JPH042144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" This invention relates to a filled steel pipe concrete column.

``Prior Art'' Conventionally, in a filled steel pipe concrete column in which a steel pipe is filled with concrete, a stiffener ring is attached to the outer surface of the steel pipe as a joint structure with a beam connected to the column. Rigidity is ensured by welding a beam to this stiffener ring.

``Problem to be solved by the invention'' However, in the case of the above-mentioned filled steel pipe concrete column, the beam is simply welded to the outer peripheral surface of the steel pipe, so the vertical load acting on the beam is first transmitted to the steel pipe. , and then it is transmitted to the concrete due to the adhesive force between the steel pipe and the concrete.

Therefore, the steel pipe is subjected to compressive force in the axial direction, and this compressive force causes strain, and when this strain increases, the steel pipe may exceed the Mises yield condition or cause local buckling. Sometimes. In this case, the confining effect of the steel pipe (by tightening the concrete to prevent it from expanding outward due to the circumferential stress of the steel pipe)
Therefore, there was a problem that the column had no choice but to have a larger cross-sectional area than necessary. .

In order to solve the above problems, the present applicant previously provided a joint structure as shown in FIGS. 7 and 8. This is done so that the position where the beam b inside the steel pipe a is joined is continuous with the web c of the beam b.
A steel plate d which acts as a stiffener is attached.

According to this structure, the load applied to beam b is the steel pipe a
is transmitted to the steel plate d, and from this steel plate d to the concrete e. That is, the vertical load is directly transmitted from the beam b to the concrete e, and the steel pipe a receives almost no axial stress. Therefore, the steel pipe a will not exceed the Mises yield condition or cause local buckling, and will be able to fully exhibit the confining effect, and can be expected to sufficiently increase the yield strength of the concrete e. Therefore, it is possible to reduce the cross-sectional area of the column.

However, in this structure, since the steel plate d is provided across the center of the steel pipe a,
When filling concrete e into steel pipe a, it is not possible to place a concrete pouring pipe such as a tremie pipe in the center of steel pipe a, which is the optimal position, and it is difficult to uniformly fill concrete into steel pipe a. The problem remains that it is difficult.

This invention has been made in view of the above circumstances, and provides a filled steel pipe concrete column that can fully expect the effect of confining steel pipes and also allows filling of concrete into the steel pipes uniformly and easily. The purpose is to

``Means for Solving the Problems'' This invention provides a method for adding concrete to the inner center of a steel pipe at a position where a beam is joined, extending in the axial direction of the steel pipe and filling the steel pipe with concrete. A pipe for inserting the pouring pipe is arranged only at the position where the steel pipe and the beam are joined, and a stiffener is installed between this pipe and the inner surface of the steel pipe so as to be continuous with the beam. It is characterized in that the concrete is provided over the entire cross section of the internal space of the steel pipe.

"Operation" According to the present invention, the load applied to the beam is directly transmitted to the concrete by the stiffener, and the compressive force applied to the steel pipe is reduced. In addition, when filling concrete into a steel pipe, the concrete casting pipe such as a tremie pipe is placed in the center of the steel pipe by passing the concrete casting pipe such as a tremie pipe into the center of the steel pipe. can be passed through, making it easy and uniform to fill with concrete. That is, the pipe acts as a guide for the concrete pouring pipe. Moreover, since the interior of this space is also filled with concrete eventually, the filled steel pipe concrete column can secure the desired strength.

"Embodiments" Examples of the present invention will be described below with reference to FIGS. 1 to 6.

First, a first embodiment will be described with reference to FIGS. 1 to 4. FIGS. 1 and 2 are diagrams showing a schematic structure of the joint structure of this first embodiment, and reference numeral 1 in the figures indicates a filled steel pipe concrete column. This filled steel pipe concrete column (hereinafter simply referred to as column) 1
The structure has a structure in which the inside of a steel pipe 2 is filled with concrete 3, and beams 4 are joined to the outer surface to form the frame of the structure.

To explain the structure of the joint part of the column 1, that is, the position where the beam 4 is joined, a pipe 5 with a circular cross section and a length approximately equal to the beam size of the steel pipe 2 is located at the center inside the steel pipe 2. They are arranged along the axial direction. The inner diameter of this pipe 5 is set to be large enough to allow a tremie pipe used for filling concrete 3 into the steel pipe 2 to be inserted therethrough, as will be described later. Also,
Stiffeners 6 are provided between the pipe 5 and the inner surface of the steel pipe 2. These stiffeners 6...
are formed of a steel plate, and both ends are welded and fixed to the inner surface of the steel pipe 2 and the outer surface of the pipe 5, respectively, so as to be continuous with the web 4a of the beam 4, and are connected to each other via the pipe 5. Further, disk-shaped bearing pressure plates 7 are horizontally attached to the lower ends of these stiffeners 6.

In addition, as shown in FIG. 3, at the interface between the steel pipe 2 and the concrete 3 filled inside it,
It is desirable to form an unbond treatment layer 12 to prevent these adhesion (treatment materials for forming this unbond treatment layer 12 include, for example,
It is possible to use paraffin, asphalt, etc.) Further, it is desirable that the steel pipe 2 is provided with a deformation absorbing portion that absorbs deformation (i.e., shrinkage) in the axial direction without restricting it. Furthermore, it is optional to increase the strength of the concrete 3 by inserting reinforcing bars into the concrete 3 or arranging prestressed steel.

Based on the above configuration, in this filled steel pipe concrete column, the vertical load applied to the beam 4 is transmitted to the stiffeners 6 through the steel pipes 2, and immediately transmitted from the stiffeners 6 to the concrete 3, and the vertical load applied to the beam 4 is transmitted to the concrete 3. Gives a compressive force in the direction. This stiffener 6...
The load is reliably and sufficiently transferred from the stiffeners 6 to the concrete 3 by pressing the concrete 3 with bearing plates 7 attached to the stiffeners 6. Therefore, almost no axial compressive force is applied to the steel pipe 2, and it is possible to prevent the steel pipe 2 from exceeding the Mises yield condition or causing local buckling, and the confining effect of the steel pipe 2 can be sufficiently maintained. You can expect it.

Note that if the steel pipe 2 and the concrete 3 are in an unbonded state by the unbonding treatment layer 12, it is possible to prevent the steel pipe 2 from receiving compressive force due to the compression of the concrete 3. If axial deformation is not restricted by providing this, no compressive force will act on the steel pipe 2, and the above effect can be further enhanced.

Next, with reference to FIG. 4, a construction method for the pillar 1 having the above-mentioned joint structure will be described. First, after setting up the steel pipe 2 at a predetermined position and joining the beams 4...
A tremie tube 8 is inserted into the steel tube 2 from the upper part of the steel tube 2, and is passed through the tube 5 disposed at the center of the steel tube 2. Then, the concrete 3 is press-fitted into the steel pipe 2 through the tremie pipe 8, and the tremie pipe 8 is gradually pulled up while keeping the tip (lower end) of the tremie pipe 8 always buried in the concrete 3. As a result, the pressed concrete 3
gradually rises inside the steel pipe 2 and is fully filled into every corner of the steel pipe 2. According to the column having the above structure, the tremie pipe 8 can be placed in the center of the steel pipe 2, which is the optimum position, so that the concrete 3 can be press-fitted into the steel pipe 2 uniformly, and uneven pouring can be avoided. It never occurs. In addition, since sufficient clearance is secured inside the steel pipe 2 at the joint part, the rise of the concrete 3 is not hindered. Furthermore, since the tube 5, which acts as a so-called guide for the tremie tube 8, has a structure that corresponds only to the joint portion, the material can be reduced and it can be manufactured easily.

Furthermore, since the inside of the pipe 5 is also filled with concrete 3, and the entire space inside the steel pipe 2 is filled with concrete 3, the column 1 exhibits the desired strength. In other words, since the pipe 5 is provided only at the joint part, when pouring concrete 2 while pulling the tremie pipe 8 upward from the bottom of the steel pipe 2 as described above, the pipe 5 covers all of the inside of the steel pipe 2. The entire cross section, including the inner part of the pipe 5, is reliably filled without interfering with the filling action of the concrete 3 into the space across the cross section. In addition, when providing the unbond treatment layer 12, the concrete 3
A treatment material may be applied to the inner surface of the steel pipe 2 before press-fitting.

The first embodiment has been described above, and next, the second embodiment will be described with reference to FIG. In the embodiment described below, the same components as in the first embodiment described above are designated by the same reference numerals as in FIGS. 1 and 2, and detailed explanation thereof will be omitted.

In this second embodiment, the pressure plate 9 has a substantially semicircular shape, and the pressure plate 9 has the same structure as the first embodiment except that an air hole 10 is formed in the pressure plate 9. . According to the filled steel pipe concrete column of the second embodiment, not only can the same effects as in the first embodiment be obtained, but also when filling the concrete 3 into the steel pipe 2, the concrete 3 can be press-fitted using a tremie pipe. When the poured concrete 3 rises through the joint, the air existing at the bottom of the bearing plate 9 flows through the air holes 10.
There is no risk of air being trapped here. Therefore, the concrete 3 is reliably filled in the lower part of the bearing pressure plate 9 without any gaps, and the pressing force of the bearing pressure plate 9 can be reliably transmitted to the concrete 3.

Next, a third embodiment will be described with reference to FIG. This third embodiment has the same structure as the first embodiment, except that the cross-sectional shape of the pipe 11 disposed at the center of the steel pipe 2 is a rectangle large enough to allow the tremie tube to be inserted therethrough. has been done. In the filled steel pipe concrete column of this third embodiment, the same effects as those of the first embodiment can be obtained, and
It can be constructed using a similar method. It should be noted that, in this third embodiment as well, the shape of the bearing pressure plate 7 may of course be made into a substantially semicircular shape as in the second embodiment.

The embodiments of this invention have been described above, but
The present invention is not limited to the above embodiments, and for example, the shape of the pipe, the stiffener, or the bearing plate disposed within the steel pipe may be changed as appropriate. Also,
It is also conceivable to provide a communication hole in the stiffener through which concrete can flow so that concrete can flow horizontally at the joint so that the concrete can be filled more uniformly.

Note that since the load is transmitted to the concrete only by the stiffener, a bearing plate is not necessarily provided.

"Effects of the Invention" As explained in detail above, according to the present invention, since the stiffener is provided inside the steel pipe so as to be continuous with the beam, the load applied to the beam can be directly transmitted to the concrete. Therefore, it is possible to prevent compressive force from being applied to the steel pipe, and it is possible to fully exhibit the confining effect of the steel pipe, thereby achieving the effect that the cross-sectional area of the column can be reduced. Also,
If the stiffener has a bearing plate at its lower part, the load of the beam can be transmitted to the concrete more effectively, and the above effect can be further enhanced.

In addition, at the center of the inside of the steel pipe, a pipe that extends in the axial direction of the steel pipe and through which a concrete pouring pipe for filling the concrete is inserted is installed only at the position where the steel pipe and the beam are joined. and arrange it,
Moreover, since the entire cross section of the internal space of the steel pipe is filled with the concrete, when filling the steel pipe with concrete using a concrete casting pipe, a concrete casting pipe such as a tremie pipe is passed inside the pipe. By this, the concrete pouring pipe can be always held at the axial center of the steel pipe by the pipe, and the concrete can be uniformly filled into the steel pipe, thereby greatly improving the reliability of the filled steel pipe concrete. be able to.

Moreover, since the pipe through which the concrete pouring pipe is inserted and which guides the concrete pouring pipe is provided only at the position where the steel pipe and the beam are joined, concrete can be filled from the bottom of the steel pipe through the concrete pouring pipe. In this process, concrete is not prevented from filling the entire space inside the steel pipe, and the inside of the pipe that serves as a guide for the concrete pouring pipe is also filled with concrete, which improves the reliability of filled steel pipe concrete. can be further improved.

Moreover, as mentioned above, simply by providing a pipe for inserting the concrete pouring pipe into the steel pipe, the steel pipe can be uniformly filled with concrete, resulting in a highly reliable filled steel pipe concrete column with low cost. It has an excellent effect that can be obtained at a low cost.

[Brief explanation of drawings]

1 to 6 are diagrams showing embodiments of the present invention. 1 to 4 show the first embodiment, and FIG. 1 is a plan cross-sectional view of the joint structure of this embodiment,
Figure 2 is an elevational sectional view taken from Figure 1, Figure 3 is an elevational sectional view when an unbonded layer is provided, and Figure 4 explains the method of constructing a pillar with a shingle structure in this example. FIG. FIGS. 5 and 6 are plan cross-sectional views showing the joint structures of the second and third embodiments, respectively. 7 and 8 show a conventional joint structure, with FIG. 7 being a plan sectional view and FIG. 8 being an elevational sectional view taken along the line shown in FIG. 7. 1... Filled steel pipe concrete column, 2... Steel pipe,
3...Concrete, 4...Beam, 5...Pipe, 6...
... Stiffener, 11... tube.

Claims (1)

[Scope of Claims] 1. A filled steel pipe concrete column formed by filling a steel pipe with concrete, the concrete extending in the axial direction of the steel pipe and filling the concrete in the inner center of the steel pipe. A pipe for inserting the pouring pipe is arranged corresponding only to the position where the steel pipe and the beam are joined, and a stiffener is installed between this pipe and the inner surface of the steel pipe so as to be continuous with the beam. 1. A filled steel pipe concrete column, characterized in that the concrete is filled over the entire cross section of the internal space of the steel pipe. 2. The filled steel pipe concrete column according to claim 1, wherein the stiffener has, at its lower end, a pressure plate having an area in a cross-sectional direction orthogonal to the axial direction of the steel pipe.