JPH06108476A - Construction of stud in steel frame structure - Google Patents

Abstract

PURPOSE:To simplify the foundation structure without footing or horizontal beams, by excavating a hole in the foundation ground to insert a steel rod cage and directly burying the stud of a building on the ground at the head of concrete piles. CONSTITUTION:A hole is excavated in the foundation ground 1 to insert a steel rod cage with the enlarged head and concrete is placed to make a cast-in- place concrete pile 2. Next, the stud 61 of an upper structure 6 is buried on the enlarged head of the pile 2. And then finally concrete is placed to fix the stud. In this case, studs 61a are connected on the studs 61. The bending moment from the studs 61 is transmitted to the inside reinforcements of the enlarged head 21 through the concrete at the joint with the stud of the upper structure 6 on the pile 2 and hence, it is regarded as a fixed stud. In this way, the structure of foundation is simplified and the construction period is remarkably hastened and also the construction cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction method for constructing a simple structural steel structure on a foundation ground. More specifically, the pile head of a cast-in-place reinforced concrete pile is directly used as a foundation for a column base. A method of constructing a column base portion to be used.

[0002]

2. Description of the Related Art Conventionally, even in the case of constructing a building having a simple steel frame structure such as a multistory parking lot, as shown in FIG. 7, the procedure is basically the same as that of a full-scale building. After mounting the pile 2 on the foundation ground 1, forming the footing 53 on the pile head, and forming the foundation part by providing the foundation beam 55 connecting these as necessary, anchor bolts 54 are implanted in the foundation, Building 6 on the ground (above) on this anchor bolt
Is being built and fixed.

However, it is uneconomical to construct a foundation in the same procedure as a complicated structure, even if the structure is simple.
It was desired to simplify it. Generally, as foundation piles, those piles manufactured in factories such as PC piles and steel pipe piles that are generically referred to as ready-made piles are transported to the site and placed by a pile driver, and holes are excavated locally and There is a cast-in-place reinforced concrete pile that inserts a basket and pours concrete to form a pile.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to the case of an overhead object (ground building) having a small load and a simple structure,
It is an object of the present invention to provide a new construction method that simplifies the structure of the foundation part to speed up construction and reduce costs.

[0005]

[Means for Solving the Problems] The first aspect of the present invention relates to a pile head portion of a cast-in-place reinforced concrete pile, which is obtained by excavating a hole in a foundation ground, inserting a reinforcing cage, and placing concrete.
A method of constructing a column base portion of a steel structure, characterized in that the column base portion of a structure on the ground is directly embedded and fixed.
The present invention is the method for constructing a steel structure column base portion, wherein the pile head portion of a cast-in-place reinforced concrete pile is enlarged and formed so as to embed the steel structure column base portion.

[0006]

[Operation] Generally, as foundation piles, PC piles, which are generically called ready-made piles, and piles manufactured at steel pipe pile factories are transported to the site and placed by a pile driver, and holes are excavated at the site. , There is a cast-in-place reinforced concrete pile that forms a pile by inserting concrete by inserting a reinforced cage.

In the present invention, the pile head of the cast-in-place concrete pile is directly used as the foundation for the upper article, and the column base of the upper article is embedded in the pile head. By adopting this structure, footing and construction of horizontal beams are not required, and the construction is greatly simplified. At the connection between the pile and the column base of the upper structure, the bending moment from the column base is transmitted to the internal reinforcement of the pile head with an enlarged diameter through concrete, so it is used as a fixed leg instead of a pin. Since it can be handled, it is advantageous in design. In addition, the horizontal force during an earthquake can be borne by the rigidity of the soil part of the pile and the reaction force of the ground.

[0008]

【Example】

Embodiment 1 FIGS. 1 to 3 are sectional views sequentially illustrating a construction method according to an embodiment of the present invention. First, in FIG. 1, (1) When there is a concrete layer on the surface of the foundation ground 1,
First of all, the required portion is removed and the concrete layer is removed.

(2) Drilling of a hole is started by a drilling bucket. (3) Build a casing pipe and inject bentonite liquid according to the geology. (4) Excavate to a predetermined depth. (5) Pull up the bucket and measure the tip depth. (6) Wait for sedimentation of slime (held metal in the soil or organic suspended matter) and measure the amount of slime.

Next, as shown in FIG. 2, (7) The slime is discharged by a bucket with a rough bottom. (8) Measure the bottom depth of the hole after roughening the bottom. (9) Insert the rebar cage 22 into the hole. (10) Insert the Tremi tube, pour fresh concrete into the Tremi tube, and inject high-pressure water for 1-2 minutes.

(11) After the injection of high-pressure water is stopped, pouring of fresh concrete from the tremie pipe is started while raising the distance between the tremies. (12) Pull up the casing pipe after finishing pouring the concrete. As described above, the cast-in-place concrete pile 2 is formed. Next, in Fig. 3, (13) Excavate the ground surface by about 500 mm and mount the pile head.

(14) The height of the pile head is adjusted by mortar, the pillar core is marked out, and the anchor bolt is set in the mortar portion. (15) Build the steel member 6 and fully tighten the anchor bolts. (16) Build a reinforcing bar on the pile head 21 and set the formwork. (17) Pour concrete into the pile head 21 and assemble the superstructure.

(18) The whole surface is completed by backfilling the ground surface. Due to the above, cast-in-place concrete pile 2 and column base of top 6
61 and 61 are integrally connected, and a connection structure for transmitting load and moment is realized. Compared with the conventional construction method described above with reference to FIG. 3, not only the footing is not formed, but the construction is simplified, and the connection between the pile and the column base of the upper article is not a pin by design, Another advantage is that it can be handled as a fixed leg.

Second Embodiment A second embodiment of the present invention will be described with reference to FIGS. Figure 4
Is a front view showing an upper object used in this embodiment, 6 is a steel structure which is an upper object, 61 is a column base portion of which is a 300 × 300 square steel pipe, and 61a is a planted portion in the column base portion. With the studs
The length of the tip is 1000 mm and the diameter is 16 mm and the height is 80 mm. Fig. 5 is a front view of the pile. 2 is a pile with a diameter of 600 mm, 21 is a pile head with a diameter of 800 mm.
, Length 1000mm, 22 are reinforced cages, 16 longitudinal main bars 22a have a diameter of 19mm, hoops 22b have a diameter of 13mm, and pitch is 100mm at the pile head.

In this embodiment, unlike the first embodiment, the upper end portion of the reinforcing steel cage is enlarged and formed as described above, and the leg portion 61 of the upper object is inserted in this enlarged portion. When the last part of the concrete piling of the pile is constructed, the leg portion 61 is fixed to the pile head portion 21 through the concrete, and a connection structure similar to that of the first embodiment is realized. Figure 6 shows the front view of the completed state
A sectional view taken along the line AA is also shown in FIG.
Shown in. An enlarged diameter portion of the pile head 21 is formed near the surface of the foundation ground 1.

[0016]

According to the present invention, for an upper structure (ground structure) of a steel frame structure having a small load and a simple structure, the structure of the foundation portion is simplified, and the construction speed and cost are significantly reduced. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first stage of an example of a construction procedure of the present invention.

FIG. 2 is a sectional view showing a second stage of an example of the construction procedure of the present invention.

FIG. 3 is a sectional view showing a third step of an example of the construction procedure of the present invention.

FIG. 4 is a front view showing a steel frame structure according to a second embodiment of the present invention.

FIG. 5 is a front view showing a pile and a reinforcing bar car according to a second embodiment of the present invention.

FIG. 6 is a front view showing a connection structure in a second embodiment of the present invention and a sectional view taken along the line AA.

FIG. 7 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

 1 Foundation ground 2 Cast-in-place pile 21 Pile head 22 Reinforcing cage 6 Upper object 61 Column base 61a Stud 53 Footing 54 Anchor bolt 55 Horizontal beam

Claims (2)

[Claims] 1. A column base of a ground structure is directly embedded and fixed to a pile head of a cast-in-place reinforced concrete pile in which a hole is excavated in the foundation ground, a reinforced cage is inserted, and concrete is placed. A method of constructing a column base portion of a steel structure characterized by the above. 2. The method for constructing a column base portion of a steel structure structure according to claim 1, wherein the pile head portion of the cast-in-place reinforced concrete pile is enlarged and formed so as to embed the column base portion of the steel structure structure.