JPH09291528A - Steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of initial ground subsidence, and to improve the stability of the underground supporting force, and to facilitate the insertion into the hard ground by providing a bottom cover inside of a tip side of a steel pipe pile, which has a hollow cylindrical shape, at a constant depth for sealing, and providing a blade, which is projected from the tip of the steel pipe pile at an appropriate length, in the bottom cover. SOLUTION: A disc-shaped bottom cover 2 is welded to the inner peripheral surface of a main body 1 at an appropriate depth from an open tip of the hollow cylindrical main body 1, which is made of the structural carbon steel or the like and which is formed at the predetermined inner diameter and which has a constant strength. A blade 3, which has the predetermined height and which is made of high-tensile steel or the like, is welded to a lower surface of the bottom cover 2 so as to be vertically stood. Consequently, since a steel pipe pile having the bottom cover 2 is pressed into the ground, intrusion of the soil into the main body 1 is prevented by the bottom cover 2. With this structure, efficient press-in work can be realized without wasting the press-in work, and the generation of initial subsidence is prevented, and stability of underground supporting force is improved, and the stabilized supporting force can be showed for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile used to reinforce a ground portion which is a foundation of a civil engineering building.

[0002]

2. Description of the Related Art In civil engineering and construction work, it has long been recognized that the bearing capacity of a ground portion, which is the foundation of a building, is important, and steel pipe piles and the like have been used in order to obtain a high bearing capacity for the ground. Various methods of reinforcing the ground have been developed.

[0003] As a steel pipe pile or the like used in such a method of reinforcing the ground, for example, a steel pipe having an open straight shape as shown in FIG. 3 and which can be easily driven into the ground and is inexpensive. There is known a pile 100 or a screw steel pipe pile in which a blade 101A is provided at the tip portion as shown in FIG.

[0004]

However, when the former steel pipe pile is used, the long-term bearing capacity after casting is inferior.
In sandy ground, there are problems such as initial settlement likely to occur and unsuitability for placing on hard ground.

[0005] Further, if the screw steel pipe pile 101 is used, the production cost of the pile is high, the transportation and storage are troublesome, and the stratum near the tip of the steel pipe is roughened when the pile is penetrated, so that it is difficult to maintain the uprightness. There is a problem that the periphery of the pile is likely to sink.

[0006] In view of the above circumstances, the present invention has the advantage that the initial settlement is unlikely to occur, the bearing capacity in the soil is stable, the penetration into the hard ground is easy, and the transportation and
It is an object of the present invention to provide a steel pipe pile that is easy to store and work on site, and that can maintain the uprightness without roughening the formation around the tip of the steel pipe and can easily obtain the consolidation effect and accuracy.

[0007]

Means for Solving the Problems That is, the invention of claim 1 is:
A steel pipe pile having a hollow tubular shape, which is provided with a bottom lid at a certain depth inside the tip side of the steel pipe pile to close it, and a blade protruding from the tip of the steel pipe pile to the bottom lid by an appropriate length. Is provided.

[0008]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view of an essential part showing a steel pipe pile according to the present invention. This steel pipe pile is a body 1 having a hollow cylindrical shape (straight shape) having a constant strength, which is formed of an appropriate material, for example, a structural carbon steel or the like and has an inner diameter D.
And a disc-like shape having a diameter of approximately D welded to the inner peripheral surface of the main body 1 at an appropriate depth (depth D / 2 in this embodiment) from the open tip (lower end) of the main body 1. Of the bottom cover 2 and a predetermined height (for example, almost the same height as the inner diameter D of the main body 1 in this embodiment), and is formed of an appropriate material, for example, a material such as high tensile steel in this embodiment. The bottom cover 2 is provided with a blade 3 that is vertically welded to the lower surface of the bottom cover 2.

In this embodiment, the bottom cover 2 is provided at a depth (D / 2) which is half the inner diameter D of the body 1 of the steel pipe pile, and the height of the blade 3 is the same as the inner diameter dimension D. However, of course, it is not limited to these.

Therefore, according to this embodiment, since the steel pipe pile having the bottom cover 2 press-fits it into the ground, the soil does not enter the inside of the main body 1 from the bottom cover 2 and the efficient press-fitting action is achieved. Can be realized. Moreover, according to the steel pipe pile of this embodiment, the region indicated by the dot A in FIG. 2 is in a state where the soil is hard and compressed when the steel pipe pile is pressed in due to the consolidation effect, and due to the so-called Monroe effect, A region of compact soil spreads and swells below the blade 3, and the supporting force is further increased.

[0012]

As described above, according to the present invention, the bottom lid having the blade projecting inside the tip side (lower end) is provided. In other words, the bottom lid is provided at the tip portion and the tip portion is provided. Since it has a closed structure, there is no possibility that the soil will enter the inside of the pile even if it is press-fitted into the soil unlike conventional hollow steel pipe piles, so efficient press-fitting work with less waste of press-fitting action is possible. In addition to being realized, there is no risk of causing initial settlement, and since the bearing capacity in the soil is stable, it is possible to exert a stable bearing capacity for a long period of time.

Furthermore, according to the present invention, by press-fitting while rotating, even if the pressure input is small, the penetration can be performed extremely smoothly by the excavating effect of the blade protruding from the tip portion, so that it can be surely applied to the hard ground. It has the effect of being able to penetrate.

Further, according to the present invention, since there is no particular protruding portion on the peripheral surface portion, that is, since only a part of the blade projects from the tip surface, transportation, storage and on-site processing are easy. In addition, it is easy to maintain uprightness without roughening the stratum around the tip of the steel pipe, and it is possible to obtain the effect of consolidation and accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing a steel pipe pile used in the present invention.

FIG. 2 is an explanatory view showing a state when the steel pipe pile according to the present invention penetrates into the ground.

FIG. 3 is a schematic sectional view showing a conventional steel pipe pile.

FIG. 4 is a sectional view showing another steel pipe pile.

[Explanation of symbols]

 1 Main body 2 Bottom lid 3 Blade

Claims (1)

[Claims] 1. A steel pipe pile having a hollow tubular shape, wherein a bottom lid is provided at a predetermined depth inside the tip end of the steel pipe pile to close the steel pipe pile, and the bottom lid has an appropriate length from the tip of the steel pipe pile. A steel pipe pile characterized by having a blade that protrudes only a little.