JPH073809A - Construction method of cylindrical structure body - Google Patents

Abstract

PURPOSE:To enable the construction of a large-sized cylindrical structure body with high strength such as a caisson type pile, a bridge lower structure, etc., and to enable the construction of such a cylindrical structure body in the ground at a low cost. CONSTITUTION:Steel elements 3 forming double steel shells on lip hardwares 7 are subsequently fitted with joints to form cylindrical unit closing cells 2. The upper ends of the unit closing cells 2 are slipped in a zigzag shape for the adjacent steel elements 3 each other, so that horizontal connection sections 6 with the unit closing cells 2 are intermittent. The insides of the double steel shells of the steel elements 3 are filled with concrete, and a monolithic cylindrical structure body 1 of a steel and concrete composite structure is constructed. After the completion of the cylindrical structure body 1, underwater concrete is placed in the front end thereof, and the bottom concrete is placed thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a tubular structure used as a deep foundation pile, a bridge substructure, a shaft, an underground tank, etc. in the field of civil engineering and construction.

[0002]

2. Description of the Related Art Even in a large structure, it is desired to develop a rational construction method by precasting in order to save construction work, improve quality, and improve safety. Previously known document "Precasting in bridge substructure" (Concrete Engineering, Vol.30, No.1)
1, In November 1992, as an example of precasting, a cylindrical concrete unit block 21 manufactured in a factory as shown in FIG. The vertical joint 32 and horizontal joint of the segment 31 type in which the ring shape is divided as shown in FIG. 15 for the PC well construction method in which the pre-tensioning method is used for prestressing in the vertical direction and the cylindrical structure having a larger diameter is connected. A construction with 33 is shown and a joint study is underway.
Further, Japanese Patent Laid-Open No. 1-75710 discloses a liquid storage tank,
As a method of manufacturing a prestressed structure for application to the construction of other tubular structures, etc., a predetermined number of parallel flange steel elements having joints at both ends are joint-fitted to form a closed cell with a double steel shell structure. Is disclosed and a method of forming a steel-concrete composite structure by filling concrete in a double steel shell is disclosed.

[0003]

The application range of the PC well method is limited due to transportation restrictions and various restrictions at the construction site, as described in the above-mentioned document. On the other hand, in the case of the segment type in which the ring shape is divided, in order to realize a highly reliable joint structure that can withstand seismic force, etc., the joint structure becomes complicated and problems of cost and construction arise. It is also possible to increase the size of the unit block or segment in order to reduce the number of joints, but the weight of the unit such as the block becomes large, which makes transportation and handling difficult. On the other hand, JP-A-1-7571
In the invention described in Japanese Patent Publication No. 0, since a steel pipe sheet pile type steel element is used, the weight of the element alone is relatively small, which is advantageous in terms of transportability and handling, but requires concrete filling on site. There is room for improvement in terms of integration at the vertically joined upper and lower ends of the structure, increased strength, and workability when the structure to be built becomes large. An object of the present invention is to provide a method for constructing a large-sized, high-strength tubular structure and further for constructing such a tubular structure in the ground easily and at low cost. is there.

[0004]

According to the present invention, the joints 3 are provided at both ends.
A predetermined number of parallel flange steel elements 3 having C are joint-fitted to form a closed cell of a double steel shell structure of a cylindrical shape or a square tube shape, and the double steel shell is filled with concrete to form concrete. When constructing a tubular structure of a steel-concrete composite structure by solidifying, the adjacent upper and lower ends of the steel elements of predetermined lengths are staggered in a vertical direction at predetermined intervals to fit the joints. The sawtooth unit closed cells 2 are formed, and the joint positions for joining the upper and lower unit closed cells 2 are made discontinuous,
It is characterized in that a tubular structure having a predetermined height or a predetermined depth is constructed by adding unit closed cells to the upper side. The steel element 3 having parallel flanges is composed of an inner and outer flange forming the inner and outer surfaces of the closed cell and one or more webs connecting both flanges, etc., and joints are provided at both ends of the inner and outer flanges. Is. As the main body of the steel element 3, it is possible to use steel plates welded to each other, or a shape steel such as a square steel pipe or an H-shaped steel welded.

Further, the joint portion can be manufactured by welding a half-cut steel sheet sheet pile having joints at both ends. In addition, the joint shape is not only the integrally formed one that is often used for steel sheet piles, but also the type in which slit pipes welded to the ends of steel elements are fitted together, and a male pipe with a T-shaped cross section using the slit pipe as a female joint. There is no particular limitation on the type in which a joint is fitted. Further, the fitting portion is subjected to grout injection or the like to prevent concrete or the like from flowing out. If the tubular structure is constructed underground, such as deep foundation piles or vertical shafts, install a cutting edge hardware at the lower end,
Unit-closed cells are successively added while being pressed into the ground,
It will be sunk to a specified depth by excavation inside. Depending on the construction conditions, etc., concrete can be poured into the double steel shell after adding multiple unit closing cells, but concrete filling and curing should be performed every time a unit closing cell is formed. Done, and with some strength developed,
If the following unit closed cells are added, construction can be performed in a structurally stable state during construction. It is also possible to perform concrete curing and joining of unit closed cells in parallel. In particular, when constructing the tubular structure in the ground, it is preferable to fill the concrete each time the unit closed cell is formed.

[0006]

According to the construction method of the present invention, the parallel-flange steel elements having joints at both ends are staggered in a zigzag manner and the unit-closing cells formed by joint-fitting are successively added. A high-strength, high-rigidity cylindrical structure because the joining positions of cells are discontinuous and concrete is filled in the cylindrical or prismatic double steel shell constructed in this way to combine and integrate them. Can be easily constructed.

The steel element used in the construction method of the present invention is divided into small pieces, is excellent in handleability, and is joined in a joint fitting type similar to that of conventional steel sheet piles. Easy and reliable. The steel element has excellent transportability and uses a high-strength, high-quality steel element manufactured in the factory, and by filling concrete, a highly reliable tubular structure can be constructed as a steel-concrete composite structure. . A unit closed cell in which the steel elements are staggered and the upper and lower ends are serrated.
By sequentially repeating the process of adding the unit closed cells to the upper side while press-fitting into the ground, it is possible to construct a tubular underground structure having high strength and high rigidity. Further, by filling the concrete every time the unit closed cells are formed, it is possible to construct in a structurally stable state.

[0008]

1 to 3 show, as an example of a cylindrical structure constructed according to the present invention, a completed state of a shaft provided in the ground. Reference numeral 7 in the drawing denotes a cutting edge metal fitting for press-fitting the structure into the ground, and a steel element 3 forming a double steel shell is sequentially fitted onto the cutting edge metal fitting 7 to form a unit. The closed cell 2 is formed. 5 in the figure
Indicates a vertical joint by the joint 3C. The upper ends of the unit closed cells 2 are staggered with respect to the adjacent steel elements 3 so that the horizontal joint portion 6 with the unit closed cells 2 added to the upper side is discontinuous. Concrete 4 is filled in the double steel shell by the steel element 3 closed in a cylindrical shape, and by solidifying the concrete 4, an integral tubular structure 1 of a steel concrete composite structure is formed.

FIG. 4 shows a steel element 3 used in the present invention.
In this example, a rectangular steel pipe 3A is used as the main body of the steel element 3, and a half-cut body 3b of a steel sheet pile having a joint 3C is arranged parallel to the four corners of the rectangular steel pipe 3A and welded. .

FIG. 5 partially shows a state in which the steel element 3 of FIG. 4 is connected in a cylindrical shape to form a unit closed cell 2 having a double steel shell structure and concrete 4 is filled inside. After pouring grout into the gap of the joint 3C, the concrete 4 is filled.

FIGS. 6 to 13 show an example of a construction procedure according to the method for constructing a tubular structure of the present invention. The construction is carried out in the following steps. Preparatory work (ground anchor, installation of cutting edge hardware) [Refer to FIG. 6] The ground anchor 11 for taking a reaction force of press-fitting is installed at a cylindrical structure building position as a vertical shaft. The cutting edge hardware 7 is installed on the ground portion, and the temporary frame 12 is assembled thereon.

Element installation, closing, shaping, temporary welding (see FIG. 7) Using the temporary frame 12, the steel element 3 is sequentially manufactured.
Are assembled while fitting the adjacent steel element 3 and the joints 3C. The steel elements 3 are arranged in a zigzag pattern so that the upper ends of the steel elements 3 are sawtooth. The closed cells 2 at the lowermost end and the uppermost end are staggered by alternately arranging steel elements 3 having different lengths. Further, the joint 3C portion is tack welded.

Joint seal (grouting) [Fig. 8
Reference] Grouting is performed in the gap between the fittings 3C fitted together, and the fitting is sealed.

Concrete pouring in element partition wall (see FIG. 9) Concrete 4 (see FIG. 5) is placed in a double steel shell by steel elements 3 closed in a cylindrical shape, and curing of concrete 4 (1 day ) After that, the temporary frame 12 (FIGS. 1 to 3,
(See Fig. 4).

Installation of press-fit loading device (see FIG. 10) A unit closing cell is installed by installing a reaction force frame 13 on the upper end of the unit closing cell 2 and excavating the inside thereof, and by using a center hole jack 14 which takes a reaction force to the earth anchor 11. Press 2 into the ground.

Element building, closing, shaping, temporary welding (second step) [see FIG. 11] A unit in which the temporary frame 12 is assembled and the steel element 3 is built in the same manner as the above process and press-fitted into the ground. A new unit closed cell 2 is joined to the upper side of the closed cell 2.

Repeating the Steps (Refer to FIG. 12) The above steps (1) to (2) are repeated to sequentially form the cylindrical structure and press-fit it into the ground. In the figure, 15 indicates a bucket for internal excavation.

Pouring of bottom concrete, completion of interior work (see FIG. 13) After the tubular structure 1 is completed by performing a predetermined depth, an underwater concrete 16 is placed at the tip, and the bottom concrete 17 is placed on it. Construct.

[0019]

According to the construction method of the present invention, the unit closed cell 2 in which the steel elements 3 are staggered and the joints 3C are fitted thereinto
By sequentially adding and filling the interior with concrete 4 to join and integrate it as a steel-concrete composite structure, it is possible to easily construct a high-strength, high-rigidity tubular structure in which the joint portion does not become a weak point. . Since the steel elements 3 that are divided into small pieces are used for joining in a joint-fitting type, the handling is excellent and the joining work is easy. Also in the case of an underground structure, a high-strength, high-rigidity cylindrical underground structure can be constructed with good workability and at low cost. By filling the concrete 4 each time the unit closed cells 2 are formed, construction can be performed in a structurally stable state.

[Brief description of drawings]

FIG. 1 is a plan view showing a tubular structure constructed by carrying out the present invention.

FIG. 2 is a side view of the tubular structure shown in FIG.

FIG. 3 is a vertical cross-sectional view of the tubular structure shown in FIG.

FIG. 4 is a plan view showing an example of a steel element used in the present invention.

FIG. 5 is a horizontal cross-sectional view showing a part of a tubular structure constructed using the steel element of FIG.

FIG. 6 is a vertical sectional view showing a construction procedure in one embodiment of the present invention.

7 is a vertical cross-sectional view showing a construction procedure following FIG.

FIG. 8 is a vertical cross-sectional view showing a construction procedure following FIG.

9 is a vertical cross-sectional view showing a construction procedure following FIG.

FIG. 10 is a vertical cross-sectional view showing a construction procedure subsequent to FIG.

11 is a vertical cross-sectional view showing a construction procedure following FIG.

12 is a vertical cross-sectional view showing a construction procedure following FIG.

13 is a vertical cross-sectional view showing a construction procedure following FIG.

FIG. 14 is a front view (partially sectional view) showing an example of a conventional tubular structure used for a bridge substructure.

FIG. 15 is a perspective view showing a conventional example of a tubular structure made of concrete segments.

[Explanation of symbols]

 1 Cylindrical structure 2 Unit closed cell 3 Steel element 3A Square steel pipe 3B Steel sheet pile half-cut body 3C Joint 4 Concrete 5 Vertical direct joint 6 Horizontal joint 7 Cutting edge hardware 11 Earth anchor 12 Temporary frame 13 Reaction frame 14 Center hole jack 15 Bucket 16 Underwater concrete 17 Bottom concrete

Claims (3)

[Claims] 1. A parallel flange steel element 3 having joints 3C at both ends is joint-fitted to form a unit closed cell 2 of a double steel shell structure of a cylindrical shape or a rectangular tube shape, and the double steel shell. In the method for constructing a tubular structure in which concrete 4 is filled into a steel-concrete composite structure, adjacent steel elements 3 are vertically staggered in a zigzag manner, and the joints are fitted to each other. Serrated unit closed cell 2
And a unitary closed cell 2 is added to the upper side one by one, and the cylindrical structure is constructed. 2. The method for constructing a tubular structure according to claim 1, wherein the unit closed cells 2 having upper and lower ends having a serrated shape are successively inserted into the ground while the unit closed cells 2 are added to the upper side. 3. The unit closed cell 2 is formed, and then the double steel shell of the unit closed cell 2 is filled with concrete 4 and solidified, and the unit closed cell 2 is sequentially added to the upper side. Alternatively, the method of constructing the tubular structure of item 2.