JPS6149022A - Concrete composite foundation pile - Google Patents

Abstract

PURPOSE:To easily manufacture a concrete composite foundation pile by a method in which plural parts counteracting the horizontal force are projectionally set along the inside axial direction of a thin steel plate cylinder, and a given thickness of concrete is packed into the inside of the cylinder to close both sides of the cylinder. CONSTITUTION:Horizontal force-counteracting parts 5 are welded at a given interval along the inside axial direction of a thin steel plate 1, and the steel plate 1 is bent into a cylinder 3. A latex 11 is coated on the inner surface of the cylinder 3 and a given thickness of concrete 7 is packed and hardened on the inner surface of the cylinder 3 by a centrifugal molding method. Weld couplers 9 are attached to both ends of the cylinder 3. A concrete composite foundation pile having excellent resistance to horizontal forces and excellent cohesion can thus be obtained at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to foundation piles for structures, and more particularly to concrete composite foundation piles.

[Prior art]

Conventionally, various types of foundation piles for structures have been proposed and widely used, such as concrete RC piles, PC piles, steel pipe piles, and even composite piles made of steel pipes filled with concrete.

By the way, among these types of foundation piles, concrete RC
Although piles are easy to manufacture and the advantages of concrete, which has high compressive force, can be effectively used as support for piles, they have the disadvantage that they are weak against bending and are prone to cracking on the pile surface (concrete surface). The occurrence of these cracks not only makes it easier for buckling to occur in those areas, but also causes the internal reinforcing bars to corrode due to the intrusion of groundwater, eventually causing the pile to lose its function.

Therefore, a PC pile with prestressed concrete has been proposed, but since this PC pile lacks viscosity, if bending stress exceeding a certain level is applied, the PC steel wire will break, rendering the prestressing pointless. There is a problem.

In response to these problems with concrete piles, steel pipe piles are superior to concrete piles because they have elasticity themselves and have sufficient horizontal force in addition to bearing capacity. In addition to the problem that the wall thickness of steel pipes is regulated by JTS and the manufacturing cost is high, it is also necessary to take measures to prevent corrosion due to the effects of underground water and acidic soil. In addition, in the case of composite piles in which gAg is buried and then concrete is filled inside, in addition to the above-mentioned corrosion problem, it is not only necessary to cut the pile cap after the pile driving work is completed, but this work also causes the concrete to deteriorate. There were drawbacks such as the crystal structure being destroyed.

In order to overcome these drawbacks of foundation piles, the inventor conducted intensive research and repeatedly produced prototypes. As a result, the inventor focused on the fact that improvements in coating technology had reduced the requirements for corrosion of steel pipes in the earthquake-resistant foundation structure design standards. By processing a steel plate into a cylindrical shape, providing a plurality of horizontal force resisting members on the inside of this cylindrical body, filling it with concrete by centrifugal forming, and closing both ends of this cylindrical body with welded joints. It was discovered that it is possible to obtain concrete composite foundation piles that are low in manufacturing cost and have sufficient horizontal force and excellent viscosity similar to steel pipe piles.

[Purpose of the invention]

An object of the present invention is to provide a concrete composite foundation pile that is easy to manufacture, has excellent viscosity, and is inexpensive.

[Key points of the invention]

The concrete composite foundation pile according to the present invention includes a cylindrical body formed by bending a thin steel plate, a plurality of horizontal force resisting members protruding along the axial direction of the inner surface of the cylindrical body, and the cylindrical body It is characterized in that the inner surface of the main body is filled with concrete of a predetermined thickness, and both ends of the cylindrical main body are closed with welded joints.

In this concrete composite foundation pile, the horizontal force counter member can be provided over the entire length of the inner surface of the cylindrical body, or can be placed at an appropriate distance on the inner surface, and furthermore, it can strengthen the adhesion between the inner surface and the concrete. It is suitable if a material is provided.

〔Example〕

Next, preferred embodiments of the concrete composite foundation pile according to the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2, the concrete composite foundation pile according to the present invention has a wall thickness of, for example, 1.6 mm or 2.6 mm.
A cylindrical main body 3 of a predetermined length is formed using a thin steel plate 1 set to about 3 m+u, and a plurality of horizontal holes are formed on the inner surface of the cylindrical main body 3 along the axial direction and extending over the entire length of the cylindrical main body 3. A force countering member 5 is provided, the inside of the cylindrical body 3 is filled with concrete 7 of a predetermined thickness with a minimum guaranteed strength of 850 kg/cnT or more, and both ends of the cylindrical body 3 are welded together with welded joints 9.9. Consists of occlusion.

In this case, the outer surface of the cylindrical body 3 is coated with a corrosion-resistant coating (not shown) by an appropriate means, and the inner surface is provided with an adhesion-strengthening material 11 made of latex or the like, so that the concrete can be bonded. 7 cylindrical body 3
It is preferable to configure the structure so that the adhesion to the material is strong.

In addition, this concrete composite foundation pile is manufactured by cutting the thin steel plate 1 according to the external shape of the foundation pile (see Fig. 3a), and then cutting the thin steel plate 1 into round steel, flat steel, and angle steel along the longitudinal direction of the inner surface of the thin steel plate 1. (see Figure 3b), and then weld these horizontal force countering members 5 at predetermined intervals.
The cylindrical main body 3 is formed by bending the welded thin steel plate 1 and welding the opposing side edges to each other.
(see figure), latex 11 is applied to the inner surface of this cylindrical body 3.
The concrete 7 of a predetermined thickness is applied and hardened by centrifugal molding (see Figure 3d), and the welded joints 9.9 are attached to both ends of the cylindrical body 30, and then processed to the appropriate design length. (See Figure 3e). In this case, the horizontal force resisting member 5 can also be formed of shaped steel ribs 12 welded at predetermined intervals along the longitudinal direction of the inner surface of the thin steel plate 1, as shown in FIG.

〔Effect of the invention〕

As mentioned above, according to the concrete composite pile according to the present invention, the concrete 1 is centrifugally formed inside the cylindrical body.
・Since we adopted a configuration in which horizontal force countering members provided integrally with the inner side surface of this cylindrical body are arranged at predetermined intervals in the radial direction within the cross section, the cylindrical body and the horizontal force countering members are able to resist horizontal force. Since both of the piles work together to resist, it is possible to obtain horizontal force and viscosity comparable to that of conventional steel pipe piles.

Furthermore, since an adhesion-strengthening material is provided between the concrete and the inner side surface of the cylindrical body, it not only improves the function as a composite pile but also prevents cracks on the concrete surface.

Furthermore, the structure is simple, so it can be manufactured easily and inexpensively, and unlike conventional composite piles, which are made by burying steel pipes and then filling the inside with concrete, there is no need to cut the head of the pile, which shortens the pile driving period. It has various advantages such as:

Although the preferred embodiment of the concrete composite foundation pile according to the present invention has been described above, the present invention is not limited to this embodiment. Within the scope of the spirit of the present invention, the cylindrical body may be formed into a corrugated shape to further strengthen the adhesion between the concrete and the cylindrical body, or irregularities of an appropriate shape may be formed in the axial direction. Of course, various design changes may be made within the structure.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional explanatory diagram showing a preferred embodiment of the concrete composite foundation pile according to the present invention, Fig. 2 is a longitudinal sectional view of the concrete composite foundation pile shown in Fig. 1, and Figs. 3a to 3e are FIG. 4 is an explanatory diagram showing an example of the manufacturing method of the concrete composite foundation pile shown in FIG. 1, and FIG. 4 is an explanatory diagram showing another embodiment of the horizontal force countering member in the concrete composite foundation pile shown in FIG. 1. 1... Thin steel plate, 3... Cylindrical body, 5
... Horizontal force counter member, 7 ... Concrete, 9 ... Welded joint, 11 ... Adhesion reinforcement material, 12 ... Type Steel rib patent applicant Kodama Concrete Industries Co., Ltd. Patent attorney Takeshi
1) Ken City Procedural Amendments dated October 3, 1982

Claims (4)

[Claims] (1) A cylindrical body is formed by bending a thin steel plate, a plurality of horizontal force resisting members are protruded along the axial direction of the inner surface of the cylindrical body, and a predetermined thickness is provided on the inner surface of the cylindrical body. 1. A concrete composite foundation pile, characterized in that the cylindrical body is filled with concrete, and both ends of the cylindrical body are closed with welded joints. (2) The concrete composite foundation pile according to claim 1, wherein the horizontal force counter member is provided over the entire length of the inner surface of the cylindrical body. (3) The concrete composite foundation pile according to claim 1, wherein the horizontal force counter members are spaced apart from each other on the inner surface of the cylindrical body. (4) The concrete composite foundation pile according to any one of claims 1 to 3, which comprises providing an adhesion reinforcing material between the inner surface of the cylindrical body and the concrete.