JPH0715183B2 - Connection structure of precast steel concrete columns - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a connecting structure for connecting concrete columns to a butt position when constructing a multi-storey building using precast steel concrete columns.

(Prior art) In recent years, precast steel-reinforced concrete pillars (hereinafter abbreviated as PSC pillars) manufactured and managed in advance in the factory are used in order to shorten the construction period, simplify the construction, and stabilize the quality. A new construction method has been developed. As shown in Fig. 6, this construction method has PSC columns 1,1 ...
Are connected to each other in a butt arrangement, and each PSC column 1,1…
Precast large girders 3 and 3 are hung and fixed between the beam connecting projections 2 and 2 which are projected to the side of.

The connection of this conventional PSC column 1,1 uses the PSC column 1 in which the internal steel frame 4 is projected to the end face as shown in FIG. 7 to FIG. 8, and the steel frames 4, 4 are butted against each other. After fixing the connecting plate 5 by straddling both steel frames 4 and 4 with bolts 6, post-casting concrete 7 is placed on the exposed portions of the steel frames 4 and 4.

(Problems to be Solved by the Invention) Generally, in a steel-framed concrete column, it is preferable that the steel frame and the concrete share a vertical load at a constant rate, and a uniform cast-in-place concrete column or a single PSC is used throughout. In the column, steel frame and concrete simultaneously support vertical load.

On the other hand, in the case of the conventional PSC column connection structure described above, only the steel frame is projected from the PSC column, and after connecting this, the space between the upper and lower columns is filled with post-cast concrete, The load ratio of post-cast concrete is small,
The load on the steel frame at the connecting part becomes larger than that at other parts, so that it becomes the same state as when there is a cross-section defect in the column after connection, and stress concentration tends to occur in that part in an emergency. . Therefore, conventionally, it was necessary to use a steel frame having a strength commensurate with that, and there was a problem that the amount of steel frame used in the entire PSC column was large and it was uneconomical.

Further, there is a problem that after the connection of the steel frames, the next work cannot be performed unless the post-cast concrete shows a predetermined strength, the construction period becomes long, and the advantage of precasting the columnar body is small.

In view of such a conventional problem, the present invention, in the connection portion of the PSC column body, the vertical load sharing ratio between the steel frame and the concrete does not significantly change from other precast portions, and the connection of the PSC column body can shorten the construction period. The purpose is to provide the structure.

(Means for Achieving the Problem) The feature of the present invention that solves the above-mentioned conventional problems and achieves the intended purpose is that a steel frame is embedded in the longitudinal direction, and end faces are joined to each other in a butted arrangement. A pair of precast steel-framed concrete columns are provided with concrete cutouts at the periphery of each joint end surface, and the end faces of the columns are provided with a base plate that is integrated with the steel frame and the peripheral edge back surface is exposed to the concrete cutouts. The base plates are overlapped with each other to join the precast steel-framed concrete columns, and the overlapped base plates are integrated with each other by fastening means such as bolting or welding.

(Operation) According to the connection structure of the PSC columnar body of the present invention, since the precast concrete is in direct contact with the base plate at the joint end surface of the PSC columnar body, the upper PSC columnar body bears the entire bone and concrete. The vertical load is always transmitted as it is through the base plate to the whole of the lower PSC pillar's gold frame and the entire concrete, without excessively loading the steel frame on the extreme vertical load. Also, the load sharing ratio of concrete does not differ much from other precast parts.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS.

In the figure, 11a is a lower PSC column which is to be connected to each other, and 11b is an upper PSC column. Both PSC columns 11a, 11b are made of factory-made concrete sections 12a, 12b having square cross sections, and steel frames 13a, 13b having cross-shaped cross sections and high-strength muscles arranged around them. The main bars 14a and 14b are embedded and molded.

At the upper end of the lower PSC column 11a, a concrete cutout portion 15a is formed in a rectangular ring shape along the upper end periphery outside the position where the steel frame 13a is embedded.

A sleeve joint 16 for connecting main reinforcements is embedded corresponding to each main reinforcement 14a with one end opened in the concrete cutout portion 15a, and the upper end of the main reinforcement 14a is inserted into the lower half of each sleeve joint 16. Reference numeral 17 in the figure is a grout inlet for a sleeve joint.

In addition, a base plate 18a integrally welded to the end of the steel frame 13a is provided on the upper end surface of the PSC column 11a in close contact with the end surface of the remaining concrete portion 12a excluding the concrete cutout portion 14a. As the base plate 18a, the one whose peripheral edge is formed in a flange shape to the size of the concrete cutout portion is used. And
A main bar through hole 19 is opened in the peripheral portion.

On the other hand, on the lower side of the upper PSC column 11b, the above-mentioned lower PSC
Similar to the upper end of the pillar 11a, a concrete cutout portion 15b is formed in a rectangular ring shape along the lower end periphery on the outer side of the position where the steel frame 13b is embedded.

A base plate 18b integrally welded to the end of the steel frame 13b is provided on the lower end surface of the PSC column 11b in close contact with the end surface of the remaining concrete portion 12b excluding the concrete cutout portion 15b. The base plate 18b has a flange-like peripheral edge protruding to a concrete cutout position.

Also, each main bar 14b in the PSC column 11b is
5b, and penetrates the peripheral edge of the base plate 18b.

After each PSC pillar 11a, 11b molded in the factory in the shape as described above is carried into the construction site, the lower PSC pillar 11a is erected, and then the upper PSC pillar as shown in Fig. 1. It projects below 11b. Insert the tip of the main bar 14b into the sleeve joint 16 by penetrating the lower base plate 18a,
The upper and lower base plates 18a, 18b are superposed on each other and temporarily fixed by a bolt nut 20. In this state, the peripheral edges of both base plates 18a, 18b are fixed by welding 21 and the grout 22 is injected into each sleeve joint 16 to connect the main bars 14a, 14b.

After connecting the steel frames 13a, 13b and the main bars 14a, 14b to each other in this manner, both concrete notch parts 15a, 15b arranged to be connected to each other are filled with post-casting concrete 23 to both PSC columns. The connection between the bodies 11a and 11b is completed.

(Effect of the invention) As described above, in the connection structure of the PSC columnar body of the present invention, the respective precast concrete parts are in close contact with the base plates on the end faces of both PSC columnar bodies, and the base plate is integrated with the steel frame. Therefore, the upper PSC
Even before the post-casting concrete is placed, the vertical load of the pillars will be shared by the concrete parts of both PSC pillars and the steel frame at a predetermined ratio and will be transmitted to the lower PSC pillars. The load bearing ratio does not increase,
Even at the connecting portion, the same strength as other portions can be economically obtained.

In addition, in the present invention, since strength against vertical load is obtained by integrating the base plates, it is not necessary to wait for the strength of the post-cast concrete to develop, and the construction period can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional view showing a connecting structure of the present invention, FIG. 2 is a side view of an end portion of a lower PSC column, and FIG. 3 is AA in FIG.
A line sectional view, FIG. 4 is a side view of an end portion of the upper PSC column, FIG. 5 is a sectional view taken along line BB in FIG. 4, and FIG. 6 is a side view of an example of assembly by a conventional precast column. Fig. 7 is a sectional view showing a conventional precast column connecting structure, and Fig. 8 is a sectional view.
It is the CC sectional view taken on the line in the figure. 11a, 11b …… PSC column, 12a, 12b …… Concrete part, 13
a, 13b …… Steel, 14a, 14b …… Main bar, 15a, 15b …… Concrete notch, 16 …… Sleeve joint, 17 …… Grout injection port, 18a, 18b …… Base plate, 19 …… Main bar through hole , 20 …… Bolt nut, 21 …… Welding, 22 …… Grout, 23 …… Post-cast concrete.

Claims (1)

[Claims] 1. A concrete notch is provided at each joint end face peripheral edge of a pair of precast steel-concrete concrete columns in which a steel frame is embedded in the longitudinal direction and whose end faces are joined to each other in a butted arrangement, and at the end faces of the column bodies. A base plate integrated with the steel frame and having a peripheral back surface exposed to the concrete cutout portion is provided, the base plates are overlapped with each other to join the precast steel concrete columns, and the base plates overlapped with each other are provided. Connection structure of precast concrete columns that are integrated by fastening means such as bolting or welding.