the air vent hole, attach a lid to the air vent hole, leave the non-shrink mortar up to a predetermined height in the funnel, and keep the inside of the gap pressurized until at least the mortar is partially fixed. A method for manufacturing a column base structure in a steel frame structure, characterized in that: