JP2005240426A - Erection structure for steel-pipe column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an erection structure which facilitates the injection of a filler, wherein the filler can properly spread, and which can sufficiently ensure erection strength of a steel-pipe column. <P>SOLUTION: In this erection structure for the steel-pipe column, wherein the steel-pipe column 2 is inserted into a vertical hole 20 provided in a concrete foundation 1 etc., so that the filler 4 can be infilled, a cross-sectional area of a base part 31 of a newly constructed steel-pipe column 3, which is to be inserted into the vertical hole 20, is set smaller than that of an above-ground part 32; the base part 31 and the above-ground part 32 are made to continue into each other via a stepped part 33; and an overhanging part 37 is provided near the stepped part 33, so that the column 3 can be erected in a state wherein the overhanging part 37 abuts on a surface of the concrete foundation 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a standing structure of steel pipe columns including pillars such as street lamps, road signs, and flagpoles.

  Steel pipe columns having a hollow circular cross section or polygonal cross section are also widely used in structures such as street lamps, road signs, flag poles, and steel structure structures. This type of steel pipe column is usually erected by embedding a base portion of the steel pipe column in a concrete foundation provided in the ground such as a roadside.

  When such a steel pipe is corroded near the root due to aging, or damaged by a traffic accident or the like, it must be rebuilt. When the entire steel pipe column with the base embedded in the concrete foundation is to be rebuilt, the concrete foundation must be crushed and removed, the existing steel pipe column removed, the new steel pipe column installed, and the concrete placed and cured again. In addition, troublesome labor and a long construction period are required, resulting in great inconvenience in road use and a large amount of concrete pieces as waste materials.

  Therefore, as a simple rebuilding method, an existing steel pipe column is cut from the surface of the concrete foundation while leaving a predetermined dimension, and a new steel pipe column is inserted on the outside (for example, Patent Document 1), or a concrete foundation is appropriately used. A method of crushing and removing the existing steel pipe column, cutting the existing steel pipe column, connecting the new steel pipe column to the existing steel pipe column by welding or the like, and then solidifying the connecting portion again with concrete (for example, Patent Document 2) Proposed.

  However, the new steel pipe columns that are erected by the rebuilding method as described above are not retained in the concrete foundation for a sufficient depth, so the rebuilding is performed against bending moments acting on the base of the steel pipe columns. There is a possibility that the same strength as before cannot be secured.

Accordingly, the present applicant has proposed and put to practical use a steel pipe column rebuilding method as shown in FIG. 4 in Japanese Patent Application No. 2003-190266 filed earlier. In this rebuilding method, an existing steel pipe column whose base 21 is solidified by the concrete foundation 1 is cut at the surface of the concrete foundation 1, and a new steel pipe column 3 is formed in the hollow portion of the base 21 left in the concrete foundation 1. Is inserted, and then the filler 4 is injected into the hollow portion and hardened. According to this rebuilding method, the base 31 of the new steel pipe column 3 can be hardened to a sufficient depth without crushing and removing the concrete foundation 1, so that it is relatively strong in combination with shortening the construction period and reducing waste materials. It is possible to realize the rebuilding of steel pipe columns with excellent resistance.
JP-A-57-174572 JP 2001-132272 A

  Since the new steel pipe column erected by the rebuilding method shown in FIG. 4 is inserted into the base part of the cut existing steel pipe column, at least the base part of the new steel pipe column is smaller in diameter than the existing steel pipe column. It must be. In the first place, steel pipe columns used for street lights, road signs, etc. are usually designed with a minimum cross-section required for wind loads, etc., and as a result, the cross-sectional dimensions are usually much smaller than the height. It is. Among external forces acting on steel pipe columns, the bending moment is the most important cross-section design factor, and the bending moment increases as it approaches the ground. Therefore, if the height of the new steel pipe column and the weight of the equipment attached to the upper part are about the same as the existing steel pipe column, the diameter of the base of the new steel pipe column is approximated to the diameter of the existing steel pipe column as much as possible, and A device that reinforces the strength to the same level as before rebuilding is required.

  However, if an attempt is made to approximate the diameters of the bases of old and new steel pipe columns, the gap for injecting the filler becomes very narrow, making it difficult to inject the filler. When the existing steel pipe column is a tapered pole whose diameter is reduced upward from the base, the cut end surface of the base remaining in the concrete foundation is thinner than the lower part, and it becomes more difficult to inject the filler. Although it is possible to use a chemical material such as an epoxy resin having a good filling property even for a narrow gap, this type of filling material is expensive and has a problem that it is inferior in economic efficiency.

  The present invention has been made to solve such a problem. An existing steel pipe column whose base is hardened by a concrete foundation is cut, and a new steel pipe column is formed in the base of the existing steel pipe column left in the concrete foundation. Steel tube pillars that are inserted into the base of the steel tube and solidified by the filler, or steel tube columns that are inserted into the vertical hole formed in an appropriate rigid base similar to this and solidified by the filler In the structure, it is an object of the present invention to provide a standing structure of a steel pipe column that can easily inject a filler, has good surroundings, and can sufficiently secure the standing strength of the steel pipe column.

  In order to achieve the above-described object, the steel pipe column erecting structure of the present invention is a steel pipe column erecting structure in which the base of the steel pipe column is inserted into a vertical hole formed in the foundation and fixed by a filler. The steel pipe column is formed so that the cross-sectional area of the base is smaller than the cross-sectional area of the ground part exposed above the foundation, and the base part and the ground part are continuous via the stepped part, A protruding portion is provided in the vicinity of the stepped portion, and the protruding portion is held in contact with the surface of the foundation.

  According to the present invention, even when the diameter of the ground portion of the steel pipe column is approximated to the diameter of a vertical hole formed in an appropriate rigid base such as the base of a cut existing steel pipe column, the base portion of the steel pipe column is Since it can be made thinner and appropriate clearance can be secured between the base and the vertical hole, it becomes easier to insert the base of the steel pipe column and injection of filler, improve workability, and improve the connection with the vertical hole. Fixing strength can be increased.

  In addition, by providing an overhang on the steel pipe column and bringing it into contact with the surface of the foundation, it is easy to adjust the level when installing the steel pipe column, and the stability of the steel pipe column at the subsurface is improved. Can be made.

  In this invention, if the overhanging part is formed by welding a substantially disc-shaped base plate and a rib plate for stiffening provided on the upper side of the pace plate to the steel pipe column, bending at the ground part of the steel pipe column is possible. Stiffness is also strengthened.

  Furthermore, if the projecting part as described above is fastened and fixed to an anchor bolt or insert nut embedded and fixed in the foundation, the external force acting on the steel pipe column is transmitted to the foundation, and the strength against the external force in the bending direction and the drawing direction Is further improved.

  Furthermore, in the present invention, an appropriate number of openings may be formed at appropriate intervals in the base portion of the steel pipe column, and the inside and outside of the base portion may be filled with the filler through the openings. In this way, by uniformly filling the vertical hole with the filler, the fixing strength between the steel pipe column and the vertical hole can be further increased. It is also possible to inject a filler into the vertical hole from the inside of the steel pipe column using the internal space of the steel pipe column after inserting the base of the pipe column into the vertical hole.

  If the shape of the opening is an elongated hole that is elongated in the vertical direction, and the openings are arranged in a staggered manner, the filler can be more easily rotated.

  As described above, the standing structure of the steel pipe column of the present invention is configured such that an appropriate clearance can be secured between the vertical hole by making the cross-sectional area of the base part of the steel pipe column smaller than the cross-sectional area of the ground part. Therefore, it becomes easy to inject the filler into the vertical hole, the workability is improved, and the base portion of the steel pipe column and the vertical hole can be firmly fixed.

  Moreover, the workability | operativity and stability at the time of constructing a steel pipe pillar improve by providing an overhang | projection part in a steel pipe column and making this overhang | projection contact the surface of a foundation. By increasing the rigidity of the overhanging portion and connecting it to the foundation, the strength of the steel pipe column is further enhanced.

  As an embodiment of the present invention, a case where a new steel pipe column is erected in the base portion of an existing steel pipe column cut and removed will be described as an example with reference to the drawings. Such rebuilding work of the steel pipe columns includes the process of cutting the existing steel pipe columns leaving the base, inserting the new steel pipe columns into the base of the remaining existing steel pipe columns, and the new steel pipe columns. This comprises a step of solidifying the periphery of the base with a filler. Hereinafter, it demonstrates in order of each process.

  First, as shown in FIG. 1, the existing steel pipe column 2 whose base 21 is hardened by the concrete foundation 1 is cut at the surface of the concrete foundation 1. When there are unhealthy places such as irregularities and cracks on the surface portion of the concrete foundation 1, the surface portion of the concrete foundation 1 should be repaired flatly by, for example, removing a part of the surface. Although the existing steel pipe column 2 illustrated in FIG. 1 is a tapered pole with a circular cross section, the existing steel pipe column 2 to which the present invention can be applied may be a steel pipe column or a straight pole with a polygonal cross section.

  As a method of cutting the existing steel pipe column 2, cutting with a tool such as gas fusing or cutter is possible. However, if the reuse of the base 21 is taken into consideration, it is possible to obtain a smooth cut surface with a cutter. Cutting is preferred. By this cutting step, the base 21 that supported the existing steel pipe column 2 is left in the concrete foundation 1. The base 21 is generally hollow throughout the entire embedding depth, although there is some concrete wraparound from the lower end in the construction at the time of standing. In this way, the vertical hole 20 for standing a new steel pipe column is prepared.

  Next, as shown in FIG. 2, the new steel pipe column 3 is inserted into the vertical hole 20. The new steel pipe column 3 is distinguished from a base portion 31 inserted into the vertical hole 20 and a ground portion 32 exposed to the ground, and the cross-sectional area of the base portion 31 is formed to be smaller than the cross-sectional area of the ground portion 32, The base portion 31 and the ground portion 32 are continuous via a substantially tapered stepped portion 33. In the illustrated form, the base 31 of the new steel pipe column 3 is formed in a cross-sectional dimension that can be easily inserted into the vertical hole 20 and can secure a sufficient gap with the vertical hole 20. The ground portion 32 is formed to have the same tapered shape as the existing steel pipe column 2. Moreover, the base part 31, the step part 33, and the ground part 32 of the new steel pipe column 3 are formed so that it may become an integral hollow steel pipe column by hot processing.

  A plurality of openings 34 are discretely formed in the base 31 of the new steel pipe column 3. This opening 34 is for smoothly circulating the filler 4 into and out of the base 31 of the newly installed steel pipe column 3, and considering the fluidity of the filler 4 and the strength reduction of the base 31 due to the cross-sectional defect, The shape and arrangement are set appropriately. In the illustrated embodiment, the shape of the opening 34 is a long hole extending in the depth direction so that the filler 4 smoothly wraps around all depths, and the openings 34 are arranged in a staggered manner to Consideration is given so that the cross-sectional strength does not change significantly in the depth direction.

  Further, in the vicinity of the stepped portion 33 in the new steel pipe column 3, an overhang portion 37 made of a steel plate base plate 35 and a rib plate 36 is provided. The base plate 35 is formed in a substantially disc shape, and the rib plates 36 are disposed on the upper surface of the base plate 35 at appropriate intervals so as to stiffen the base plate 35 so as not to bend in the out-of-plane direction. The joint portions of the base plate 35, the rib plate 36, and the new steel pipe column 3 are fixed by welding.

  The overhanging portion 37 abuts on the surface of the concrete foundation 1 when the new steel pipe column 3 is erected, serves as a stopper for holding the new steel pipe column 3 at an appropriate level, and the new steel pipe column 3 tilts. To improve the stability. If it is such a function, it is only necessary to design a strength that can withstand the weight of the newly installed steel pipe column 3 and a slight amount of added stress. Considering that the weight of the newly installed steel pipe column 3 is small, it is relatively light. Just structure.

  On the other hand, as shown in the drawing, the strength and width of the overhang portion 37 are increased, a bolt hole is formed in the base plate 35, and the bolt is fixed to the anchor bolt 11 and the insert nut that are embedded and fixed in the concrete foundation 1. it can. By adopting such a structure, the overhanging portion 37 also functions as a reinforcing member against a bending moment in a strong wind, an external force in the pulling direction, etc., so that the strength of the newly installed steel pipe column 3 near the ground portion is further improved. A strong connection structure can be obtained.

  The new steel pipe column 3 is erected in the vertical hole 20 and the filler 4 is injected into the vertical hole 20. The injection of the filler 4 should be performed either before or after the step of inserting the new steel pipe column 3. Can do. In the method of injecting the filler 4 in advance before the new steel pipe column 3 is inserted, the filler 4 rotates well inside and outside the base portion 31 of the new steel pipe column 3 and a gap between the fillers 4 is difficult to be formed. Easy to obtain. However, if the filler 4 is injected into the vertical hole 20, it is necessary to insert the new steel pipe column 3 quickly and without delay.

  On the other hand, in the method of injecting the filler 4 after inserting the new steel pipe column 3 into the vertical hole 20, the time management of the work process can be afforded. However, since it is not easy to inject the filler 4 from between the vertical hole 20 and the base portion 31 of the new steel pipe column 3, an appropriate injection hole 38 is formed in the ground portion 32 of the new steel pipe column 3, and the new steel pipe is formed therefrom. It is preferable to inject the filler 4 inside the pillar 3. Even in this case, since the filler 4 wraps around the entire inside of the vertical hole 20 via the opening 34 formed in the base 31 of the new steel pipe column 3, a good connection structure can be obtained.

  Thus, according to the standing structure of the steel pipe column of the present invention, the filler 4 can be easily injected into the vertical hole 20 and the filler 4 smoothly circulates. Inexpensive and readily available ordinary mortar and cement milk can be used without any particular inconvenience. Besides, general fillers 4 such as ready-mixed concrete, soil cement, special mortar, epoxy resin and other chemical materials can be widely used.

  3A to 3D show another embodiment of the present invention. As shown in FIG. 3 (a), the base portion 31, the ground portion 32, the stepped portion 33, and the overhang portion 37 of the new steel pipe column 3 according to the present invention are substantially tapered. A configuration in which the overhanging portion 37 is provided from the stepped portion 33 to the vicinity of the upper end of the base portion 31 as shown in FIG. 33 is located across the top and bottom of the surface of the concrete foundation 1, and the overhanging portion 37 is provided in the vicinity of the upper portion of the stepped portion 33, as shown in FIG. The stepped portion 33 may be positioned below the surface of the concrete foundation 1, and the overhang portion 37 may be provided near the lower end of the ground portion 32. Furthermore, as another modification, as shown in FIG. 3D, the base plate 35 of the overhanging portion 37 is formed so as to also serve as the stepped portion 33, and the ground portion 32 and the base portion 31 are formed above and below the base plate 35. It is also possible to adopt a form in which each is welded.

  In the description of the above-described embodiment, when the new steel pipe column 3 is erected in the vertical hole 20, the axial center of the vertical hole 20 and the new steel pipe column 3 are aligned. However, eccentricity is allowed in design. In such a case, the newly installed steel pipe column 3 may be erected in one direction within the vertical hole 20.

  Moreover, some changes are possible also about the form of the overhang | projection part 37, for example, the form in which any of the base plate 35 and the rib plate 36 is not present, the form in which the base plate 35 is not continuous in the circumferential direction of the newly installed steel pipe column 3, The present invention can also be applied to a form in which the base plate 35 and the rib plate 36 are eccentrically projected to the side on which a large bending moment acts.

  In addition, the foundation is not limited to the independent concrete foundation 1 as illustrated, but may be a continuous foundation in which a plurality of foundations are connected by beams, or a part of a ground part or a retaining wall of a building structure made of reinforced concrete. There may be. As for the vertical hole 20, not only the base 21 obtained by cutting the existing steel pipe column 2 as illustrated, but also a vertical hole similar to this can be used as appropriate.

It is sectional drawing which shows the cutting process of the existing steel pipe column in embodiment of this invention. It is sectional drawing which shows the standing process of the newly installed steel pipe column in embodiment of this invention. It is sectional drawing which shows the form of the newly installed steel pipe pillar which concerns on other embodiment of this invention. It is sectional drawing which shows an example of the rebuilding method of the conventional steel pipe pillar.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete foundation 11 Anchor bolt 2 Existing steel pipe pillar 20 Vertical hole 21 Base 3 New steel pipe pillar 31 Base 32 Ground part 33 Step part 34 Opening part 35 Base plate 36 Rib plate 37 Overhang part 4 Filling material

Claims (5)

In the upright structure of the steel pipe column where the base of the steel pipe column is inserted into the vertical hole formed in the foundation and fixed by the filler,
The steel pipe column is formed so that the cross-sectional area of the base is smaller than the cross-sectional area of the ground part exposed above the foundation, and the base part and the ground part are continuous via the stepped part, An upright structure for a steel pipe column, characterized in that an overhang is provided in the vicinity of the stepped portion, and the overhang is held in contact with the surface of the foundation.   The steel pipe according to claim 1, wherein the projecting portion is formed by welding a substantially disc-shaped base plate and a stiffening rib plate provided on the upper side of the pace plate to the steel pipe column. Standing structure of pillars.   The upright structure of the steel pipe column according to claim 1, wherein the overhang portion is fastened and fixed to an anchor bolt or an insert nut embedded and fixed in the foundation.   2. The steel pipe column upright structure according to claim 1, wherein an appropriate number of openings are formed at appropriate intervals in the base portion of the steel pipe column, and fillers are filled into the inside and outside of the base through the openings. .   6. The standing structure of a steel pipe column according to claim 5, wherein the openings are formed in an elongated hole shape in the vertical direction and are arranged in a staggered manner.

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