JP2568982B2 - Foundation pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation pile attached to a tip of a steel pile serving as a foundation of a building.

[0002]

2. Description of the Related Art Conventionally, as a result of a geological investigation, a steel pile forming a foundation of a building has been driven in different geometries depending on the geology in which the rock to be the supporting layer is deep and the rock in which the rock is shallow. In other words, in geology where the depth up to the bedrock that becomes the support layer is deep, a cylindrical steel pile is driven into the ground with a pile hammer called, for example, a drop hammer, and the penetration amount due to hammering is measured to reach the bedrock. Even without this, the driving was finished at a position where it was judged that the building could be supported by friction between the peripheral surface of the steel pile and the stratum in contact with it. On the other hand, in a relatively shallow place of the bedrock serving as the support layer, the steel pile was driven, and the driving could be completed at a position where the bed reached the bedrock.

[0003]

[Problems to be solved by the invention]
In order to obtain a sufficient frictional force (surface) between the surface of the steel pile and the clay layer, it is necessary to add a large number of steel piles to obtain a large surface area, which complicates work and construction costs. Also had the disadvantage of becoming larger. In addition, there was no means to deal with the secular change of the stratum due to the change of groundwater flow. The present invention has been made in view of the above circumstances, and its purpose is to increase the building support of a steel pile supported by a clay layer or the like by frictional force, and to be supported by a support layer. The aim is to provide foundation piles to increase the bearing capacity of steel piles. Further, it is for increasing the supporting force of the steel pile driven into the supporting layer.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided an outer cylinder having the same diameter as the outer diameter of a steel pile, an inner cylinder provided concentrically within the outer cylinder, and an inner cylinder. A pressing element that can move up and down in the cylinder and whose tip is formed in a polygonal pyramid or conical shape, and a plurality of pieces that are supported by the tip of the outer cylinder and project radially from the opening of the outer cylinder by the pressing of the pressing element. Ri Do and a number of projecting pile, projecting outside the Dekui (6) is the outer tube (3)
It has an outer circumference equal to the circumference, and a convex portion (1
Has an inclined surface (17) for abutting the 4) is achieved by foundation piles, wherein Rukoto. Here, the polygonal pyramid-shaped pressing element includes a quadrangular pyramid, a hexagonal pyramid, an octagonal pyramid, and the like.

[0005]

[Operation] The foundation pile of the present invention configured as described above is
After being attached to the tip of the steel pile and driven into the ground and stopped driving at the position supported by the friction force, applying a pressing force from above to the pressing element provided in the inner cylinder, the outer cylinder and The projecting pile supported by the inner cylinder is projected radially from the opening of the outer cylinder by the polygonal taper surface of the pressing element and cuts into the geology around the outer cylinder, improving the stability of the foundation pile supporting force. , Increase support.

[0006]

1 to 10 show an embodiment of the present invention.
This will be described in detail with reference to FIG. In FIG. 1, a foundation pile 1 is formed of a steel outer cylinder 3 having the same outer diameter as the outer diameter of a steel pile 2 driven into the ground, and is formed concentrically with the outer cylinder in the outer cylinder 3. A steel inner cylinder 4, a presser 5 provided in the inner cylinder 4, which can move up and down freely by using an inner peripheral surface of the inner cylinder 4 as a guide, and a bottom part of the inner cylinder 4 and the outer cylinder 3. And a plurality of projecting piles 6 which are supported by the bottom and project radially outward from the opening 8 of the outer cylinder 3 by the downward pressing of the pressing element 5.

[0007] The outer cylinder 3 is a steel cylindrical member similar to the steel pile 2, and has a connection member 7 provided on the inside of the upper part by welding and fixed to the steel pile 2, and an opening for projecting the projecting pile 6 around the lower part. 8 are provided at a plurality of locations (eight locations at equal intervals in FIG. 2). Each of the openings 8 is formed in a shape of a cutout from the peripheral surface of the lower end of the outer cylinder 3, and has a substantially square shape when viewed from the front as shown in FIG. 4. A bottom plate 10 provided with an opening 9 equal to the inner diameter of the inner tube 4 described later is provided on the lower end surface of the outer tube 3 provided with the opening 8, and the opening 9 has a thickness smaller than the bottom plate 10. Of the outer cylinder 3 is provided on the bottom plate 10
And the lid member 11.

The inner cylinder 4 is a steel cylindrical member provided at a predetermined distance from the inner peripheral surface of the outer cylinder 3.
A support plate 12 formed in the shape of a flange is provided on the lower end surface of the cover. The outer periphery of the support plate 12 is in close contact with the inner peripheral surface of the outer cylinder 3.
It is attached to the upper side. A holding plate 13 is provided on the outer peripheral surface of the upper part of the inner cylinder 4 for keeping the distance from the inner peripheral surface of the outer cylinder 3 constant.
And the inner cylinder 4 are fixed while maintaining a parallel state with each other. A presser 5 having a diameter slightly smaller than the diameter of the inner peripheral surface of the inner cylinder 4 is provided in the inner cylinder 4 so as to be vertically movable. The pressing member 5 is a steel cylindrical member having a polygonal pyramid-shaped convex portion 14 formed at the lower end thereof, and a cylindrical member 15 attached to the rear end of the pressing member 5. The pressing element 5 can be moved up and down via.

The projecting pile 6 is, as shown in FIGS.
The cylindrical member made of steel, which is equivalent to the height of the opening 8 formed in the outer cylinder 3, has a shape obtained by radially cutting a cylindrical member in the radial direction. Is formed, and the center hole 1 is formed.
6 has an inclined surface 17 equivalent to the inclination of the projection 14.
It has become. The outer circumference of the protruding pile 6 is formed to be equal to the outer circumference of the outer cylinder 3, and the right and left sides of the two adjacent sides of the protruding pile 6 that contact the outer peripheral side match the left and right widths of the opening 8. As shown in FIG. 2, the two adjacent sides that are radially in contact with each other by being brought close to the center portion side are brought into contact with each other and the support plate 12 of the inner cylinder 4 is formed on the bottom plate 10 of the outer cylinder 3. It is formed so as to be arranged on the lower side.

With respect to the arrangement of the projecting piles 6 described above, for example, when eight projecting piles 6 as shown in FIG. 2 are arranged between the opening 8 of the outer cylinder 3 and the projecting piles 6. , An isosceles triangular guide member 18 having an apex angle of, for example, 45 °
Are provided on the inner peripheral surface. The guide members 18 are configured so that the respective projecting piles 6 can project radially from the center hole 16. When the number of the protruding piles 6 is eight, the tip of the pressing element 5 has an octagonal pyramid shape, and the inclined surface of the pyramid is
In contact with the inclined surface 17. It is obvious that an inner tube 19 corresponding to the inner tube 4 is also provided on the steel pile 2 side on which the above-mentioned foundation pile 1 is mounted, and this inner tube 19 and the outer tube of the steel pile 2 are held. They are connected by a plate 13.

The foundation pile 1 constructed as described above is attached to the tip of the steel pile 2 and the steel pile 2 is driven by a pile driving machine (not shown), and the foundation pile 1 is driven to a predetermined position. 2 after stopping the driving of the cylindrical member 1 provided in the inner pipe 19 of the steel pile 2
By hitting No. 5, as shown in FIGS. 5 to 7,
The convex portion 14 at the tip of the conical pressing element 5 enters the central hole 16 formed by the projecting pile 6, and the polygonal pyramid slope formed by the projecting portion 14 contacts the inclined surface 17 provided at the rear of the projecting pile 6. 6 and 7, the projecting pile 6 is projected from the opening 8 of the outer cylinder 3 as shown in FIGS. This projection is performed by the guide member 18 so that the projecting stake 6 becomes radial. If the state shown in FIG. 6 continues to allow hitting, the state is continued until the state shown in FIG. 8 to FIG. Can be

FIGS. 8 to 10 show a state in which the convex portion 14 at the tip of the pressing element 5 has broken through the cover member 11 provided on the bottom plate 10 of the outer cylinder 3 and protrudes. The side portion of the protrusion 5 hits the rear end of the projecting pile 6, and the projecting portion of the projecting pile 6 projects outside the outer cylinder 3 and enters the stratum around the outer cylinder, so that the supporting force of the foundation pile 1 is significantly increased. Will be. In addition, even when the outer cylinder is around the rock, it can be digged into the rock, and the supporting force of the steel pile 2 can be strengthened.

As described above, in the above-described embodiment, eight projecting piles 6 are provided radially. However, the present invention is not limited to this, and the same effect can be obtained in the case of four or six. Needless to say, the pressing element 5 may have a polygonal pyramid shape. In the case of four, as shown in FIG.
The thickness (width direction) of one of the protruding piles 6 is increased, which has an effect on a strong formation or support layer. In this case, the different points are the thickness of the projecting pile 6 and the guide member 1.
8. Since the projecting pile 6 divides a disk member equal to the outer diameter of the outer cylinder 3 into four equal parts, the guide member 18 forms an isosceles triangle with a vertex angle of, for example, 90 °, but otherwise is the same as the above-described embodiment. is there. In the case of six, as shown in FIG.
The apex angle of the guide member 18 may be, for example, an isosceles triangle of 60 °. If the above alternative embodiments are properly used according to the geology, the fixing of the foundation pile 1 can improve the safety and obtain a high bearing capacity.

[0014]

As described above in detail, the foundation pile according to the present invention comprises an outer cylinder having the same diameter as the outer diameter of the steel pile, and an inner cylinder provided concentrically within the outer cylinder. At the end, a pressing element which is formed in a polygonal pyramid shape and which can move up and down is attached, and a protruding pile which can radially protrude outward from the opening of the outer cylinder by the pressing of the pressing element is provided . of
It has an outer circumference equal to the outer circumference and has
Has an inclined surface for contacting the convex part at the tip of the
When the protruding pile is pressed by the presser, the pressing force
It is evenly applied to the piles and the projecting piles can be driven into the ground smoothly.
It is easy and easy to carry out, and the projecting pile of the foundation pile of the present invention attached to the tip of the steel pile driven into the ground has a feature that the supporting force of the steel pile can be significantly increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of a foundation pile showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a front view of a main part as viewed from an arrow IV in FIG. 1;

FIG. 5 is a cross-sectional view showing a state in which the pressing element shown in the foundation pile of FIG. 1 is hit.

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is a front view of a main part as viewed in the direction of arrow VII in FIG.

FIG. 8 is a cross-sectional view showing a state where the presser shown in the foundation pile of FIG. 1 is pushed out to the maximum.

FIG. 9 is a sectional view taken along the line IX-IX of FIG. 8;

FIG. 10 is a front view of a main part as viewed from an arrow X in FIG. 8;

FIG. 11 is a sectional view showing a stored state and a projected state of a four-way projected pile of a foundation pile showing another embodiment of the present invention.

FIG. 12 is a sectional view showing a stored state and a protruding state of a six-direction protruding pile of a foundation pile showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation pile 2 Steel pile 3 Outer cylinder 4 Inner cylinder 5 Presser 6 Projection pile 7 Connection member 8 Opening 9 Opening 10 Bottom plate 11 Cover member 12 Support plate 13 Holding plate 14 Convex part 15 Column member 16 Center hole 17 Slope 18 Guide member 19 Inner tube

Claims (1)

(57) [Claims] 1. An outer cylinder (3) having the same diameter as an outer diameter of a steel pile (2), an inner cylinder (4) provided concentrically in the outer cylinder, and a vertical movement in the inner cylinder. A pressing element (5), the tip of which is formed in the shape of a polygonal pyramid or a cone, and which is supported by the tip of the outer cylinder and is projected radially from an opening (8) of the outer cylinder by the pressing of the pressing element. Ri Do from a plurality of projecting pile (6), projecting outer periphery of Dekui (6) is the outer tube (3)
(14) having an outer circumference equal to
Characterized that you have an inclined surface (17) for abutting the foundation pile (1).