JPH0417265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a filled steel pipe concrete column structure used as a column of a building structure.

[Conventional technology]

Conventionally, a typical filled steel pipe concrete column has a structure in which a simple right cylindrical steel pipe that also serves as a formwork is erected vertically, and concrete is simply poured inside the steel pipe. This structure is a steel pipe filled with concrete, so the steel pipe and concrete are integrated as a whole. Conventionally, in the joint section where a beam is joined to a column made of filled steel pipe concrete, a stiffener ring is welded to the outer peripheral surface of the column as an auxiliary member to maintain the rigidity of the column, and the beam is attached to this stiffener ring. I'm trying to connect them.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional filled steel pipe concrete column structure, a beam is simply welded to the outer peripheral surface of the steel pipe, and the stress transmission between the steel pipe and the concrete depends on the adhesive strength of the joint. Therefore, the shearing force of the beam is transmitted as axial stress from the weld between the beam and the steel pipe to the steel pipe, and part of the axial stress transmitted to the steel pipe is transferred from the attachment surface of the steel pipe and concrete to the axis of the concrete. The force is also transmitted to the concrete. In addition, the moment of the beam is transmitted from the weld between the beam and the steel pipe to the steel pipe as in-plane shear stress, and part of the in-plane shear stress transmitted to the steel pipe is transferred from the steel pipe and concrete attachment surface to the concrete as shear stress. communicated.

In this way, in the conventional filled steel pipe concrete column structure, the force transmission path from the beam to the column twists and turns, and the transmission force is transmitted to the internal concrete from the bonding surface of the steel pipe and concrete. and depends on the adhesion strength of the concrete bonding surface.

Therefore, the steel pipes of the columns are subjected to axial stress, in-plane shear stress, and circumferential stress from the concrete, and are likely to become plastic due to the Mises yield condition.

Therefore, in conventional filled steel pipe concrete column structures, it is no longer possible to expect that the compressive strength of the concrete will increase due to the confining effect of the steel pipes compared to when the axial stress and in-plane shear stress are very small. As a result, the design safety factor had to be set to an excessively high value, resulting in the cross-sectional area of the columns being larger than necessary and the wall thickness of the steel pipes being thicker than necessary.

Incidentally, recently, the construction of skyscrapers has been rapidly increasing in urban areas. In Japan, in order to build high-rise buildings, column structures must be made of flexible structure for earthquake countermeasures. However, since the conventional filled steel pipe concrete column structure is a rigid column structure as described above, it is not preferable for the above-mentioned flexible structure super high-rise building.

This invention was made in view of the above circumstances, and by introducing a mechanical stress transmission path into the joint structure of columns and beams and ensuring the flatness of the concrete cross section of the columns, it is possible to connect the beams to the columns. Smooth, direct and clear transmission of force to the concrete part,
Furthermore, since the concrete part and the steel pipe part of the column are separated, they are made to behave mechanically as separate bodies, and the concrete part bears most of the force transmitted from the beam to the column, while the steel pipe part of the column The axial shearing force applied to the steel pipe is absorbed by the deformation of the deformation absorbing section formed in a portion of the steel pipe, preventing axial stress from occurring in the steel pipe, and the Mises yield condition equation is By reducing the axial stress inside to almost zero, the confining effect brought about by the steel pipe is enhanced, and the cross-sectional area of the column is reduced.
The purpose is to reduce the wall thickness of steel pipes.

[Means for solving problems]

This invention is a joint part where a column and a beam are joined,
Inside the steel pipe of the column, a pipe extending in the axial direction of the steel pipe near the approximate center of the steel pipe, and a stiffener continuous to the beam between the pipe and the inner surface of the steel pipe are provided, and further, A deformation absorbing part is formed in a part of the steel pipe of the column to prevent longitudinal stress from being generated in the steel pipe due to deformation of this part, and the steel pipe and the concrete filled in the steel pipe are formed. The feature is that an unbonding layer is provided at the interface between the steel pipe and concrete to prevent adhesion between the steel pipe and concrete.

In this invention, a communicating hole is provided through which the concrete filled in the pipe and the stiffener provided in the steel pipe of the joint portion is provided, and a deformation absorbing portion formed in a portion of the steel pipe is arranged in the axial direction of the steel pipe. At least a portion of the steel pipe is provided with one or more ring-shaped gaps that edge the steel pipe in the axial direction, or a deformation absorbing portion formed in a portion of the steel pipe extends in multiple rows in the circumferential direction of the steel pipe. A deformation absorbing portion formed in a part of the steel pipe may be a ring extending in the circumferential direction on at least a part of the outer circumferential surface of the steel pipe in the axial direction. The deformation absorbing portion formed in a portion of the steel pipe has a ring-shaped groove extending in the circumferential direction on the inner peripheral surface of at least a portion of the steel pipe in the axial direction. The deformation absorption part formed in a part of the steel pipe divides the steel pipe into two in the axial direction, and the end of the bisected steel pipe has an inner peripheral surface that is approximately flush with the inner circumference of the steel pipe. and a cylindrical deformation absorbing member is interposed to absorb axial deformation occurring in the steel pipe,
This deformation absorbing member is made by winding high-strength and high-rigidity fibers into a cylindrical shape, and binding and forming the fibers together with a solidifying material that has at least lower strength and lower rigidity than the steel pipe. The deformation absorbing portion formed in a portion is provided with a bulge formed by bending the steel pipe radially outward at a predetermined location in the longitudinal direction of the steel pipe, and this bulge causes deformation of the steel pipe in the axial direction. The unbonding treatment layer provided at the interface between the steel pipe and the concrete filled in the steel pipe can absorb paraffin, asphalt, oil, grease, petrolatum, etc. on the inner surface of the steel pipe. In order to achieve this, reinforcing members such as reinforcing bars are installed in the concrete filled in the steel pipe, and breath stress is introduced into the concrete filled in the steel pipe.
The concrete filled in the steel pipe is made of mortar, other hydraulic materials, or structural fillers that have sufficient compressive strength when compacted, such as earth, sand, metal powder, glass powder, plastic, and clay. It is desirable that the

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 is a diagram schematically showing an unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to the present invention. In the figure, reference numeral 1 denotes a column (hereinafter simply referred to as a "column") of an unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing section, and the columns 1, 1, ... have beams 2, 2, ... However, Shiguchi part 3,
3,... are connected. Also, pillar 1,
Near the approximate middle part of the floors of columns 1, 1, ... (recurved surface of moment), the axial deformation of the steel pipes is absorbed by the 4 sections of the steel pipes of columns 1, 1, ..., so that the axial deformation of the steel pipes is Deformation absorbing portions 5, 5, . . . are formed to prevent stress from occurring. Furthermore, the insides of the steel pipes 4 of the columns 1, 1, ... are filled with concrete 6, which will be described later, and the interface between the steel pipes 4 and the concrete 6 is filled with a material that prevents adhesion between the steel pipes 4 and the concrete 6, which will be described later. An unbonding treatment layer 7 is provided for this purpose. This unbonding layer 7
The inner surface of the steel pipe 4 is coated with paraffin, asphalt,
It is coated with a separating material such as oil, grease, or vaseline.

Next, using FIGS. 2 and 3,
That is, to explain the structure of the part where the beam 2 is joined, a pipe 8 with a circular cross section and a length approximately equal to the beam size of the beam 2 is arranged in the inner center of the steel pipe 4 along the axial direction of the steel pipe 4. has been done. The inner diameter of this pipe 8 is set to be large enough to allow insertion of a tremie pipe used for filling concrete 6 into the steel pipe 4, as will be described later. Further, stiffeners 9, 9, . . . are provided between the pipe 8 and the inner surface of the steel pipe 4. These stiffeners 9, 9, . are connected to each other via.

The tube 8 disposed at the center of the steel tube 4 may have a rectangular cross section large enough to allow the tremie tube to be inserted therethrough, as shown in FIG.

Here, using FIG. 6, a concrete 6
I will briefly explain how to fill it. First, the steel pipes 4, 4... are erected at predetermined positions, and the beams 2, 2... are joined to them. Then, the tremie pipe 10 is inserted into the steel pipe 4 from the top of the steel pipe 4, and the tremie pipe 10 is inserted into the steel pipe 4. Pass it through the tube 8 located in the center. and,
Concrete 6 is press-fitted into the steel pipe 2 through the tremie pipe 10, and the tremie pipe 10 is gradually pulled up while keeping the tip (lower end) of the tremie pipe 10 always buried in the concrete 6. As a result, the press-fitted concrete 6 gradually moves into the steel pipe 4.
The liquid rises inside the steel pipe 4 and is fully filled to every corner of the steel pipe 4. According to this method, the tremie tube 1
Since the concrete 6 can be placed at the optimum position at the center of the steel pipe 4, the concrete 6 can be evenly press-fitted into the steel pipe 4, and uneven placement will not occur. At the joint part, since sufficient clearance is secured inside the steel pipe 4, the rise of the concrete 6 is not hindered. Further, for the unbonding treatment layer 7, a separation material is applied to the inner surface of the steel pipe 4 before the concrete 6 is press-fitted.

In addition, in the joint part 3, as shown in FIG. 5, in order to further improve the filling of the concrete 6, a pipe 8 and stiffeners 9, 9, . . . A communication hole 11 through which concrete passes may be formed in the side part of the plate in the thickness direction of the plate.

Next, using FIG. 7, the deformation absorbing portion 5, which is formed in the steel pipe 4 near the approximate center of the column 1,
The configuration of 5,... will be explained.

At predetermined locations in the axial direction of the steel pipe 4, four stages of ring-shaped gaps 12 are formed to edge the steel pipe 4 in the axial direction. This portion constitutes a deformation absorbing portion 5 that absorbs axial deformation occurring in the steel pipe 4. Each ring-shaped gap 12 of the deformation absorbing portion 5 is filled with a flexible material 13 so that its inner surface is flush with the inner surface of the steel pipe 4. As the flexible material 13, asphalt, rubber, lead, aluminum, etc., which are softer than the steel pipe 4, can be used. Further, an unbonding treatment layer 7 is provided between the steel pipe 4 and the concrete 6.

Next, an explanation will be given of the effect when a force is applied from the beam 2 to the column 1 of the unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion configured as described above.

1 to 3, the shearing force acting mainly on the web 2a of the beam 2 is transmitted to the stiffener 9 and the pipe 8 via the steel pipe 4. The shear force transmitted to the stiffener 9 and the pipe is transmitted as an axial force to the concrete 6 containing them. In this way, the shearing force of the beam 2 is applied to the web 2 through the steel pipe 4.
It is directly transmitted to the concrete 6 through the stiffener 9 and the pipe 8 which are mechanically connected to the concrete 6, that is, through the mechanical transmission path. Therefore, the steel pipe 4 is not subjected to much shearing force from the beam 2. Furthermore, even if the steel pipe 4 receives part of the shearing force from the beam 2, since the unbonding treatment layer 7 is provided between the steel pipe 4 and the concrete 6, the steel pipe 4 and the concrete 6 will not be unbonded ( They are in a separated state and can move relative to each other in the axial direction of the column 1.

Here, when the concrete 6 is compressed and exceeds a predetermined strength, the concrete 6 causes strain in the axial direction as well as sudden transverse strain in the radial direction. However, the steel pipe 4 is not restrained by the concrete 6 in the axial direction at all, and the strain in the axial direction of the steel pipe 4 is absorbed by the deformation of the deformation absorbing part 5, and the strain in the axial direction between the upper and lower parts of the deformation absorbing part 5 is absorbed. Stress transmission is eliminated, and almost no axial stress is generated in the steel pipe 4. Therefore, when the Mises yield condition is applied, the strength against the stress in the circumferential direction generated in the steel pipe 4 due to the transverse strain of the concrete 6 increases, and the confining effect given to the concrete 6 can be enhanced. Therefore, this column 1 is guaranteed to have a much higher compressive strength than the conventional column, and the design safety factor can be appropriately set. In addition, since the cross-sectional area of the pillar 1 is often determined by the cross-section of the joint part 3, it is possible to make the cross-section of the pillar 1 smaller as a result, or to reduce the wall thickness of the steel pipe 4. is possible.

Next, a second embodiment will be described using FIGS. 1 to 6 and FIG. 8. In the embodiment shown in FIG. 8, the deformation absorbing portion 5 of the column 1 of the first embodiment is configured as follows. A plurality of long holes 14, 14, ... are arranged in a staggered manner in the circumferential direction of the steel pipe 4, and the upper and lower long holes 14, 14,
The end portions of... are wrapped by the same size in the circumferential direction, and the portions where the elongated holes 14, 14,... are not formed are continuous in the circumferential direction. Further, an unbonding treatment layer 7 is provided on the inner peripheral surface of the steel pipe 4. Other configurations include the first
This embodiment is exactly the same as the embodiment, and the same components are given the same reference numerals.

Therefore, in this second embodiment as well, the strain in the axial direction of the steel pipe 4 is absorbed by the deformation of the deformation absorbing portion 5, and the same actions and effects as in the first embodiment can be obtained. can.

Next, a third embodiment will be described using FIGS. 1 to 6 and FIG. 9. The embodiment shown in FIG. 9 has a ring-shaped groove 1 extending in the circumferential direction of the steel pipe 4 in the deformation absorbing portion 5 of the column 1 of the first embodiment.
5 was formed. In the circumferential direction of the steel pipe 4,
Four stages of ring-shaped grooves 15, 15, . The width and number of stages of the ring-shaped groove 15 of the deformation absorbing section 5 are set appropriately according to the design conditions, and the thickness of the thin part of the ring-shaped groove 15 is determined by assembling the steel pipe 4 on the upper floor. The structure is set so that it has sufficient strength during erection and strength as a formwork when pouring concrete inside the steel pipe 4. Further, an unbonding treatment layer 7 is provided on the inner peripheral surface of the steel pipe 4. The rest of the structure is completely the same as that of the first embodiment, and the same components are given the same reference numerals.

Therefore, also in this third embodiment, the strain in the axial direction of the steel pipe 4 is absorbed by the deformation of the deformation absorbing portion 5, and the transmission of axial stress between the upper and lower portions of the deformation absorbing portion 5 is eliminated. Almost no axial stress is generated in the steel pipe 4, and the same functions and effects as in the first embodiment can be obtained.

Next, a fourth embodiment will be described using FIGS. 1 to 6 and FIG. 10. In the embodiment shown in FIG. 10, a ring-shaped groove 16 extending in the circumferential direction is formed on the inner peripheral surface of the steel pipe 4 in the deformation absorbing portion 5 of the column 1 of the first embodiment. be. Four stages of ring-shaped grooves 16 extending in the circumferential direction of the steel pipe 4 are formed on the inner circumferential surface of the steel pipe 4, and this portion constitutes a deformation absorbing portion 5 that absorbs axial deformation occurring in the steel pipe 4. .

The thickness of the thin wall portion of the ring-shaped groove 16 of the deformation absorbing portion 5 is determined based on the strength at the time of erection when the steel pipe 4 is assembled to the upper layer, and the thickness of the formwork when pouring concrete inside the steel pipe 4. Set it so that it has strength. Further, an unbonding treatment layer 7 is provided on the inner circumferential surface of the steel pipe 4, and a separating material is also filled in the ring-shaped groove 16 as a flexible material. The rest of the structure is completely the same as that of the first embodiment, and the same components are given the same reference numerals.

Therefore, in this fourth embodiment as well, the strain in the axial direction of the steel pipe 4 is absorbed by early buckling of the thin wall portion of the ring-shaped groove 16 of the deformation absorbing portion 5, and There is no transmission of axial stress between the upper and lower parts, almost no axial stress is generated in the steel pipe 4, and the same functions and effects as in the first embodiment can be obtained.

Next, a fifth embodiment will be explained using FIGS. 1 to 6 and FIGS. 11 and 12. 11th
In the embodiment shown in the figure, the deformation absorbing portion 5 of the column 1 of the first embodiment is configured as follows. The steel pipe 4 is axially divided into two parts at a predetermined point in the axial direction, and the end portions of the divided steel pipe 4 have an inner diameter that is approximately the same as the inner diameter of the steel pipe 4, and a structure that prevents axial deformation that occurs in the steel pipe 4. Absorbing cylindrical deformation absorbing member 1
7 is interposed. The deformation absorbing member 17
As shown in FIG. 2, fibers 18 having high strength and high rigidity are closely wound into a cylindrical shape, and are coated with a solidifying material 19 having at least lower strength and lower rigidity than the steel pipe 4, such as rubber, vinyl chloride, or
It is made of PEEK resin, etc., and is integrally bound and molded to prevent it from unraveling. Therefore, although it deforms in the axial direction, it hardly deforms in the circumferential or radial directions, and has high strength and rigidity.

The deformation absorbing portion 5 is connected to the steel pipe 4 by step-shaped notches on the outer circumferential surface of the upper and lower ends of the deformation absorbing portion 5, and step-like notches on the inner circumferential surface of the end portion of the steel pipe 4. A steel pipe 4 and a deformation absorbing member 17 are installed in the missing part.
This is achieved by inserting each end of the In this case, the thickness and length of the deformation absorbing member 17 should be set in accordance with the strength of the steel pipe 4 and the magnitude of deformation occurring in the steel pipe 4. Further, an unbonding treatment layer 7 is provided on the inner peripheral surface of the steel pipe 4. The rest of the structure is completely the same as that of the first embodiment, and the same components are given the same reference numerals.

Therefore, in this fifth embodiment as well, the axial strain that occurs in the steel pipe 4 is absorbed by the deformation absorbing part 5, and the transmission of axial stress between the upper and lower parts of the deformation absorbing part 5 is eliminated, and the steel pipe 4 is Almost no axial stress is generated, and the same effect as in the first embodiment is achieved.
effect can be obtained.

Next, a sixth embodiment will be described using FIGS. 1 to 6 and FIG. 13. In the embodiment shown in these figures, the deformation absorbing portion 5 of the column 1 of the first embodiment is configured as follows. At a predetermined location in the longitudinal direction of the steel pipe 4, a bulge 20 is formed by bending and deforming the steel pipe radially outward.
is formed. This bulging portion 20 absorbs axial deformation that occurs in the steel pipe 4 due to bending of the iron plate. A flexible material 22 is placed inside the bulge 20 to prevent the concrete 6 from entering the bulge inner space 21.
is packed. Further, an unbonding treatment layer 7 is provided on the inner peripheral surface of the steel pipe 4. The rest of the structure is completely the same as that of the first embodiment, and the same components are given the same reference numerals.

Therefore, the axial strain that occurs in the steel pipe 4 is absorbed by the bulge 20, and no axial stress is transmitted between the upper and lower parts of the bulge 20, and almost no axial stress is generated in the steel pipe 4. It is possible to obtain the same functions and effects as those of the first embodiment described above.

Furthermore, the column 1 of the unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion in the first to sixth embodiments described above can be used as a column of a flexible structure because the cross-sectional area of the column can be reduced. It is possible. Here, skyscrapers are representative of flexible structures. When a skyscraper building vibrates due to an earthquake or the like, it bends to absorb the vibration and prevent the building from collapsing. In such high-rise buildings, the conventional filled steel pipe concrete column structure increases the cross-sectional area of the column, resulting in a rigid structure, which is undesirable. Therefore, the unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion in this embodiment is suitable for application to super high-rise buildings.

In each of the above embodiments, the steel pipe 4 was filled with concrete 6, but instead of concrete, mortar, other hydraulic materials, soil,
sand, metal powder, glass powder, plastic,
Structural fillers such as clay, which have a high compressive strength when consolidated, may be used instead. Furthermore, it is optional to increase the strength of the concrete by inserting reinforcing bars into the concrete 6 or arranging prestressed steel. Further, in the above embodiment, the case where the column 1 has a circular cross section is shown, but the present invention can of course be applied to cases where the cross section is octagonal or other polygonal shapes.

[Effects of the Invention] As described above, the unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to the present invention has a structure in which the inside of the steel pipe of the column is , a pipe extending in the axial direction of the steel pipe is provided near the center of the steel pipe, a stiffener continuous to the beam is provided between the pipe and the inner surface of the steel pipe, and a stiffener is provided in a portion of the steel pipe of the column. ,
In addition to forming a deformation absorbing part to prevent axial stress from being generated in the steel pipe due to deformation of this part, the steel pipe and the concrete filled in the steel pipe are Since it has an unbond treatment layer to eliminate adhesion to the concrete, it ensures that the concrete cross section of the column maintains its flatness, and the majority of the force transmitted from the beam to the column is transferred smoothly and directly to the concrete cross section of the column. Furthermore, since the concrete part and steel pipe part of the column are separated, they behave as mechanically separate bodies, and most of the force transmitted from the beam to the column is borne by the concrete part. At the same time, the axial shearing force applied to the steel pipe part of the column is absorbed by the deformation of the deformation absorbing part formed in a part of the steel pipe, preventing axial stress from occurring in the steel pipe. However, by applying the Mises yield condition, it is possible to increase the allowable value of stress applied in the circumferential direction of the steel pipe, and it is fully expected that the compressive strength of concrete will increase due to the confining effect brought about by the steel pipe. This makes it possible to reduce the cross-sectional area of columns and the wall thickness of steel pipes.

[Brief explanation of drawings]

1 to 13 are diagrams showing embodiments of the present invention. Fig. 1 is a front view showing a schematic outline of the invention, Fig. 2 is an elevational cross-sectional view showing the joint section of Fig. 1, Fig. 3 is a - sectional view of Fig. 2, and Fig. 4 is Fig. 3. Fig. 5 is an elevational sectional view when a communicating hole is formed between the pipe and the stiffener shown in Fig. 2, and Fig. 6 is a cross-sectional view when the cross section of the pipe is square. FIG. 7 is an elevational sectional view showing the filling method, and FIG. 7 is a partial sectional view of the deformation absorbing part, showing the first embodiment. FIG. 8 is a view showing the second embodiment, and is a partial sectional view of the deformation absorbing part. FIG. 9 is a partial cross-sectional view of the deformation absorbing part, showing the third embodiment, and FIG. 10 is a partial cross-sectional view of the deformation absorbing part, showing the fourth embodiment. 11 are diagrams showing the fifth embodiment, and FIG. 12 is a perspective view of the deformation absorbing member in FIG. 11, and FIG.
FIG. 3 is a diagram showing the sixth embodiment, and is a vertical sectional view of the deformation absorbing section. 1... Column (column with a filled steel pipe concrete column structure having a stiffener and a deformation absorption part), 2... Beam, 3
... Connection part, 4 ... Steel pipe, 5 ... Deformation absorption part, 6
...Concrete, 7...Unbonded treatment layer, 8
... tube, 9, ... stiffener, 10 ... tremie tube, 11 ... communication hole, 12 ... ring-shaped gap, 1
3... Soft material, 14... Elongated hole, 15, 16... Ring-shaped groove, 17... Deformation absorbing member, 18... Fiber, 19,... Solidifying material, 20... Swelling part.

Claims (1)

[Scope of Claims] 1. In a filled steel pipe concrete column structure, at the joint part where the column and the beam are joined, inside the steel pipe of the column, in the vicinity of the approximate center of the steel pipe, in the axial direction of the steel pipe. An extending pipe and a stiffener continuous to the beam are provided between the pipe and the inner surface of the steel pipe, and further,
A deformation absorbing part is formed in a part of the steel pipe of the column to prevent axial stress from being generated in the steel pipe due to deformation of this part, and the steel pipe and the concrete filled in the steel pipe are formed. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing part, characterized in that an unbonding treatment layer is provided at the interface between the steel pipe and the concrete to eliminate adhesion between the steel pipe and the concrete. 2. The stiffener and deformation absorbing portion according to claim 1, wherein a communicating hole through which the concrete to be filled passes is provided in the pipe and the stiffener provided in the steel pipe of the joint portion. Unbonded type filled steel pipe concrete column structure with. 3. A patent characterized in that the deformation absorbing portion formed in a portion of the steel pipe is provided with one or more ring-shaped gaps that edge the steel pipe in the axial direction in at least a portion of the steel pipe in the axial direction. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to claim 1 or 2. 4. Claim 1 or 4, wherein the deformation absorbing portion formed in a portion of the steel pipe is provided with a plurality of long holes extending in plural rows in the circumferential direction of the steel pipe. An unbonded filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to item 2. 5. A patent characterized in that the deformation absorbing portion formed in a portion of the steel pipe has a ring-shaped groove extending in the circumferential direction formed on at least a portion of the outer peripheral surface of the steel pipe in the axial direction. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to claim 1 or 2. 6. A patent claim characterized in that the deformation absorbing portion formed in a portion of the steel pipe is a ring-shaped groove extending in the circumferential direction on the inner circumferential surface of at least a portion of the steel pipe in the axial direction. An unbonded filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to item 1 or 2. 7 The deformation absorbing portion formed in a portion of the steel pipe divides the steel pipe into two in the axial direction, and the end of the bisected steel pipe has an inner circumferential surface that is substantially flush with the inner circumferential surface of the steel pipe, A cylindrical deformation absorbing member is interposed to absorb axial deformation occurring in the steel pipe,
This deformation absorbing member is characterized in that fibers having high strength and high rigidity are wound into a cylindrical shape, and the fibers are integrally bound and molded with a solidifying material having at least lower strength and lower rigidity than steel pipes. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to claim 1 or 2. 8 The deformation absorbing portion formed in a portion of the steel pipe is provided with a bulge formed by bending and deforming the steel pipe radially outward at a predetermined location in the longitudinal direction of the steel pipe, and the bulge is formed at a predetermined location in the longitudinal direction of the steel pipe. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to claim 1 or 2, wherein the structure is configured to be able to absorb deformation in the axial direction. 9. The unbonding treatment layer provided at the interface between the steel pipe and the concrete filled in the steel pipe is characterized by applying a separating material such as paraffin, asphalt, oil, grease, petrolatum, etc. to the inner surface of the steel pipe. An unbonded type filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to claims 1 to 8. 10. An unbonded filled steel pipe having a stiffener and a deformation absorbing portion according to claims 1 to 9, wherein reinforcing members such as reinforcing bars are provided in the concrete filled in the steel pipe. Concrete column structure. 11. An unbonded filled steel pipe concrete column structure having a stiffener and a deformation absorbing portion according to any one of claims 1 to 9, characterized in that a brace stress is introduced into the concrete filled in the steel pipe. 12 The concrete filled in the steel pipe is
mortar, other hydraulic materials, or soil,
The stiffener according to any one of claims 1 to 9, characterized in that it is a structural filler such as sand, metal powder, glass powder, plastic, clay, etc. that has sufficient compressive strength when compacted. An unbonded filled steel pipe concrete column structure with a deformation absorption section and a deformation absorbing section.