JP3020343B2 - Column base structure using hollow tube and method of constructing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column base structure used as a pier, a main tower, or a support in another structure of a bridge, and a method of constructing the column base structure.

[0002]

2. Description of the Related Art As a structure of a columnar structure having a relatively large scale, there are a reinforced concrete structure, a steel structure using a steel pipe, a concrete filled steel pipe structure, and the like. Reinforced concrete structures are generally economical and are widely used structures. As a method of constructing a column-base structure of a reinforced concrete structure as a large-scale pier or tower-like structure, a sliding form method and a japing form method are known, and a moving form is sequentially moved upward. Then, reinforcement and concrete placement are performed to construct a column base structure. 26 and 27 show an outline of a mountain bridge and a method of constructing a pier of a reinforced concrete structure using a movable formwork. In FIG. 26, a bridge girder 21 is an abutment 23a, 23b at both ends and an intermediate pier 22a, 22b. Supported by Taking the pier 22a as an example,
As shown in FIG. 27, the temporary steel column 2
5 is erected, the movable formwork 26 is installed, and after the rebar work, concrete 27 is poured. Hereinafter, the jack-up of the movable formwork 26, the arrangement of the reinforcing bars, and the placing of the concrete 27 are sequentially repeated upward to construct a column-base structure having a reinforced concrete structure. The steel structure can build a column-base structure in a short construction period by successively adding steel pipes etc. of a predetermined length upward by welding or bolting, etc. There is an advantage that reliability in terms of surface is high. Furthermore, there is a concrete-filled steel pipe structure as a structure excellent in workability, strength, weather resistance and the like. As a column base structure having a concrete filled steel pipe structure, for example, Japanese Patent Publication No. 3-54724,
Japanese Patent Application Publication No. 54725/1995, Japanese Patent Publication No. 3-54726, and Japanese Patent Publication No. 3-52727. The column-base structure described in these publications has an unbonded concrete-filled steel pipe structure that cuts off the edge between the steel pipe and the filled concrete, so that the steel pipe portion yields due to the compressive force acting on the concrete-filled steel pipe. And prevent local buckling and loss of restraint on filled concrete. Among them, those described in Japanese Patent Publication No. 3-54724 and Japanese Patent Publication No. 3-52727 have concrete-filled steel pipes having a thick column portion and a narrow column portion, and having different diameters as they go upward. By connecting a plurality of stages so as to reduce the diameter, the section regarding the bending strength is rationalized.

[0003]

When a column-base structure of a reinforced concrete structure is constructed by a sliding form method or a japing form method, scaffolds, supports, and many other temporary materials are required. It takes time and effort to assemble the movable formwork, jack up, dismantle, etc., and requires many steps and construction periods in the construction,
There is also a problem that there are many works at high places and various considerations are required also in terms of safety. A column-base structure of steel structure using steel pipes, etc. is excellent in workability and can shorten the construction period if the scale is relatively small, and has a great economic effect. However, when it is a large structure, it is carried to the site. And the problem that a large crane is required for building. Another problem is that the cost of materials is higher than in reinforced concrete structures. The concrete-filled steel pipe structure is superior in strength and weather resistance, and is advantageous in terms of workability compared to the reinforced concrete structure.However, the cost of materials is high, and in the conventional structure and construction method, large machines such as hoists are used. Further, there is a problem that a corresponding construction space is required. In addition, in the column-base structure of the concrete-filled steel pipe structure described in Japanese Patent Publication No. 3-54724 and Japanese Patent Publication No. 3-54727, the transmission of the tensile force between the narrow column and the large column is large. Reinforcement with anchors in the columns and rebars that penetrate the narrow and thick columns vertically, complicating the detail of the joints, and reinforcing bars that penetrate the narrow and thick columns Work is required, which is a bottleneck in construction. In the case of steel structures and concrete-filled steel pipe structures, the surface of steel pipes or the like is usually given a heavy-film corrosion-resistant coating or the surface is plated with zinc plating, aluminum plating, etc., for the purpose of ensuring weather resistance. Processing needs to be performed. In that case, in order to reduce the on-site painting work and the like, it is desirable to carry in a member that has been subjected to a surface treatment in advance and assemble it. However, in a structure that requires on-site welding or bolt joints, those that have been surface-treated in advance cannot be used, or even if they can be used, the joints will be damaged by on-site welding or bolt joint processing, and after joining, Since it is necessary to repair the surface treatment portion such as painting again, there is a problem that corrosion often occurs due to poor quality of the portion. The present invention is intended to solve the problems in the prior art as described above, strength, excellent workability, especially in a narrow place where the working space is limited, or even in poor places in the mountainous construction conditions and the like Another object of the present invention is to provide a structure of a column base structure capable of performing an efficient construction without requiring a large-sized machine and equipment, and a construction method for efficiently constructing the column base structure.

[0004]

A column base structure using a hollow tube according to the present invention is constructed by connecting hollow tubes having different diameters in a plurality of stages so that the diameter decreases as going upward. By inserting the lower end of the upper hollow tube into the upper end of the hollow tube for a predetermined length, filling concrete between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube, and curing the concrete. The upper and lower hollow tubes are combined and integrated. In addition, the hollow pipe referred to here includes a large-diameter pipe called a cell or the like, other than a normal steel pipe, a steel pipe assembled, a composite steel pipe member having a centrifugally formed concrete inside the steel pipe or It also includes hollow concrete members and the like. The hollow tube is not limited to a circular cross section, but may have a square cross section or the like. By filling concrete over the entire length of the hollow pipe, a concrete-filled steel pipe structure or a similar structure is obtained. However, a structure in which concrete is filled only in a joint portion where the lower end of the upper hollow pipe is inserted may be used. In this case, the lower end of the concrete filling portion needs to be closed in some form, such as using a lid. Further, for example, a configuration in which the lower part of the column base structure on which a large compressive force and bending moment acts is a concrete-filled steel pipe structure, and the upper part is a steel pipe structure in which concrete is not filled is also possible. In order to enhance the integrity of the hollow tube and concrete, it is necessary to project sharks such as stud bolts on the inner surface of the lower hollow tube to be joined and the outer surface of the upper hollow tube, It is also conceivable to use a steel pipe with a projection or the like. The upper end of concrete filled between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube will be exposed as it is, but by providing a cover to cover the concrete upper surface in this part, It is necessary to prevent the deterioration of the. When concrete is filled over the entire length of the hollow tube, such as a concrete-filled steel tube structure, an unbonding process is performed between the inner surface of the hollow tube and the concrete with asphalt, grease, or the like, so that a non-adhering state is obtained. It is also possible. In this case, the filled concrete bears the compressive force, and the yielding and local buckling of the hollow tube due to the large compressive force are prevented, so that the concrete confining effect of the hollow tube is maintained, and the cross section of the column base structure is maintained. Can be reduced. Further, in the present invention, a hollow tube in which the surface of a steel tube or the like as the hollow tube has been subjected to a thick film heavy anticorrosion coating or a surface treatment such as zinc plating or aluminum plating in advance can be used. That is, in the column-base structure of the present invention, the joining of the hollow tubes is performed by filling the joints with concrete,
There is no damage to the surface treatment part due to on-site welding and bolt joint processing, and it is possible to use a hollow tube that has been subjected to surface treatment as it is, it can be installed without impairing the surface treatment effect, surface treatment damage at the site No repair work is required. One of the construction methods of the column base structure of the present invention is a method for constructing a column base structure in which hollow pipes having different diameters are connected in a plurality of stages so that the diameter decreases as going upward, concrete is converted to the full length of the hollow pipe. In the case of filling over, after filling concrete to a predetermined height inside the lower hollow tube, the upper hollow tube is built into the upper end of the lower hollow tube,
Concrete is filled between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube, and the hollow tubes are joined and integrated.
By repeating this process sequentially in the height direction, a column base structure having a desired height can be constructed. Another method of constructing the column base structure of the present invention is to stack a plurality of hollow tubes at a column base construction position in a state where a hollow tube having a smaller diameter is housed inside a hollow tube having a larger diameter. After fixing together and fixing the outer hollow tube with a large diameter, the inner hollow tube is sequentially moved upward to a predetermined height, and the inner surface of the outer hollow tube and the outer surface of the inner hollow tube are moved together. The space between the hollow tubes is connected and integrated by filling concrete between them, and a column base structure having a desired height is constructed. The installation of the hollow tube at the column base construction position and the upward movement can be performed using a lifting machine such as a crane, but the upward movement is performed by using the internal space of the hollow tube inside the hollow tube. It is also possible to do this with a shoring and jacks installed in the area. In that case, there is no need for a large crane,
Further, there is an advantage that a large work space is not required around the column base structure. The upward movement of the superimposed hollow tubes can also be performed using a suspending member such as a wire or a tension rod. When using a hanging material, the lower part of the inner hollow tube is suspended from the upper part of the outer hollow tube via the hanging material, and the hanging material is a winch or the like for a wire, and a center hole for a tension rod. The inner hollow tube can be pulled up by pulling using a jack or the like. By installing an upper structure to support the bridge girder etc. in advance above the innermost hollow tube that constitutes the multi-stage column base structure, streamlining of the construction including the upper structure Can be achieved. Further, in the construction method of the present invention, the hollow tube having been subjected to surface treatment in advance can be used as the hollow tube, as described for the column base structure.

[0005]

FIGS. 24 and 25 show multi-stage concrete with different diameters.
For the column base structure of the filled steel pipe structure, the upper steel pipe 3
2b and lower steel pipe 32a are buried in concrete 33
Penetrates the anchor bar 34 and the steel pipes 32a, 32b
A conventional structure (FIG. 2)
4) and the lower side of the upper steel pipe 32b and the lower steel pipe 32a
Are overlapped by a predetermined length, and the lower side of the upper steel pipe 32b is
Corresponding to the present invention in which
It is a comparison of the stress state in the structure (FIG. 25).
Considering the joint strength RM in the structure of
Swell. RM = ΣC_x・ B_v+ ΔT_x・ B_v  Where C_x: Support pressure T at the lower end of the steel pipe 32b_x: Anchor: Tensile force of bar 35 and reinforcing bar 34_v: Neutral axis YY from the point of supporting force at the lower end of steel pipe 32b
Horizontal distance to B_v: From anchor bar 35 and reinforcing bar 34 to neutral axis YY
On the other hand, consider the joint resistance RM in the structure
Is as follows. RM = ΣC_x・ B_v+ Σh_x・ B_h + Σn_x・B _n  …… (2) where C_x: Support pressure at the lower end of steel pipe 32b h_x: Bearing pressure of the bearing surface on the side of steel pipe 32b + concrete
Adhesive force with 33 n_x: Adhesion force between the side of the steel pipe 32b and the concrete 33 B_h: Neutral from the bearing point of the bearing surface on the side of the steel pipe 32b
Horizontal distance B to axis XX_n Adhesion work between the side of steel pipe 32b and concrete 33
Horizontal distance from the point of use to the neutral axis XX As described above, in the case of
According to the present invention, there are only embedded reinforcing bars and anchor bars.
In the corresponding structure, the lower end of the upper steel pipe is
Since it is inserted into the
Expected pressure and concrete adhesion.

[0006]

Next, the illustrated embodiment will be described. FIG. 1 shows an outline of a case where the column base structure of the present invention is used as a bridge pier, and FIGS. 2 and 3 are views corresponding to a vertical cross section thereof. In this embodiment, the main body of the column base structure 1 is composed of a plurality of steel pipes 2a, 2b,... Having different diameters, and concrete 3a, 3b,. Steel pipe 2
are smaller in diameter as they go upward. In FIG. 1, a cross beam 4 for supporting a bridge girder portion of a bridge is provided at the upper end of a fourth stage steel pipe 2d. Each steel pipe 2
The joining of a, 2b,... is performed by inserting the lower end of the upper steel pipe 2 into the upper end of the lower steel pipe 2 for a predetermined length, and overlapping the steel pipes 2 with each other. The stress between the upper and lower steel pipes 2 is transmitted via 14.
2 and 3 show concrete 3 over the entire length of steel pipe 2.
Concrete filled steel pipe structure filled with
Concrete 14 is applied only to the seam, that is, the joint 5.
May be used.

Although not shown, in order to enhance the integrity of the steel pipe 2 and the concrete 3, a shakey such as a stud bolt is projected from the inner surface of the lower steel pipe 2 or the outer surface of the upper steel pipe 3. Alternatively, there is a method in which a steel pipe with a projection or the like is used as the steel pipe. FIG. 2 shows a case where the upper end of the concrete 14 filled in the joint 5 is left exposed. In FIG. 3, a skirt-shaped cover 6 is previously welded to the lower part of the upper steel pipe 2 at the joint 5. The cover 6 protects the surface of the concrete 14 in a state where the steel pipe 2 on the upper side is added and is prevented from being deteriorated.

FIG. 4 to FIG. 6 and FIG. 7 to FIG. 10 show the construction procedure in the method of constructing a column base structure according to the present invention. Perform the construction according to the procedure. Section 1 steel pipe or cell (hereinafter simply referred to as steel pipe) 2
a is erected by the crane 7 on a foundation (not shown) at the installation position of the column base structure 1 as a bridge pier (see FIG. 4). Concrete 3a is filled to a predetermined height in the steel pipe 2a (see FIG. 5). The steel pipe 2b of the second section is erected on the filled concrete 3a (see FIG. 6). Concrete 14a is filled in the gap between the overlapped portions of the first section steel pipe 2a and the second section steel pipe 2b to fix the second section steel pipe 2b, and the concrete 3b is filled to a predetermined height in the steel pipe 2b (FIG. 7). The steel pipe 2c of the third section is built on the filled concrete 3b (see FIG. 8). Concrete 14b is filled in the gap between the overlapped portions of the second section steel pipe 2b and the third section steel pipe 2c to fix the third section steel pipe 2c, and the concrete 3c is filled to a predetermined height in the steel pipe 2c. The steel pipe 2d of the fourth section is erected (see FIG. 9). Concrete 14c is filled in the gap between the overlapped portion of the third section steel pipe 2c and the fourth section steel pipe 2d to fix the fourth section steel pipe 2d, and the concrete 3d is filled in the steel pipe 2d to form an upper structure. Attach the cross beam 4 of FIG.
reference).

In the above construction method, the upper and lower steel pipes 2
a, 2b,... are not welded or bolted together, and only a simple scaffold is built around the crane 7 if necessary.
It is possible to build while stabilizing sequentially from the bottom. Further, the structure is such that stress is transmitted in the overlapping portions of the steel pipes 2a, 2b,..., And does not require a complicated detail at the joint portion 5 and can avoid complication of work due to rebar assembly.

FIG. 11 to FIG. 13 and FIG. 14 to FIG. 17 show construction steps in another embodiment of the method of constructing a column base structure according to the present invention. The steel pipe 2a of the first section is erected on the foundation of the installation position of the column base structure 1 as a pier, and the gantry 8 is installed inside the steel pipe 2a of the first section. Steel pipe 2b, 2
The c and 2d are set inside by the crane 7 (see FIG. 11). Steel shell 4a constituting the cross beam 4 above the steel pipe 2d of the fourth section
(See FIG. 12). The jack 9 is installed in the steel pipe 2a of the first section, the support 10a is assembled while jacking up, and the steel pipes 2b, 2c, 2d and the steel shell 4a of the cross beam 4 from the second section are pushed upward (see FIG. 13). ). This operation can be performed by using the crane 7 together. In addition, a scaffold or a shoring is formed around the column base structure 1 under construction as necessary,
Provide a wire or other support mechanism. With the upper end of the first section steel pipe 2a and the lower end of the second section steel pipe 2b overlapping by a predetermined length, concrete 3a is filled up to a predetermined height in the first section steel pipe 2a and hardened concrete. The support 10b is assembled while jacking up the steel pipe 3a.
c, 2d and the steel shell 4a of the cross beam 4 are pushed upward (see FIG. 14). With the upper end of the second section steel pipe 2b and the lower end of the third section steel pipe 2c overlapping by a predetermined length, the concrete 3b is filled to a predetermined height in the second section steel pipe 2b and hardened concrete 3b The support 10c is assembled while jacking up the steel pipe, and the steel pipe 2d of the fourth section and the steel shell 4a of the cross beam 4 are pushed upward. Concrete 14 is applied to the overlapping portion of the first section steel pipe 2a and the second section steel pipe 2b.
a, and the steel pipe 2a of the first section and the steel pipe 2b of the second section are joined.
Simultaneously with concrete 3a or concrete 3a
May be filled immediately after filling (see FIG. 15). Concrete 3c is filled to a predetermined height in the steel pipe 2c of the third section, with the upper end of the steel pipe 2c of the third section and the lower end of the steel pipe 2d of the fourth section overlapping by a predetermined length (see FIG. 16). ). The concrete 4b is filled in the steel pipe 2d of the fourth section and the steel shell 4a of the cross beam 4 to complete the column base structure 1 (FIG. 17).
reference).

In the above-described construction method, the steel pipe 2 and the cross beam above the column base structure 1 are formed by the jack 9 and the supporter 10 using the internal space of the hollow pipe without necessarily using a large crane or the like. 4 can be pushed up to a predetermined height, and there is an advantage that a large working space is not required around the column base structure 1. In addition, since the cross beam 4 for supporting the bridge girder can be attached near the ground, work at high places can be reduced. In addition, the shoring 10 can also be made to function as a substitute for a reinforcing steel bar by embedding and killing in the concrete 3.

FIGS. 18 to 23 show still another embodiment of the method of constructing a column base structure according to the present invention, wherein a plurality of steel pipes 2a, 2b,. The point of installation together is the same as in the case shown in FIGS. In the case of FIGS. 11 to 17, the steel pipes 2 a, 2 b,... Are pushed up by jack-up using the support 10, whereas in the present embodiment, the operation of the winch 12 on the ground using the wire 11 is performed. Each upper steel pipe 2b,
2c can be lifted, and construction is performed in the following procedure. The steel pipe 2a of the first section is installed at a predetermined construction position,
The wire 11 is attached to the pulleys 13 provided above and below a (see FIG. 18). The steel pipes 2b and 2c from the second section onward are set inside, and the wire 11 is passed between the pulleys 13 above and below the respective steel pipes 2a, 2b and 2c (see FIG. 19). By operating the winch 12 on the ground, the wire 11 is wound up, and the steel pipes 2b and 2c of the second and third sections are pulled up (see FIGS. 20 and 21). The upper end of the first section steel pipe 2a and the lower end of the second section steel pipe 2b, and the upper end of the second section steel pipe 2b and the third section steel pipe 2c
Are supported in a state in which the lower end portions overlap each other by a predetermined length (see FIG. 22). Concrete 3 is filled in each of the steel pipes 2a, 2b, 2c, and concrete 14a, 14b in the overlapping portion is filled.
Thereby, the steel pipes are integrated (see FIG. 23).

FIGS. 18 to 23 show only the construction of the main body portion of the column base structure 1. However, when used as a pier, a cross beam or the like is attached to the upper portion of the column base structure 1 in FIGS.
This is similar to the seventh embodiment. In the construction method of the embodiment shown in FIGS. 18 to 23, since the steel pipes 2a, 2b, and 2c are raised by operating the winch 12 on the ground, there is an advantage that work at a high place is greatly reduced.

In the embodiment shown in FIGS. 18 to 23, the wire 11 is pulled up. However, the upper end of the superposed outer steel pipe and the lower end of the inner steel pipe are connected by a tension rod via a suitable metal fitting or the like. A method is also conceivable in which the tension rod is pulled up at the upper end of the outer steel pipe using a center hole jack or the like, so that the inner steel pipe is sequentially pulled upward.

In the embodiments shown in FIGS. 18 to 23, the concrete 3 inside is shown as being filled at once.
Of course, it is possible to fill from the bottom at a predetermined height, and in some cases, for some or all of the steel pipes, a structure in which only the overlap portion, that is, the joint is filled with concrete 14 and the inside is not filled with concrete. Is also good.

[0016]

(1) Hollow tubes of different diameters constituting a column-base structure are overlapped with each other by a predetermined length, and the upper and lower hollow tubes are joined via a concrete filled therebetween. In addition, against the bending acting on the column base structure, the force can be transmitted by the bearing force of the concrete in the overlap portion, and the structure of the joint can be simplified. (2) A highly reliable joint is formed without field welding. (3) Processing for bolt joining is unnecessary, and a steel pipe or the like can be used as it is. (4) Hollow pipes are joined by filling concrete into joints and do not require on-site welding or bolt joints. Use hollow pipes that have been subjected to surface treatment such as painting or plating in advance. Can be. In addition, on-site repair work for a damaged surface treatment caused by welding or processing of a bolted joint can be omitted, and the on-site work can be simplified. (5) Since it is a structure in which a plurality of stages are connected so that the diameter decreases as going upward, it is a reasonable structure in a column base structure in which a large compressive force and a large bending moment act on a lower portion, and the sectional waste is reduced. Few. In addition, it is not necessary to change the diameter gradually from one end to the other end, and a hollow tube having a constant diameter can be used. (6) Concrete may be filled not only at the joints but also over the entire length of the hollow tube. Particularly, the lower part of the column base structure that requires a large load-bearing capacity and bending strength is made into a concrete-filled structure, thereby providing strength and weather resistance. A column base structure with excellent properties. (7) By providing a shark such as a stud bolt at the portion of the hollow tube that comes into contact with the concrete, or by using a steel tube with a projection for the hollow tube, the adhesive force with the concrete is increased, and the upper and lower portions have different diameters. Is good. By actively integrating hollow pipes made of concrete and steel pipes, the hollow pipes bear the tensile force generated by bending, etc., eliminating the need to reinforce filled filling concrete with steel bars, etc. Significant labor saving due to unnecessary and simple construction makes it possible to adopt a simple construction method. (8) In the case where the gap between the inner surface of the hollow tube and the concrete to be filled is in a non-adhered state, similar to the unbonded concrete-filled steel tube structure described as the conventional example, local buckling of the hollow tube. The strength of the joint between the upper and lower hollow pipes can be ensured while preventing the like and improving the proof stress by the concrete restraining effect. (9) By covering the upper end of the lower hollow tube where the concrete is exposed with a cover, deterioration can be prevented at that portion, and a structure that does not require repair or the like for a long time can be obtained. (10) In the method of constructing a column-base structure according to the present invention, when concrete is filled over the entire length of the hollow tube, a hollow tube having a smaller diameter is installed above the lower hollow tube filled to a predetermined height. In doing so, the inner space of the lower hollow tube can be used, so the upper hollow tube can be stabilized, and it can be easily joined simply by filling concrete into the gap without the need for welding or bolting Work can be done. (11) The hollow pipes having different diameters are overlapped in a state where the hollow pipes having smaller diameters are accommodated inside the hollow pipes having larger diameters, and the construction is performed while sequentially pulling up the inner hollow pipes. With this method, the internal space of the hollow tube can be used effectively, and efficient construction can be performed even in a limited space where roads and other structures become obstacles, or in places where scaffolding is poor in mountainous areas. It can be carried out. (12) In a place where the inner hollow pipe is moved upward from a state where the hollow pipes having different diameters are superimposed, the inner hollow pipe is pulled up using a wire, a tension rod, or the like, so that a simple surrounding is obtained. Construction can be performed only by building a scaffold, without necessarily using a large lifting machine,
Economical construction can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline when a column base structure of the present invention is used as a pier.

FIG. 2 is a vertical sectional side view of the column base structure of FIG. 1;

FIG. 3 is a vertical sectional side view showing a modification of the column base structure of FIG. 1;

FIG. 4 is a side view showing a state where the steel pipe of the first section is erected on a foundation at a position where the column base structure 1 is installed by a crane.

FIG. 5 is a vertical sectional side view showing a state where concrete is filled to a predetermined height in a steel pipe in the first section.

FIG. 6 is a longitudinal sectional side view showing a state in which the steel pipe of the second section is built on the concrete filled in the steel pipe of the first section.

FIG. 7 is a longitudinal sectional side view showing a state in which concrete is filled between an overlapping portion of the steel pipe of the first section and the steel pipe of the second section, and concrete is filled in the steel pipe of the second section.

FIG. 8 is a longitudinal sectional side view showing a state where the steel pipe of the third section is laid on the concrete filled in the steel pipe of the second section.

FIG. 9 shows a state in which concrete is filled between the overlapped portions of the steel pipes of the second and third sections and the steel pipe of the fourth section is laid on the concrete filled in the steel pipe of the third section. It is a longitudinal side view shown.

FIG. 10 is a partially longitudinal side view showing a completed column base structure with a horizontal beam.

FIG. 11 is a vertical sectional side view showing a state in which a gantry is installed inside the steel pipe of the first section and the steel pipes of the second and subsequent sections are set inside by a crane.

FIG. 12 is a longitudinal sectional side view showing a state where a steel shell constituting a cross beam is attached to an upper part of the steel pipe of the fourth section.

FIG. 13 is a longitudinal sectional side view showing a state where the steel pipe of the second section and subsequent sections and the steel shell of the cross beam are pushed up.

FIG. 14 is a vertical sectional side view showing a state when pushing up the steel shell of the steel pipe and the cross beam from the third section onward.

FIG. 15 is a longitudinal sectional side view showing a state where the steel shell of the steel pipe and the cross beam in the fourth section is pushed up.

FIG. 16 is a longitudinal sectional side view showing a state in which concrete is filled to a predetermined height in the steel pipe of the third section with the upper end of the steel pipe of the third section and the lower end of the steel pipe of the fourth section overlapping each other. .

FIG. 17 is a longitudinal sectional side view showing a completed column base structure with a horizontal beam.

FIG. 18 is a vertical sectional side view showing a state where the steel pipe of the first section is erected at a predetermined construction position and wires are attached to pulleys provided above and below the steel pipe.

FIG. 19 is a vertical cross-sectional side view showing a state in which the steel pipes of the second and subsequent sections are set inside, and wires are laid over pulleys above and below each steel pipe.

FIG. 20 is a vertical cross-sectional side view showing a state where the steel pipes of the second and third sections are moved upward by a winch on the ground.

FIG. 21 is a vertical sectional side view showing a state where the steel pipes of the second and third sections have been moved up to the upper limit position.

FIG. 22 shows a state in which the upper end of the first section steel pipe and the lower end of the second section steel pipe, and the upper end of the second section steel pipe and the lower end of the third section steel pipe are supported in an overlapping state. FIG. .

FIG. 23 is a longitudinal sectional side view showing a state in which concrete is filled in each steel pipe and the steel pipes are integrated with each other by the concrete in the overlapped portion.

FIG. 24 is a diagram showing a force acting on a joint in a conventional structure.

FIG. 25 is a view showing a force acting on a joint in the column base structure of the present invention.

FIG. 26 is a side view showing an outline of a mountain bridge as a conventional example.

FIG. 27 is a partially longitudinal side view showing a conventional method of constructing a pier using a movable formwork.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Column-base structure 2 Steel pipe 3 Concrete 4 Cross beam 5 Joint 6 Cover 7 Crane 8 Stand 9 Jack 10 Shoring 11 Wire 12 Winch 13 Pulley 14 Concrete

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-90841 (JP, A) JP-B 3-54724 (JP, B2) JP-B 3-54727 (JP, B2) (58) Field (Int. Cl. ⁷ , DB name) E01D 19/02 E01D 21/00

Claims (8)

(57) [Claims] 1. A plurality of hollow tubes having different diameters are connected to each other so as to decrease in diameter as going upward, and a lower end of an upper hollow tube is inserted into an upper end of a lower hollow tube by a predetermined length. A concrete-filled space between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube, and the hollow tubes are connected and integrated with each other. A pillar-base structure using a hollow tube, characterized in that a concrete-filled portion between the inner surface of the hollow tube and the outer surface of the upper hollow tube is provided with a shark. 2. A plurality of hollow tubes having different diameters are connected in a plurality of stages so that the diameter decreases as going upward, and the lower end of the upper hollow tube is inserted into the upper end of the lower hollow tube by a predetermined length. A concrete structure is filled between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube, and the hollow tubes are combined and integrated with each other. A column-base structure using a hollow pipe, wherein the pipe is a steel pipe having a protrusion on at least one of an inner surface and an outer surface. 3. The column base structure using a hollow tube according to claim 1, wherein each of the hollow tubes is filled with concrete over the entire length of the hollow tube. The wherein the surface of said hollow tube, column base structure using a hollow tube according to any one of claims 1 to 3, characterized in that pre-surface-treated. 5. A method of constructing a column-base structure comprising a plurality of hollow tubes having different diameters connected in a plurality of stages so as to decrease in diameter as going upward, wherein a lower portion of the hollow tube has a predetermined height inside the lower hollow tube. After filling with concrete, an upper hollow tube is erected inside the upper end of the lower hollow tube, and concrete is placed between the inner surface of the lower hollow tube and the outer surface of the upper hollow tube. The step of filling and joining and integrating the hollow tubes is sequentially repeated in the height direction to construct a column base structure having a desired height.
Before moving upward, the top of the innermost hollow tube
In addition, an upper structure provided above the column base structure is installed.
Structure of the column base structure using a hollow tube, characterized in that leave
Construction method . 6. The construction of a column base structure using a hollow tube according to claim 5 , wherein the upward movement of the inner hollow tube is performed by a support and a jack installed in the outer hollow tube. Method. 7. The upward movement of the inner hollow tube is performed by suspending and supporting the lower portion of the inner hollow tube from above the outer hollow tube via a suspending member, and pulling the suspending member. The method for constructing a column-base structure using a hollow tube according to claim 5, which is performed by pulling up an inner hollow tube. 8. The method according to claim 5 , wherein the surface of the hollow tube is subjected to a surface treatment in advance.