JPH0463170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for converting a pretension type centrifugal prestressed concrete pile from an upper pile or a middle pile to a lower pile.

<Prior Art> When the ground that supports the load of the superstructure is located deep underground, a plurality of piles are connected and driven into the ground.

The lengths of the lower pile that will be the lowest layer, the upper layer that will be the top layer, and the middle pile that is connected between the upper and lower piles are set in advance, but they can be adjusted at the site according to the actual geological conditions. Often changed. When the length of the lower pile is changed, it is difficult to obtain the lower pile of the changed length, and it is easy to obtain the upper pile or middle pile of the length that matches the changed length of the lower pile. , use upper or middle piles converted to lower piles.

First conventional example: When converting an upper pile or middle pile into a lower pile on site, a driving shoe is overlapped with the end plate of one end of the upper pile or middle pile lying on the ground, and the upper pile or middle pile is driven. While rotating together with the shoe, the groove on the outer periphery of the end plate and the outer periphery of the driving shoe are welded to fix the driving shoe to the end plate.

2nd Conventional Example A method of converting an upper pile into a lower pile in a factory is as disclosed in Japanese Patent Application Laid-Open No. 58-29918.
Bolt a driving shoe to a specific end of the upper pile.

In this method, the upper pile has a thin end plate fixed to one end of the cylindrical concrete body,
A thick end plate is fixed to the other end, a PC steel wire is tensioned between both end plates, and a screw hole for tensioning the PC steel wire is left on the outer surface of the thin end plate, making it difficult to connect the outer circumference of the thick end plate. A groove is formed for this purpose.

The driving shoe is penetrated by a bolt hole that communicates with a screw hole in the thin end plate of the upper pile.

When converting an upper peg into a lower ply, screw the bolt inserted into the bolt hole of the driving shoe into the screw hole in the thin end plate of the upper ply, and then attach the driving shoe to the thin end plate of the upper peg. fix it with bolts.

<Problems to be Solved by the Invention> However, in the first conventional example, the welding of the driving shoe is carried out while rotating the pile lying on the ground on the pillow material, so a large work area and pillow material are required. It is. Further, welding of a driving shoe cannot be performed in bad weather or when close to flammable equipment.

A second conventional example is a method in which an upper pile is modified into a lower pile. Furthermore, one end plate of the pile is thin and does not have a groove for a tight connection, so it cannot be used as a center pile for connecting two pieces at both ends.
Therefore, it is not a method of converting a middle peg into a lower peg.

In addition, although the second conventional example is a method carried out in a factory, if it were to be carried out on site, the driving shoe would be fixed only to one end plate of the upper pile, that is, the thin end plate. When there is no working space for fixing the driving shoe on the thin end plate side of the upper pile lying on the ground at the site, the upper pile for the lower pile must be moved, which takes a lot of effort.

Furthermore, when a pile lying on the ground is lifted up on the ground by heavy equipment in order to be driven into the ground, the upper pile lifts the thin end plate side that will become the upper end, but the lower pile holds the driving shoe in place. Lift up the thick-walled end plate side opposite the thin-walled end plate side. Therefore, the lifting ends of the upper and lower piles are opposite, so if there is no large space for heavy machinery on both end plates of the upper piles that are lined up on the ground, the upper pile for the lower pile should be used. The direction must be reversed, which takes a lot of effort.

In the end, in both the first conventional example and the second conventional example, it is not easy to convert an upper pile or a middle pile into a lower pile on site.

An object of the present invention is to solve the conventional problems as described above.

<Means for Solving the Problems> The present invention provides a method for fixing a driving shoe to one end of an upper pile or a middle pile of a pretension type centrifugal prestressed concrete pile and converting the upper pile or middle pile into a lower pile. , Top piles and medium piles have circular plate-shaped end plates fixed to both ends of a cylindrical concrete body, a PC steel wire is tensioned between both end plates, and an opening for connecting the piles is provided on the outer periphery of each end plate. A tip is formed, and a screw hole for tensioning the PC steel wire remains on the outer surface of both end plates, and a bolt hole that communicates with the screw hole in the end plate of the upper or middle pile passes through the driving shoe. Then, screw the bolts inserted into the bolt holes of the driving shoe into the screw holes in one of the end plates of the upper pile or the screw holes in the end plate of one of the middle piles. This is a method of converting a top pile or a middle pile into a bottom pile, which is characterized by fixing a driving shoe to one end plate or one end plate of the middle pile with bolts.

<Function> In the present invention, a driving shoe is fixed with a bolt to either one of the end plates of the upper pile or one of the end plates of the middle pile, and the upper pile or the middle pile is converted into a lower pile. .

<Effects of the Invention> In the present invention, since the driving shoe is fixed with bolts, there is no drawback due to welding as in the first conventional example in which the driving shoe is welded, and the driving shoe can be easily fixed. be.

Further, unlike the second conventional example in which the upper pile is modified into a lower pile, not only the upper pile but also the middle pile is converted into a lower pile.

Furthermore, since the driving shoe is fixed to either end plate of the upper pile, unlike the second conventional example in which the driving shoe is fixed to a specific end of the upper pile, it is possible to fix the driving shoe to either end plate of the upper pile lying on the ground. If there is a work place for fixing the driving shoe on the end side of the shaft, there is no need to move the upper peg for the lower ply.

Furthermore, if either end of the upper piles arranged in parallel on the ground is used for lifting heavy machinery, there is no need to reverse the direction of the upper piles for the lower piles.

After all, it is easy to convert an upper or middle pile into a lower pile on site.

<Example> In this example, as shown in FIG. 1, a driving shoe 15 is fixed to either one of the end plates 3 of the upper pile 1 or one of the end plates of the middle pile with bolts 17. This is a method of modifying the upper peg or middle peg into a lower peg.

The upper pile 1 and the middle pile have the same structure and are pretension type centrifugal prestressed concrete piles, and as partially shown in Figs. An end plate 3 of a circular plate-shaped steel plate is fixed, and a large number of PC steel wires 6 passing through the peripheral wall of the concrete body 2 are tensioned between both end plates 3.

As shown in FIGS. 1 and 4, a large number of steel wire insertion holes 4 pass through each end plate 3, and the end of each PC steel wire 6 is inserted into each steel wire insertion hole 4. , each PC
The riveted head-like end of the steel wire 6 is inserted into each steel wire insertion hole 4.
It is fitted into a counterbore.

The outer peripheries of both end plates 3 are marked with figures 1 and 4, respectively.
As shown in the figure, a groove portion 7 for connecting a stake is formed.

As shown in FIGS. 1 and 4, screw holes 5 for tensioning the PC steel wire, which were used when pretensioning the PC steel wire 6, penetrate through both end plates 3 at equally spaced positions. It remains.

As shown in FIGS. 1 and 4, the driving shoe 15 is an open, circular plate-shaped steel plate with an outer diameter slightly smaller than the outer diameter of the end plate 3 and an inner diameter smaller than the outer diameter of the end plate 3. A bolt hole 16 that is smaller than the inner diameter of the end plate 3 and inserted into each screw hole 5 of the end plate 3 passes through the end plate 3.

The method of this example is as shown in FIGS. 2 to 4.
The driving shoe 15 is concentrically overlapped with either the end plate 3 of the upper pile 1 or the end plate of the middle pile, and each bolt of the driving shoe 15 is inserted into each screw hole 5 of the end plate 3. The holes 16 are connected, each bolt 17 is inserted into each bolt hole 16, and each bolt 17 that has passed through the driving shoe 15 is screwed into the screw hole 5 of the end plate 3 and tightened. or one end plate 3
Or drive shoe 1 into the scrap material of either one of the medium piles.
5 is fixed with a large number of bolts 17.

In FIGS. 1 to 4, 18 is a reinforcing band.

The method of using the lower pile modified by the method of this example is the same as that of the conventional one.

<Modification> In the embodiment, the driving shoe 15 was of an open type, but it may be of a closed type.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a top screw, driving shoe, and bolt used in the method of the embodiment of the present invention. Second
The figure is a partial front view of a lower plinth modified by the method of the same example. FIG. 3 is a side view of a lower plinth modified by the same method. FIG. 4 is a sectional view taken along the - line in FIG. 3. 1: Top pile, 2: Concrete body, 3: End plate, 5: Screw hole, 6: PC steel wire, 7: Groove section, 1
5: Driving shoe, 16: Bolt hole, 17: Bolt.

Claims (1)

[Scope of Claims] 1. A method of fixing a driving shoe to one end of an upper pile or a middle pile of a pretension-type centrifugal prestressed concrete pile and converting the upper pile or middle pile into a lower pile, comprising: In this method, circular plate-shaped end plates are fixed to both ends of a cylindrical concrete body, a PC steel wire is tensioned between both end plates, and grooves for pile connection are formed on the outer periphery of both end plates. Screw holes for tensioning the PC steel wire remain on the outer surface of both end plates, and the bolt hole that communicates with the screw hole in the end plate of the upper or middle pile passes through the driving shoe. Screw the bolts inserted into the bolt holes of the driving shoe into the screw holes in one of the end plates of the upper peg or the screw holes in the end plate of either the upper peg. A method of converting a top or middle peg into a bottom peg, which comprises fixing a driving shoe to either end plate of the peg with bolts.