JP5655738B2 - Reinforced structure of square steel pipe column - Google Patents

Description

  The present invention relates to a reinforcing structure for a square steel pipe column, and more particularly to a reinforcing structure for a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column.

  Conventionally, as a reinforcing structure for circular steel pipe columns used for structures such as piers, steel towers, and buildings, the inner diameter larger than the outer diameter of the circular steel pipe columns is given to the part where local buckling is expected to occur. By arranging the reinforced steel pipe, a reinforced structure has been proposed that can suppress a sudden decrease in yield strength even if local buckling occurs in a circular steel pipe column (see, for example, Patent Document 1).

  In the conventional reinforcing structure described in Patent Document 1, a buckling mode in which a part of the compression edge protrudes radially outward is assumed as local buckling of a circular steel pipe column that receives axial compression and bending moment. Furthermore, lantern buckling due to the local buckling progressing in the circumferential direction is assumed. With respect to such a buckling mode, the conventional reinforcing structure surrounds the outer periphery of the circular steel pipe column and installs the reinforcing steel pipe through a predetermined interval, whereby local buckling occurs in the circular steel pipe column. Even if a part of the round steel pipe column protrudes outward, the progress of local buckling is suppressed by restraining the buckling deformation by bringing the inner surface of the reinforced steel pipe into contact with the protruding part, thereby rapidly In addition, it is configured to prevent a decrease in proof stress and to ensure deformation performance.

Japanese Patent No. 3522415

  By the way, the conventional reinforcing structure suppresses the progress of buckling deformation with respect to a buckling mode in which a part of a circular steel pipe column protrudes radially outward. In addition, local buckling or the like of members other than the circular steel pipe column is not assumed. For example, an optimal reinforcing structure cannot be obtained for a square steel pipe column having a buckling mode different from that of the circular steel pipe column. For this reason, development of the reinforcement structure which can suppress effectively the yield strength fall after the local buckling of a square steel pipe column was desired.

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to effectively suppress a decrease in yield strength and maintain deformation performance even after local buckling. An object of the present invention is to provide a reinforcing structure for a rectangular steel pipe column.

  The reinforcing structure of a rectangular steel pipe column of the present invention is a reinforcing structure of a rectangular steel pipe column for suppressing a decrease in yield strength after local buckling of the rectangular steel pipe column, and includes four side surfaces at predetermined positions in the longitudinal direction of the rectangular steel pipe column. It is provided with a restraining means that opposes through a gap from at least one of the outer surface side and the inner surface side, and when the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the side surface It is characterized in that the restraining means abuts and the deformation can be regulated.

  According to the present invention described above, when local buckling occurs in the rectangular steel pipe column and the side surface is deformed outward or inward, the deformation of the side surface is regulated by the restraining means, so that the buckling deformation proceeds. It is possible to suppress a sudden decrease in yield strength, and to maintain the deformation performance as a square steel pipe column by redistributing stress around the portion where local buckling has occurred. Here, the local buckling mode of the square steel pipe column is different from the one in which a part projects radially outward like the circular steel pipe column, and a pair of two side surfaces facing each other among the four side surfaces of the square steel pipe column are This is a buckling mode that protrudes outward and causes deformation such that another pair of opposing two side surfaces are recessed inward. Therefore, for a square steel pipe column, as in the present invention, by providing a restraining means facing each of the four side surfaces on at least one of the outer surface side and the inner surface side, the seat on at least two side surfaces is provided. Bending deformation can be constrained, and thereby a rapid decline in yield strength can be suppressed. In addition, since a fixed effect can be expected only by restraining deformation of the two side surfaces of the square steel pipe column, the restraining means may be provided on at least one of the outer surface side and the inner surface side of the four side surfaces. Obviously, if the buckling deformation on all four side surfaces is constrained by providing constraining means on both the inner surface sides, the effect of suppressing the decrease in yield strength can be enhanced.

  In this case, in the reinforcing structure of the square steel pipe column of the present invention, the restraining means includes an external square steel pipe that surrounds the square steel pipe column and has four restraining surfaces respectively facing the outer surface side of the four side surfaces. It may be configured.

  According to such a configuration, the four constraining surfaces of the outer rectangular steel pipe are respectively opposed to the outer surface sides of the four side surfaces of the rectangular steel tube column, so that two of the four side surfaces are buckled so as to protrude outward. When deformed, the restraining surfaces abut on these two side surfaces, respectively, and buckling deformation can be restricted. Since the other two side surfaces of the four side surfaces of the square steel pipe column are deformed so as to be recessed inward, these deformations cannot be restricted by the external square steel pipe, but the deformation of the two side surfaces projecting outward is not possible. By simply restricting, deformation of the other two side surfaces that continue through the corner portion is also suppressed, and a sudden decrease in yield strength as a square steel pipe column can be suppressed.

  Further, in the reinforcing structure of the square steel pipe column of the present invention, the restraining means is configured to have an internal square steel pipe or an internal circular steel pipe provided inside the square steel pipe column and facing the inner surface side of the four side surfaces. May be.

  Here, the internal square steel pipe may have four constraining surfaces along the inner surfaces of the four side surfaces of the square steel pipe column, and the four side surfaces and the inclined four surfaces and the corner portions (constraint corner portions). It may be provided to face the inner surfaces of the four side surfaces. Moreover, as an internal circular steel pipe, what is necessary is just to have an outer diameter dimension slightly smaller than the distance between the inner surfaces which a square steel pipe column opposes.

  According to such a configuration, the internal square steel pipe or the internal circular steel pipe is made to face the inner side of the four side surfaces of the square steel pipe column, thereby buckling and deforming so that two of the four side surfaces are recessed inward. At this time, the internal rectangular steel pipe or the internal circular steel pipe is brought into contact with these two side surfaces, respectively, so that buckling deformation can be regulated. Of the four side surfaces of the square steel pipe column, the other two side surfaces are deformed so as to protrude outward, so the deformation of these two side surfaces cannot be restricted by the internal square steel tube or the internal circular steel tube, but the inner side By simply restricting the deformation of the two side surfaces that are recessed, it is possible to suppress a sudden decrease in yield strength as a square steel pipe column.

Moreover, in the reinforcing structure of the rectangular steel pipe column of the present invention, the steel pipe provided outside or inside the rectangular steel pipe column has a yield strength of the steel pipe of σ _yr (N / mm ² ), and the length of the steel pipe in the axial direction. When the thickness is L (m), the width of the steel pipe in the direction parallel to the width of the square steel pipe column is D _r (m), and the plate thickness of the steel pipe is _tr (m), the following formula (1) May be satisfied. Here, β is the width of the square steel pipe column D _p (mm), the plate thickness of the square steel pipe column t _p (mm), the yield strength of the square steel pipe column σ _yp (N / mm ² ), When the Young's modulus of the square steel pipe column is E (N / mm ² ), it is represented by the following formula (2).

  As a result, it is possible to maximize the resistance ability of the rectangular steel pipe column against the out-of-plane deformation by the restraining means, effectively preventing the decrease in yield strength due to the out-of-plane deformation of the square steel pipe column, and The deformation performance can be effectively maintained.

  Further, in the reinforcing structure for a rectangular steel pipe column of the present invention, the restraining means includes four corner members provided along corners on the outer surface side of the rectangular steel tube column, and is fixed across these corner members. The four side surfaces may be configured to have four constraining surface materials facing each other.

  According to such a configuration, when the four constraining face members are respectively opposed to the outer surface sides of the four side surfaces of the square steel pipe column, when the buckling deformation is performed so that two of the four side surfaces protrude outward. In addition, the constraining face material abuts on each of these two side surfaces, and buckling deformation can be restricted. As described above, the deformation of the other two side surfaces recessed inwardly of the square steel pipe column cannot be restricted by the constraining face material, but the square steel pipe is only restricted by the deformation of the two side surfaces protruding outward. A sudden decline in proof stress as a pillar can be suppressed.

  Moreover, in the reinforcing structure for a rectangular steel pipe column of the present invention, the restraining means is provided at a pair of penetrating materials that penetrate two opposing side surfaces of the four side surfaces of the rectangular steel pipe column, and at the tip portions of these penetrating materials. It may be configured to have four tip members fixed and opposed to the four side surfaces.

  Here, the four tip members may be provided on the outer surface side with respect to the four side surfaces of the square steel pipe column, may be provided on the inner surface side, and further on the outer surface side and the inner surface side with respect to the four side surfaces. It may be provided in both.

  According to such a configuration, when the four tip members are respectively opposed to the four side surfaces of the rectangular steel pipe column, when two of the four side surfaces buckle and deform outward or inward, The tip member can be in contact with each side surface to restrict buckling deformation, or when the tip member is provided on both the outer surface side and the inner surface side with respect to the four side surfaces, the four side surfaces are on the outer side and the inner side. Even if buckling deformation occurs in either direction, the deformation can be regulated.

  In the reinforcing structure for a rectangular steel pipe column of the present invention, the restraining means includes an external steel pipe that surrounds the square steel pipe column and has four restraining surfaces respectively facing the outer surface sides of the four side surfaces, and It may be configured to have an inwardly convex curvature such that the surface is close to the four side surfaces at the center side and is far from the corner side.

According to such a configuration, the four constraining surfaces of the outer steel pipe are opposed to the outer surface sides of the four side surfaces of the rectangular steel pipe column, respectively, so that two of the four side surfaces buckle and deform outwardly. In doing so, the restraining surfaces abut against these two side surfaces, respectively, and the buckling deformation can be restricted. At this time, since the restraining surface has an inwardly convex curvature, the out-of-plane rigidity of the restraining surface can be increased by the arch effect, and the restraint surface is restrained when the side surface of the buckled deformed square steel pipe column comes into contact. The restraint effect can be enhanced by suppressing the deformation of the surface. As described above, the deformation of the other two side surfaces recessed inward of the square steel pipe column cannot be restricted by the external steel pipe, but the square steel pipe column is only restricted by the deformation of the two side surfaces protruding outward. As a result, it is possible to suppress a sudden decrease in yield strength.

  In the reinforcing structure of the rectangular steel pipe column according to the present invention, the restraining means is an outer circular steel pipe surrounding the rectangular steel pipe column, and protrudes from the inner surface of the outer circular steel pipe so as to face the outer surface side of the four side surfaces. You may comprise with four restraining protrusions.

  According to such a configuration, two of the four side surfaces protrude outward by causing the four constraining projections provided on the inner surface of the outer circular steel pipe to face the outer side of the four side surfaces of the square steel pipe column. Thus, when the buckling deformation occurs, the restraining protrusions abut against these two side surfaces, respectively, and the buckling deformation can be restricted. In this case, the restraint protrusion is provided on the outer circular steel pipe having a higher out-of-plane rigidity than the square formed of a plurality of planes, thereby enhancing the restraining effect when the side surface of the buckled deformed square steel pipe column contacts. Can do. As described above, the deformation of the other two side surfaces recessed inward of the square steel pipe column cannot be restricted by the restraining projection and the external circular steel pipe, but only the deformation of the two side surfaces protruding outward is restricted. Moreover, the rapid proof stress fall as a square steel pipe pillar can be suppressed.

Further, in the reinforcing structure of the rectangular steel pipe column of the present invention, the restraining means is a part of 0.1 D _p to 0.7 D _p from the material end of the rectangular steel pipe column with respect to the width dimension D of the rectangular steel pipe column. It is preferable that it is installed including the range.

According to this configuration, by installing the restraining means comprise a portion of a range of 0.1D _p ~0.7D _p from wood end of RHS Column, local buckling is likely to occur in the RHS Column Buckling deformation in the vicinity of the end (for example, in the vicinity of the column base) can be effectively restrained, and a decrease in the proof stress of the square steel pipe column can be suppressed.

  Further, in the reinforcing structure of the rectangular steel pipe column of the present invention, the restraining means includes the restraining means that comes into contact with the side surface when local buckling occurs in the square steel tube column and the side surface is deformed outward or inward. It is preferable that the clearance Δ between the contact portion of the means and the side surface of the square steel pipe column is 10 mm or less.

  According to such a configuration, it is possible to effectively prevent deterioration in yield strength at the initial buckling stage due to buckling deformation of the rectangular steel pipe column.

  According to the reinforcing structure for a rectangular steel pipe column of the present invention as described above, even when a rectangular steel pipe column having a buckling mode different from that of a circular steel pipe is used as an object, the outer surface side and the inner surface side of each of the four side surfaces are used. By providing the restraining means so as to face each other from at least one side, it is possible to restrain buckling deformation of at least two side surfaces, thereby suppressing a sudden decrease in yield strength of the square steel pipe column. Furthermore, even if it does not necessarily restrain the buckling deformation of all four side surfaces of the rectangular steel pipe column, it is possible to effectively suppress the decrease in the proof stress of the square steel tube column only by constraining the buckling deformation of at least two side surfaces. The deformation performance of the square steel pipe column can be maintained.

It is a plane sectional view showing the reinforcement structure of the square steel pipe pillar concerning a 1st embodiment of the present invention. It is a side view which shows the reinforcement structure of the square steel pipe pillar which concerns on 1st Embodiment. It is a plane sectional view showing an operation of a reinforcement structure of a square steel pipe pillar concerning a 1st embodiment. (A) is a perspective view which shows one form of the attachment structure of the external square steel pipe with respect to a square steel pipe column, (b) is the side surface sectional drawing. It is a plane sectional view showing the reinforcement structure of the square steel pipe pillar concerning a 2nd embodiment of the present invention. It is a perspective view which shows the reinforcement structure of the square steel pipe pillar which concerns on 2nd Embodiment. It is a plane sectional view showing the reinforcement structure of the square steel pipe pillar concerning a 3rd embodiment of the present invention. It is side surface sectional drawing which shows the reinforcement structure of the square steel pipe pillar which concerns on 3rd Embodiment. (A) is a plane sectional view showing the reinforcement structure of a square steel pipe pillar concerning a 4th embodiment of the present invention, and (b) is a plane sectional view showing the reinforcement structure of a square steel pipe pillar concerning the modification. It is side surface sectional drawing which shows the reinforcement structure of the square steel pipe pillar which concerns on embodiment of Fig.9 (a). (A) is a plane sectional view showing the reinforcement structure of a square steel pipe pillar concerning a 5th embodiment of the present invention, and (b) is a plane sectional view showing the reinforcement structure of a square steel pipe pillar concerning the modification. (A) is a plane sectional view showing dimensional conditions of a square steel pipe column and an internal circular steel pipe in FEM analysis performed under analysis condition I, and (b) is a side view thereof. It is a figure for demonstrating the load condition in the FEM analysis of the analysis condition I. It is a diagram showing the relationship between the thickness t _r of the total absorption energy and the internal circular steel tubes obtained from the analysis result of the analysis conditions I. (A) is a plane sectional view showing the deformation state of the rectangular steel pipe column and the internal circular steel pipe in the case of the analysis value a in FIG. 14, and (b) is the deformation of the square steel pipe column and the internal circular steel pipe in the case of the analysis value b. It is a plane sectional view showing a state. It is a figure which shows the relationship between the non-dimensional rotation angle (theta) / theta _p calculated | required from the analysis result of the analysis conditions I, and the non-dimensional bending moment M / M _p . It is a figure which shows the relationship between the maximum out-of-plane deformation force P which the internal circular steel pipe calculated | required from the analysis result of the analysis conditions I, and the normalized width-thickness ratio (beta) of a square steel pipe column. (A) is a figure which shows the bending moment distribution which an external square steel pipe receives by local buckling of a square steel pipe column, (b) is a figure which shows the bending moment distribution which an internal circular steel pipe receives by local buckling of a square steel pipe column. And (c) is a diagram showing a bending moment distribution received by the internal square steel pipe due to local buckling of the square steel pipe column, and (d) is a bending moment distribution of the external square steel pipe when the conditions are changed from (a). FIG. It is the figure which arranged the analysis result of analysis condition I by the relation between board thickness _tr / minimum board thickness _{tr (min)} which satisfies formula (6), and the rate of increase of total absorbed energy. (A) is a plane sectional view showing dimensional conditions of a square steel pipe column and an internal circular steel pipe in FEM analysis performed under analysis condition II, and (b) is a side view thereof. Obtained from the analysis result of the analysis condition II, which is a diagram showing the relationship between the deformation step and the non-dimensional maximum bending moment when the thickness t _p of the RHS Column is 22 mm. Obtained from the analysis result of the analysis condition II, which is a diagram showing the relationship between the deformation step and the non-dimensional maximum bending moment when the thickness t _p of the RHS Column is 17 mm. Obtained from the analysis result of the analysis condition II, which is a diagram showing the relationship between the deformation step and the non-dimensional maximum bending moment when the thickness t _p of the RHS Column is 13.4 mm.

  Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In the second and subsequent embodiments, the same constituent members as those described in the first embodiment and the constituent members having the same functions are denoted by the same reference numerals as those in the first embodiment. Those descriptions are omitted or simplified.

[First Embodiment]
1 and 2, the reinforcing structure for a rectangular steel pipe column according to the present invention includes a restraining means 2 provided at a column base portion which is a predetermined position in the longitudinal direction of the rectangular steel tube column 1. Even if local buckling occurs in the leg portion, the restraining means 2 regulates buckling deformation, thereby suppressing a decrease in the proof stress of the square steel pipe column 1 after local buckling and ensuring deformation performance. .

  The restraining means 2 of the present embodiment is constituted by an external square steel pipe 20 provided so as to surround the square steel pipe column 1, and the external square steel pipe 20 has a gap S on the outer surface 11 A side of each of the four side surfaces 11 of the square steel pipe column 1. It has four constraining surfaces 21 that are opposed to each other. Here, the external square steel pipe 20 may be a square steel pipe formed by welding and joining the four steel plates constituting the respective restraining surfaces 21 at the corners, or a steel material formed into a square tube shape by rolling or bending. It may be formed by welding and joining the edges.

  As shown in FIG. 3, the external square steel pipe 20 has a compression axial force and a bending moment, so that the column base portion of the square steel pipe column 1 is locally buckled, and two side surfaces 11 of the four side surfaces 11. Is deformed outward, the restraint surface 21 comes into contact with the outer surface 11A of these two side surfaces 11 so that buckling deformation of the square steel pipe column 1 can be regulated. Here, the buckling mode of the square steel pipe column 1 is such that a pair (two) of the four side surfaces 11 that face each other protrudes outward, and another pair of (two) side surfaces that face each other. Since this is a buckling mode in which 11 is deformed so as to be recessed inward, by restricting the buckling deformation of the two side surfaces 11 protruding outward by the external square steel pipe 20, the other 2 recessed inwardly. Even if the buckling deformation of the one side surface 11 is not restricted, these deformations can also be suppressed. Therefore, by restraining buckling deformation by the external square steel pipe 20, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to secure the deformation performance of the square steel pipe column 1.

  FIG. 4 is a view showing one form of a mounting structure for the square steel pipe column 1 of the external square steel pipe 20 constituting the restraining means 2 according to this embodiment, and FIG. 5 is a view showing another form of the mounting structure. .

  The mounting structure shown in FIG. 4 includes a support member 91 joined to the outer surface 11A of the square steel pipe column 1 by welding or the like, and the external square steel pipe 20 is supported on the support member 91 by supporting the external square steel pipe 20. Is attached to the square steel pipe column 1. The support member 91 is made of a metal material such as a steel material or a resin material, and is formed in various shapes such as an L shape.

  Thus, the attachment structure of the external square steel pipe 20 to the square steel pipe column 1 is not particularly limited.

[Second Embodiment]
As shown in FIGS. 5 and 6, the restraining means 2 of the present embodiment is provided so as to surround the square steel pipe column 1 and an angle member provided along the corner 12 on the outer surface 11 </ b> A side of the square steel pipe column 1. And four constraining face members 31 that are fixed across the corner members 30 and face each other on the outer surface 11A side of each of the four side faces 11 with a gap S therebetween. Has been.

  According to such a configuration, when the column side of the rectangular steel pipe column 1 is locally buckled and the two side surfaces 11 facing each other are deformed outward, the constraining surface material 31 is formed on the outer surface 11A of the two side surfaces 11. The buckling deformation of the square steel pipe column 1 can be regulated by abutting. Therefore, by restraining buckling deformation by the constraining face material 31, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to ensure the deformation performance of the square steel pipe column 1. Further, since the corner member 30 can increase the rigidity of the corner portion, when the side surface 11 of the square steel pipe column 1 is buckled and abutted against the constraining face material 31, the square steel pipe column 1 is further out of plane. Deformation can be effectively suppressed.

[Third Embodiment]
As shown in FIGS. 7 and 8, the restraining means 2 of the present embodiment includes a pair of penetrating members 40 that penetrate through through holes 13 formed in two opposing side surfaces of the four side surfaces 11 of the square steel pipe column 1. And four tip members 41 that are fixed to the tip portions of the respective penetrating materials 40 and face the outer surface 11A of each of the four side surfaces 11 with a gap S therebetween.

  Here, as the penetrating material 40, a steel bar having a thread at least at the tip can be used. However, the penetrating material 40 is not limited to a steel bar, and may be a member in which a bolt is joined to a long steel plate. Further, as the tip member 41, a nut that can be screwed into the thread of the penetrating material 40 can be used, and a nut with a collar having a collar facing the side surface 11 is preferable. It may be a steel plate welded and fixed to the tip.

  According to such a configuration, when the two side surfaces 11 facing each other due to the local buckling of the column base portion of the square steel pipe column 1 are deformed outward, the tip member 41 contacts the outer surface 11A of the two side surfaces 11. Since the buckling deformation of the rectangular steel pipe column 1 can be regulated in contact with each other, it is possible to suppress a sudden decrease in the proof stress of the rectangular steel pipe column 1 and to ensure the deformation performance of the rectangular steel pipe column 1.

[Fourth Embodiment]
As shown in FIG. 9A, the restraining means 2 of the present embodiment is configured to have an internal circular steel pipe 50 provided inside the square steel pipe column 1, and the internal circular steel pipe 50 is configured by the square steel pipe column 1. Each of the four side surfaces 11 has an outer peripheral surface 51 facing the inner surface 11B side with a gap S therebetween. That is, the outer diameter dimension of the inner circular steel pipe 50 is formed smaller than the inner dimension between the pair of inner surfaces 11B facing each other in the square steel pipe column 1, and the inner circular steel pipe 50 is loosely inserted inside the square steel pipe column 1. It is provided in the state.

  According to such an internal circular steel pipe 50, when the two side surfaces 11 facing each other due to local buckling of the column base portion of the square steel pipe column 1 are deformed inward, the internal circular shape is formed on the inner surface 11B of these two side surfaces 11. The outer peripheral surface 51 of the steel pipe 50 abuts so that buckling deformation of the square steel pipe column 1 can be regulated. Here, by restricting the buckling deformation of the two side surfaces 11 that are recessed inward by the internal circular steel pipe 50, it is possible to control these buckling deformations of the other two side surfaces 11 protruding outward without restricting these buckling deformations. Deformation can also be suppressed. Therefore, by restraining buckling deformation by the internal circular steel pipe 50, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to ensure the deformation performance of the square steel pipe column 1.

  Note that the restraining means 2 of the present embodiment is not limited to the internal circular steel pipe 50, but may be an internal square steel pipe 60 as shown in FIG. 9 (b). The internal square steel pipe 60 is a square steel pipe column 1. Each of the four side surfaces 11 has four corners 61 facing each other with a gap S on the inner surface 11B side. That is, the external dimension in the diagonal direction of the internal square steel pipe 60 is formed smaller than the internal dimension between the pair of inner surfaces 11B facing each other in the square steel pipe column 1, and the internal square steel pipe 60 is formed inside the square steel pipe column 1. It is provided in the loosely inserted state.

  Also with such an internal square steel pipe 60, when the two side surfaces 11 facing each other due to the local buckling of the column base portion of the square steel pipe column 1 are deformed inward, the internal square steel pipe is formed on the inner surface 11B of these two side surfaces 11. The 60 corner portions 61 come into contact with each other so that buckling deformation of the square steel pipe column 1 can be regulated. Therefore, by restraining buckling deformation by the internal square steel pipe 60, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to ensure the deformation performance of the square steel pipe column 1. Moreover, according to the internal circular steel pipe 50 and the internal square steel pipe 60 of this embodiment, since these restraining means 2 are not exposed to the outside of the square steel pipe column 1, the expansion of the external finish dimension of the square steel pipe column 1 is prevented. However, it can be reinforced from the inside which does not affect the appearance design.

  FIG. 10 is a view showing an embodiment of a structure for attaching the internal circular steel pipe 50 constituting the restraining means 2 according to the present embodiment to the square steel pipe column 1.

  The mounting structure shown in FIG. 10 includes a support member 91 joined to the inner surface 11B of the square steel pipe column 1 by welding or the like. By supporting the internal circular steel pipe 50 on the support member 91, the internal circular steel pipe 50 is provided. Is attached to the square steel pipe column 1. In addition, when attaching restraint means 2, such as the internal circular steel pipe 50, to the inner surface 11B of the square steel pipe column 1 as in this embodiment, the square steel pipe column 1 has four steel plates at the corners as shown in FIG. It is preferable that the steel pipe is formed by welding and joining to form a square steel pipe, or by welding and joining the edges of a steel material formed into a square tube shape by rolling or bending. As a result, it is possible to easily install the restraining means 2 inside the square steel pipe column 1 by assembling the square steel pipe column 1 after the restraining means 2 is previously installed inside the steel material to be the square steel pipe pillar 1. Become.

[Fifth Embodiment]
As shown in FIG. 11 (a), the restraining means 2 of the present embodiment is constituted by an external steel pipe 70 provided so as to surround the square steel pipe column 1, and the external steel pipe 70 has four side surfaces 11 of the square steel pipe column 1. Each constraining surface 71 has four constraining surfaces 71 facing each other with a gap S on the outer surface 11A side. The four constraining surfaces 71 are formed so as to be closest to the side surface 11 of the square steel pipe column 1 at the central portion in the width direction and have an inwardly convex curvature that moves away from the side surface 11 on the corner portion 12 side. A gap S is ensured between the inner peripheral surface 72 and the outer surface 11A in the central portion that is closest to.

  According to such an external steel pipe 70, when the two side surfaces 11 facing each other due to local buckling of the column base portion of the square steel pipe column 1 are deformed outward, the external steel pipe 70 is formed on the outer surface 11A of these two side surfaces 11. The inner peripheral surface 72 is in contact with each other so that buckling deformation of the rectangular steel pipe column 1 can be regulated. Therefore, by restraining buckling deformation by the external steel pipe 70, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to ensure the deformation performance of the square steel pipe column 1. Further, since the constraining surface 71 has an inwardly convex curvature, the out-of-plane rigidity of the constraining surface 71 can be increased by the arch effect, and the side surface 11 of the buckled deformed rectangular steel pipe column 1 comes into contact. In this case, the restraining effect can be enhanced by suppressing deformation of the restraining surface 71.

  The restraining means 2 of the present embodiment is not limited to the external steel pipe 70, and as shown in FIG. 11 (b), an external circular steel pipe 80 provided surrounding the square steel pipe column 1 and the inner surface of the external circular steel pipe 80 The four side surfaces 11 of the square steel pipe column 1 may be configured to have four restraining projections 81 facing each other through the gap S on the side of the outer surface 11A. That is, the inner circular dimension of the outer circular steel pipe 80 is formed larger than the outer dimension in the diagonal direction of the square steel pipe column 1, and the restraining protrusion 81 made of a steel plate is fixed to the inner peripheral surface of the outer circular steel pipe 80.

  Even with such a configuration, when the column side of the square steel pipe column 1 is locally buckled and the two side surfaces 11 facing each other are deformed outward, the restraining projection 81 abuts on the outer surface 11A of the two side surfaces 11. The buckling deformation of the square steel pipe column 1 can be regulated. Therefore, by restraining buckling deformation by the external circular steel pipe 80 and the restraining protrusion 81, it is possible to suppress a sudden decrease in the proof stress of the square steel pipe column 1 and to secure the deformation performance of the square steel pipe column 1. Further, by providing the restraining projection 81 on the inner peripheral surface of the outer circular steel pipe 80 having high out-of-plane rigidity, the restraining effect when the side surface 11 of the buckled deformed square steel pipe column 1 comes into contact can be enhanced. it can.

  Next, the attachment position with respect to the square steel pipe column 1 of the restraining means 2 which concerns on this invention is demonstrated.

Like the restraint means 2 according to the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment, when the restraint means 2 is configured to have a tubular body such as the external square steel pipe 20, As shown in FIG. 2, the restraining means 2 composed of a tubular body has a length dimension in the axial direction of 0.6 D _p or more with respect to the width dimension D _p (mm) of the square steel pipe column 1. is set to, and around the position of 0.4D _p from RHS column 1 of wood end 1a, it is preferable to be installed in axially opposite sides so as to include a range of 0.3D _p. In other words, the length L1 from the tube from RHS Column 1 of wood end 1a to the lower end portion 2a of the configured restraining means 2, each of the length L2 to the upper portion 2b 0.1 D _p below is preferably installed such that the 0.7D _p or more. By providing the restraining means 2 composed of a tubular body in such a range, it is possible to effectively suppress buckling deformation in the vicinity of the end of the square steel pipe column 1 where local buckling is likely to occur. Specifically, it is known that the local buckling waveform in the square steel pipe column 1 has a maximum out-of-plane deformation amount at a position of 0.4 Dp from the material end 1a of the square steel pipe column 1. position by covering an area of at least 0.3D in restraining means 2 composed of the tubular body at least 0.3D region and timber center of the _p in to the timber end 1a side mainly, buckling due to local buckling The effect of suppressing deformation can be enhanced.

Note that, when the restraining means 2 includes a pair of penetrating members 40 and a tip member 41 as in the reinforcing structure according to the third embodiment, the pair of penetrating members 40 and the tip member as the restraining means 2. 41, as shown in FIG. 8, if it is established comprise a portion ranging from the RHS column 1 of wood end 1a of 0.1D _p ~0.7D _p, effective buckling deformation of the above It is possible to exert an effect of suppressing the above.

  Next, preferable dimensional conditions of the restraining means 2 according to the present invention will be described.

The present inventor conducted FEM analysis under the analysis conditions as described below in order to study preferable dimensional conditions of the restraining means 2 according to the present invention. Hereinafter, the analysis condition will be described as analysis condition I.

  Under the analysis condition I, the deformation behavior of the rectangular steel pipe column 1 and the internal circular steel pipe 50 when the reinforcing structure of the rectangular steel pipe column 1 having the form shown in FIG.

The dimensional conditions of the square steel pipe column 1 and the internal circular steel pipe 50 were as shown in FIG. Changing 22 mm, 17 mm, and 13mm and conditions for the thickness t _p of RHS Column 1, it was analyzed by changing the various conditions for the thickness t _r of the inner steel tube 50. As the material conditions, the Young's modulus when BCP325 and STKR490 were used for each of the square steel pipe column 1 and the internal circular steel pipe 50 was set. The restraint conditions were set such that the material end 1 a of the square steel pipe column 1 was fixed to the ground surface 3. The load condition is that the square steel pipe column 1 is loaded with a compression axial force N (N) that is 0.3 times the yield axial force Ny (N), and the value and direction of the compression axial force are kept constant. The upper end portion 1b of the column 1 was set to be loaded so as to be bent and deformed. As shown in FIG. 13, the amount of bending deformation when bending deformation is shown in FIG. 13, where θ is the rotation angle of the central axis before bending deformation when the upper end portion 1a of the square steel pipe column 1 is bent. The deformation history as shown in FIG. In this variant history, when the bending moment at the RHS Column 1 of wood end 1a when the rotational angle θ was set to M, when allowed to load the bending load of the full plastic moment M _p to RHS Column 1 The maximum deformation amount of 2θ _p , 4θ _p , 6θ _p , and 8θ _p was set to be given twice in each order in order with respect to the rotation angle θ _p .

From the analysis result under the analysis condition I, the history area of the history curve obtained by organizing the relationship between the rotation angle θ and the bending moment M was integrated with the total loading history to obtain the total absorbed energy. Figure 14 is a diagram showing the relationship between the thickness t _r of the total absorbed energy and the internal steel tube 50.

Thus, the total absorption energy of RHS Column 1, improves with increasing thickness t _r of the inner steel tube 50, that tends to saturate when it exceeds a certain thickness newly finding . The value of the thickness t _r of the inner steel tube 50 when the total absorption energy is saturated, it has been found that tend to change according to the cross-sectional shape of the RHS Column 1. Hereinafter, the thickness t _p of RHS Column 1 is 22 mm, 17 mm, 13 mm out of the analysis values obtained under the respective conditions, the minimum thickness of the internal Tubular 50 when the total absorption energy is saturated It is called a saturated plate thickness value.

FIG. 15A is a plan sectional view showing a deformed state of the square steel pipe column 1 and the internal circular steel pipe 50 in the case of the analysis value a in FIG. 14, and FIG. 15B is a deformation state in the case of the analysis value b in FIG. FIG. Thus, if the plate thickness t _r of the inner steel tube 50 is smaller than the saturation plate thickness value, for plastic hinge will be formed within a circular steel tube 50 by out-of-plane deformation due to local buckling of RHS Column 1 in contrast, if the plate thickness t _r of the inner steel tube 50 is a saturated thickness value, plastic hinge has not been formed inside Tubular 50 by the RHS column 1 of plane deformation. The fact that a plastic hinge is formed in the internal circular steel pipe 50 means that the internal circular steel pipe 50 is not sufficiently resistant to the out-of-plane deformation of the square steel pipe column 1.

Further, from the analysis result under the analysis condition I, the non-dimensional rotation angle θ / θ _p obtained by dividing the rotation angle θ by the rotation angle θ _p and the non-dimensional bending moment obtained by dividing the bending moment M by the total plastic moment M _p. M / M _p was determined. FIG. 16 is a diagram showing the relationship between the non-dimensional rotation angle θ / θ _p and the non-dimensional bending moment M / M _p . Thus, when the plate thickness t _r of the inner steel tube 50 is compared with the case where the saturated plate thickness values if (solid line in the figure) and less than the saturated plate thickness values (dotted line in the figure), the plate thickness t _r is saturated When the thickness was smaller than the plate thickness value, the decrease in the yield strength after reaching the maximum yield strength was larger, and the amount of absorbed energy of the square steel pipe column 1 was smaller.

  From these facts, the reinforcing effect of the restraining means 2 that makes it possible to maximize the resistance ability of the restraining means 2 against out-of-plane deformation of the square steel pipe column 1 and to enable the reduction of the proof stress and the deformation performance of the square steel pipe pillar 1. In order to ensure sufficient, it is derived that it is necessary to set conditions such that the restraining means 2 does not form a plastic hinge due to out-of-plane deformation of the rectangular steel pipe column 1.

Here, the fact that the total energy absorbed RHS Column 1 in subsequent thickness t _r has exceeded the saturation thickness of the internal steel tube 50 is not increased, the thickness t _r is saturated thickness of the inner steel tube 50 If the value is a value, the out-of-plane deformation force P received by the internal circular steel pipe 50 from the square steel pipe column 1 is the maximum out-of-plane deformation force P that the internal circular steel pipe 50 can receive due to buckling deformation of the square steel pipe column 1. FIG. 17 is a diagram in which the maximum out-of-plane deformation force P is arranged in relation to the normalized width-thickness ratio β of the square steel pipe column 1. Here, the normalized width-thickness ratio β is the width of the square steel pipe column 1 is D _p (mm), the thickness of the square steel pipe column 1 is t _p (mm), and the yield strength of the square steel pipe column 1 is σ _yp ( N / mm ² ), when the Young's modulus of the square steel pipe column 1 is E (N / mm ² ), it is expressed by the following formula (2). More standardized width thickness ratio β is larger, will be the thickness t _p of the width B of a RHS Column 1 is smaller cross-sectional shape, so that local buckling is likely to occur.

As shown in FIG. 17, the larger the normalized width / thickness ratio β, the smaller the maximum out-of-plane deformation force P tends to be. It was newly discovered that there is a linear relationship. As a formula representing this linear relationship, a linear regression equation was obtained from the analysis value, and the following formula (3) was calculated. This maximum out-of-plane deformation force P is determined according to the dimensional condition of the square steel pipe column 1 and can be understood from the following formula (3), and does not depend on the form of the restraining means 2.
P = −348β + 622 (3)

Here, when the outer square steel pipe 20, the inner circular steel pipe 50, and the inner square steel pipe 60 as described in the first embodiment and the fourth embodiment are used as the restraining means 2, FIG. Consider the bending moment acting on each of the external square steel pipes 20 and the like when the force P acts on the positions shown in FIG. This bending moment shows a distribution as shown in FIGS. 18A to 18C, and the maximum bending moment M _max is PD _r / 8 at the position as shown in any case. Incidentally, D _r denotes the width D _r, such as an external RHS 20 in a direction parallel to the width D _p of RHS Column 1.

Then, the condition for the restraining means 2 such as the external square steel pipe 20 not to form the plastic hinge is that the maximum out-of-plane deformation force P calculated from the above equation (3) is applied to the restraining means 2 such as the external square steel pipe 20. The maximum bending moment M _max acting on the restraining means 2 when it acts will satisfy the following formula (4) in relation to the total plastic moment M _p .
M _max ≦ M _p (4)

Here, it is known that the total plastic moment M _p is derived from the following equation (5). Where Z _p is the plastic section modulus (mm ³ ) of the external square steel pipe 20 or the like constituting the restraining means 2, σ _yr is the yield strength (N / mm ² ), and L is the length in the tube axis direction a is (mm), t _r is the thickness (mm).

Then, the following equation (6) is derived by combining the above-described (3) to (5) and the maximum bending moment M _max = PD _r / 8.

Incidentally, in FIG. 18 (a), as a distribution of the bending moment of the external square steel pipe 20, the distribution when each side surface of the external square steel pipe 20 is considered to be connected so as to have rotational rigidity at the corner portion 22 is shown. Yes. When it is considered that each side surface of the external square steel pipe 20 is pin-connected at the corner portion 22, the distribution of the bending moment is as shown in FIG. 18 (d), and the maximum bending moment M _max is PD _r / 4 Considering this point, when the above (3) to (5) are combined, the following expression (6) ′ is derived as an expression that replaces the above expression (6).

Here, FIG. 19, the thickness t _r, such as an external circular steel tube 20 constituting the restraining means 2, values and RHS Column divided by the minimum thickness t _r satisfying the equation (6) described above _(min) It is the figure which arranged the analysis result by the relationship with the increase rate of 1 total absorbed energy. The increase rate of the total absorbed energy is obtained by dividing the total absorbed energy of the square steel pipe column 1 when the restraining means 2 is provided by the total absorbed energy of the square steel pipe column 1 when there is no restraining means 2. .

Thus, when the plate thickness t _r satisfying the equation (6) above, the total absorbed energy as compared to the condition there is no restraint means 2 can be confirmed that increased more than 1.2 times. Further, when 0.6 times the thickness t _r with respect to minimum thickness t _{r (min)} which satisfies the equation (6) described above, i.e., even if satisfying the equation (1) below, constraining It can be confirmed that the total absorbed energy can be increased by 1.1 times or more as compared with the condition without the means 2.

Based on the analysis result of the above analysis condition I, the following was derived as a preferable dimensional condition of the restraining means 2 according to the present invention. That is, when any one of the external square steel pipe 20, the internal circular steel pipe 50, and the internal square steel pipe 60 as described in the first embodiment and the fourth embodiment is used as the restraining means 2 according to the present invention, each steel pipe is used. 20, 50, 60 are preferably configured to satisfy the above-described formula (1). Thereby, it becomes possible to exhibit the excellent resistance performance by the steel pipes 20, 50, 60 against the out-of-plane deformation of the square steel pipe column 1, and while effectively preventing a decrease in the proof stress due to the out-of-plane deformation of the square steel pipe column 1. The deformation performance of the rectangular steel pipe column 1 can be effectively maintained. Further, from the viewpoint of maximizing the resistance ability of the steel pipes 20, 50, 60 against the out-of-plane deformation of the square steel pipe column 1, each steel pipe 20, 50, 60 satisfies the above-described formula (6). More preferably. Incidentally, when the restraining means 2 is constituted by the external square steel pipe 20, the right side of the above formula (1) is multiplied by 2 ^1/2 or the formula (6) ′ is satisfied. More preferably, this makes it possible to more effectively maintain the deformation performance of the square steel pipe column 1 while more effectively preventing a decrease in yield strength due to out-of-plane deformation of the square steel pipe column 1.

Incidentally, the above equation (1), (6), which defines the lower limit of the thickness t _r of the steel pipe 20, 50 and 60 constituting the restraining means 2, the upper limit value of the thickness t _r particularly Although not limited, from the viewpoint of exhibiting the effect stably with respect to the variation in the yield point of the steel material, the minimum thickness t _{r (min)} that satisfies the above-described formula (6) is 1.2. It is sufficient if a double plate thickness can be secured. Therefore, the plate thickness t _r, it is preferred to satisfy the equation (7) below, thereby, while exhibiting a stable effect on variation in the yield point of the steel material, it can be suppressed steel costs It becomes.

  Next, the clearance Δ (mm) between the restraining means 2 and the square steel pipe column 1 according to the present invention will be described. Note that the clearance Δ here refers to the contact portion 2c of the restraining means 2 that contacts the side surface 11 when local buckling occurs in the square steel pipe column 1 and the side surface 11 deforms outward or inward. And the width between the side surface 11 of the square steel pipe column 1.

  The inventor conducted FEM analysis under the analysis conditions as described below in order to study the preferable clearance Δ for the restraining means 2 according to the present invention. Hereinafter, the analysis condition will be described as analysis condition II.

  Similarly to the analysis condition I, the analysis condition II analyzes the deformation behavior of the square steel pipe column 1 and the internal circular steel pipe 50 when the reinforcing structure of the square steel pipe column 1 having the form shown in FIG. It was decided to.

The dimensions of the square steel pipe column 1 and the internal circular steel pipe 50 were as shown in FIG. Instead of 22mm, 17mm, and 13.4mm and conditions for the thickness t _p of RHS Column 1, was subjected to analysis in place of the various conditions for clearance Δ. Other material conditions, restraint conditions, and load conditions were the same as those of analysis condition I.

The dimensionless maximum bending moment obtained by dividing the maximum bending moment of the rectangular steel pipe column 1 at each step of the deformation history by the total plastic moment _Mp was obtained from the analysis result under the analysis condition II. 21 to 23 are diagrams showing the relationship between the dimensionless maximum bending moment and each step of the deformation history. Thus, it can be understood that the reinforcing effect of the internal circular steel pipe 50 improves as the clearance Δ decreases. In particular, if the clearance Δ is 10mm or less, strength degradation at the seat屈初life stage for buckling deformation of the RHS Column 1 regardless of the thickness t _p of RHS Column 1 was suppressed. This is because, when the clearance Δ is 10 mm or less, the internal circular steel pipe 50 comes into contact with the square steel pipe column 1 at the initial buckling stage of the square steel pipe column 1, and the buckling deformation restraining effect by the internal circular steel pipe 50 is exhibited at an early stage. It is thought that it was possible to make it. In addition, when the clearance Δ is 5 mm or less, the maximum proof stress at the initial stage of buckling against the buckling deformation of the square steel pipe column 1 is improved regardless of the plate thickness t _p of the square steel pipe column 1.

  Based on the above analysis results, in the present invention, the clearance Δ is preferably set to 10 mm or less. If the clearance Δ is 10 mm or less, it is possible to effectively prevent the yield strength deterioration at the initial buckling stage due to the buckling deformation of the square steel pipe column 1 by the restraining means 2. The clearance Δ is more preferably 5 mm or less. If the clearance Δ is 5 mm or less, it is possible to improve the maximum yield strength at the initial buckling stage with respect to the buckling deformation of the square steel pipe column 1. These effects can be exhibited in any of the first to fifth embodiments described above.

  In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention.

  For example, in each of the above embodiments, the restraining means 2 is provided on the column base portion of the square steel pipe column 1, but the longitudinal direction predetermined position of the square steel pipe column 1 provided with the restraining means 2 is not limited to the column base portion, It may be a column head or may be a column intermediate portion. Furthermore, the restraining means 2 may be provided at a plurality of locations including the column base portion and the column head portion of the square steel pipe column 1.

Also, the installation position of the restraining means 2, as in the above embodiment is not limited from the timber end of RHS Column 1 in the range of 0.1D _p ~0.7D _p, over the entire length of the RHS Column 1 The restraining means 2 may be provided continuously, or the restraining means 2 may be provided intermittently.

  In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the present invention has been illustrated and described with particular reference to particular embodiments, but it is not intended to depart from the technical idea and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations.

  Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

DESCRIPTION OF SYMBOLS 1 ... Square steel pipe column, 1a ... Material end, 1b ... Upper end part, 2 ... Restraint means, 2a ... Lower end part, 2b ... Upper end part, 2c ... Contact location, 3 ... Ground surface, 11 ... Side surface, 11A ... Outer surface, 11B ... Inner surface, 12 ... Corner, 20 ... External square steel pipe, 21 ... Restricted surface, 22 ... Corner, 30 ... Corner member, 31 ... Restrained surface material, 40 ... Penetration material, 41 ... End member, 50 ... Inner circle Steel pipe, 60 ... inner square steel pipe, 70 ... outer steel pipe, 71 ... restraint surface, 80 ... outer circular steel pipe, 81 ... restraint protrusion, 91 ... support member, S ... gap, Δ ... clearance.

Claims (13)

A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated .
The constraining means includes an internal square steel pipe or an internal circular steel pipe provided inside the square steel pipe column and opposed to the inner surface side of the four side surfaces, respectively. Construction. In the reinforcement structure of the square steel pipe column according to claim 1,
Reinforcing the square steel pipe column, wherein the restraining means comprises an external square steel pipe surrounding the square steel pipe column and having four constraining surfaces opposed to the outer surface side of the four side surfaces, respectively. Construction. A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When local buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated.
The restraining means includes an external square steel pipe that surrounds the square steel pipe column and has four restraining surfaces respectively facing the outer surface side of the four side surfaces ,
The steel pipe included in the restraining means has a yield strength of the steel pipe of σyr (N / mm ² ), a length of the steel pipe in the axial direction of L (mm), and the steel pipe in a direction parallel to the width of the square steel pipe column. The square steel pipe column reinforcing structure is characterized in that the following formula (1) is satisfied when the width of the steel pipe is Dr (mm) and the thickness of the steel pipe is tr (mm).

Where β is the width of the square steel pipe column Dp (mm), the plate thickness of the square steel pipe column tp (mm), the yield strength of the square steel pipe column σyp (N / mm ² ), the square steel pipe When the Young's modulus of the column is E (N / mm ² ), it is represented by the following formula (2).

In the reinforcement structure of the square steel pipe column according to claim 1 or 2 ,
The steel pipe included in the restraining means has a yield strength of the steel pipe of σyr (N / mm ² ), a length of the steel pipe in the axial direction of L (mm), and the steel pipe in a direction parallel to the width of the square steel pipe column. The square steel pipe column reinforcing structure is characterized in that the following formula (1) is satisfied when the width of the steel pipe is Dr (mm) and the thickness of the steel pipe is tr (mm).

Where β is the width of the square steel pipe column Dp (mm), the plate thickness of the square steel pipe column tp (mm), the yield strength of the square steel pipe column σyp (N / mm ² ), the square steel pipe When the Young's modulus of the column is E (N / mm ² ), it is represented by the following formula (2).

A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated .
The restraining means includes four corner members provided along corners on the outer surface side of the square steel pipe columns, and four restraining surface materials fixed between the corner members and facing the four side surfaces, respectively. A reinforcing structure for a rectangular steel pipe column, characterized by comprising: In the reinforcement structure of the square steel pipe column according to any one of claims 1 to 4 ,
The restraining means includes four corner members provided along corners on the outer surface side of the square steel pipe columns, and four restraining surface materials fixed between the corner members and facing the four side surfaces, respectively. A reinforcing structure for a rectangular steel pipe column, characterized by comprising: A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated .
The restraining means includes a pair of penetrating materials penetrating through two opposing side surfaces of the four side surfaces of the square steel pipe column, and four tip ends fixed to the tip portions of these penetrating materials and facing the four side surfaces, respectively. A reinforcing structure for a rectangular steel pipe column, characterized by comprising a member. A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated .
The restraining means includes an external steel pipe that surrounds the square steel pipe column and has four restraining surfaces facing the outer surface sides of the four side surfaces, the restraining surface being close to the four side surfaces at the center side and corners. A reinforcing structure for a square steel pipe column, characterized in that it is configured to have an inwardly convex curvature that becomes farther on the part side. In the reinforcement structure of the square steel pipe column according to any one of claims 1 to 4 ,
The restraining means includes an external steel pipe that surrounds the square steel pipe column and has four restraining surfaces facing the outer surface sides of the four side surfaces, the restraining surface being close to the four side surfaces at the center side and corners. A reinforcing structure for a square steel pipe column, characterized in that it is configured to have an inwardly convex curvature that becomes farther on the part side. A reinforcing structure of a square steel pipe column for suppressing a decrease in yield strength after local buckling of the square steel pipe column,
A constraining means that is opposed via a gap from at least one of the outer surface side and the inner surface side of the four side surfaces at a predetermined position in the longitudinal direction of the rectangular steel pipe column;
When the lateral buckling occurs in the square steel pipe column and the side surface is deformed outward or inward, the restraining means abuts on the side surface and the deformation can be regulated .
The restraining means includes an external circular steel pipe that surrounds the square steel pipe column, and four restraining protrusions that protrude from the inner surface of the outer circular steel pipe and face the outer surface of the four side surfaces. Reinforced structure of square steel pipe column characterized by that. In the reinforcement structure of the square steel pipe column according to any one of claims 1 to 4 ,
The restraining means includes an external circular steel pipe that surrounds the square steel pipe column, and four restraining protrusions that protrude from the inner surface of the outer circular steel pipe and face the outer surface of the four side surfaces. Reinforced structure of square steel pipe column characterized by that. In the reinforcement structure of the square steel pipe column according to any one of claims 1 to 11 ,
The square steel pipe column is characterized in that the restraining means is installed so as to include a part in a range of 0.1 Dp to 0.7 Dp from the material end of the square steel pipe column with respect to the width Dp of the square steel pipe column. Reinforcement structure. In the reinforcement structure of the square steel pipe column according to any one of claims 1 to 12 ,
The restraining means includes a contact portion of the restraining means that comes into contact with the side surface when local buckling occurs in the square steel tube column and the side surface is deformed outward or inward, and a side surface of the square steel tube column. The square steel pipe column reinforcing structure is characterized in that the clearance Δ is set to be 10 mm or less.

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