JPH0551924A - Tip pile having laminated cloth cylinder - Google Patents

Abstract

PURPOSE:To heighten injecting pressure resistance and control a dehydrating quantity easily by injecting solidifying fluid into a laminated cloth cylinder with a laminated cloth sheet, fitted on the outer periphery of a prefabricated pile with upper and lower bands. CONSTITUTION:Cylindrical cloth body 2 put together with the 2-5 sheets of nylon or the like with sewn sections 5 to be shifted preferably so that it may not be overlaid, are fitted on the prefabricated pile 1 of a concrete pile or the like normally to be a pile at the lowest end, with the bands 4 of upper and lower packing band steels. Then, into the cloth shell bodies 2, the solidifying fluid 3 of cement milk or the like is injected, and with specified injecting pressure, water content in the fluid 3 is dehydrated through the surface of the cloth shell bodies 2, and an elaborate and strong hardened body is composed. As a result, even if a tensile force working on the diameters and sheets of the cloth shell bodies 2 gets great, and even if they have the sewn sections, they can resist high injecting pressure, and the dehydrating quantity can be easily controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prefabricated pile equipped with a cloth cylinder used for forming an enlarged portion by injecting cement milk, concrete or the like into a bag body mounted on the prefabricated pile. is there.

[0002]

2. Description of the Related Art Conventionally, ready-made piles having cloth cylinders have been developed in order to exert a high vertical supporting force. For example, Japanese Unexamined Patent Publication No. 61-122324 discloses a pile in which a cloth cylinder is attached to the outer periphery of the tip of a ready-made pile, but this pile has a predetermined depth in the soil previously excavated. After being embedded in the hole, the structure is such that a solidifying fluid such as cement milk under a certain pressure can be injected into the cloth cylinder through an injection pipe installed in the hollow part of the pile. In this pile,
As shown in FIG. 4, the cloth tubular body is formed by winding a single piece of cloth into a tubular shape to form a tubular body, or woven as a seamless tubular body from the beginning. The cloth tubular body is composed of a single piece of cloth, although most of the tubular body is doubled by folding the ends.

[0003]

However, in the above pile, the strength of the cloth cylinder is limited, and especially when the pile diameter becomes large and the cloth cylinder to be mounted also has a large diameter, Since the applied tension is large, there is a problem that the dough is broken by a relatively low injection pressure.
Further, when the cloth tubular body is not seamless and has a sewn portion, the strength of the sewn portion is lower by about 70 to 80% than the material strength, so that there is a problem that it breaks at a lower pressure. Furthermore, in order to control the amount of water dewatered from the cloth cylinder, a method of applying rubber coating to the cloth or impregnating it with a resin has been proposed, but it is not only time-consuming and costly. For this reason, it has not been put to practical use, and when the dehydration amount is large, the actual situation is to increase the injection amount of the caking fluid by that amount.

An object of the present invention is to provide a pile with a cloth cylinder body that can withstand a high injection pressure even if the diameter of the cloth cylinder body is large, and that can easily control the dehydration amount. ..

[0005]

DISCLOSURE OF THE INVENTION The present invention is a pile in which a cloth cylinder is attached to the outer periphery of a ready-made pile by a band at the upper and lower portions thereof, and the cloth cylinder is a multi-layered structure in which a plurality of fabrics are stacked. It is a tip pile characterized by having a structure. Hereinafter, description will be given with reference to the drawings.

FIG. 1 shows an example of a pile according to the present invention. A concrete cylinder pile is covered with a cloth cylinder 2 made by stacking a plurality of cloths, and the cloth cylinder 2 is fastened at its upper and lower ends with a band 4 to fix the cloth cylinder. It is a half cross-sectional view showing a state when a solidifying fluid 3 such as cement milk is press-fitted into the body. This pile is usually used as the bottommost pile. The ready-made pile 1 used in the present invention is a steel pipe pile, a concrete pile, a steel pipe concrete composite pile, or the like. The outer diameter of the ready-made pile is usually 30
It is 0 to 600 mmφ.

As shown in FIG. 1, in this pile, a cloth cylinder is attached to the outer peripheral surface of a ready-made pile by a band. The cloth cylinder used in the present invention has a cylindrical shape, and it is appropriate that the size thereof has a diameter of 500 to 1000 mm and a length of 1.5 to 3 m, and has a structure in which a plurality of fabrics are stacked. By superposing the dough in multiple layers in this way, it is possible to withstand a large injection pressure. The cloth tubular body may be formed by stacking a plurality of seamless and woven tubular cloths, or by stacking a plurality of cloths that are sewn by winding one cloth into a cylindrical shape. At this time, when a plurality of cylinders having the sewn portions 5 are stacked, it is necessary to shift the sewn portions so that they do not overlap each other as shown in FIG. The number of sheets to be stacked depends on the strength of the cloth, but normally 2 to 5 sheets are preferable. Further, if the value obtained by multiplying the fabric strength by the number of sheets is the same, it is preferable to stack 3 to 4 weak fabrics rather than stack 2 strong fabrics. By doing this, the decrease in strength of the sewn area will be reduced,
The dough strength can be effectively used. Further, it is preferable that both end portions of this cloth cylinder are contracted so that they can be evenly attached to a ready-made pile, tacked, and the contact portion with the band is further overlapped and reinforced. The material of the cloth cylinder is preferably synthetic fiber such as nylon, polyamide, polyester, vinylon, polypropylene, etc. from the viewpoint of dehydration property and strength of the caking fluid. When a material capable of discharging the water of the solidifying fluid is discharged to the outside as described above, the solidifying fluid such as cement milk is injected into the cloth cylinder of the pile body at the time of construction, and the predetermined pressure, for example, 6 to 10 kg /
The water in the caking fluid is dehydrated through the surface of the cloth cylinder by the injection pressure of cm ² , and the caking fluid becomes a dense and firm cured body after curing, which is preferable. At this time, if the amount of dehydration from the cloth cylinder is too large, the amount of dehydration can be easily reduced by stacking more fabrics.

The cloth cylinder is attached to the ready-made piles by the upper and lower sides of the band. An enlarged cross-sectional view of the cloth tubular body mounting portion A is shown in FIG. The band is usually made of packing steel strip or wire rope. The band is usually fixed with a tightening force of about 1 to 4 tons. In the case of packing strip steel, the width is 30 to 70 mm, and in the case of wire rope, the diameter is 10 to 10.
It is about 20 mm. Further, if the band is provided with protrusions 9 on the ready-made pile and fixed on both sides thereof, the mounting portion does not shift when the solidifying fluid is injected, so that it is safe.

Furthermore, if the cushion material 6 is arranged over the entire circumference between the cloth cylinder and the ready-made pile at the mounting portion, it is safe against leakage of the solidifying fluid. Examples of the material of the cushion material include foamed materials such as polyvinyl chloride, polyethylene, and polyurethane, and materials such as rubber that can close the gap between the cloth tubular body and the pile body after tightening the band. The width of the cushion material should be wider than the band,
It is preferably about 50 to 200 mm.

The pile also has an injection pipe 7 for injecting the solidifying fluid into the cloth cylinder. An iron pipe, a vinyl chloride pipe, or the like is used as the injection pipe. The injection pipe may be installed in the hollow part of the pile so that the tip is communicated with the cloth cylinder, or may be installed in the thick part of the pile.

[0011]

EXAMPLES The present invention will be described in detail below with reference to examples. The pile used in this example has the structure shown in FIG. As a ready-made pile, outer diameter 600 mmφ, wall thickness 90 mm,
A concrete pile having a length of 4 m was used. The outer circumference of this concrete pile was covered with a nylon cloth cylinder having an outer diameter of 900 mmφ and a length of 3 m, and both ends were fastened with a wire rope having a diameter of 10 mm with a force of about 1.5 ton and fixed with a wire clip 8. For the nylon cylinder, four layers of cloth having a tensile strength of 150 kg per 1 cm width were laminated. At this time, since the cloth tubular body had the sewn portions, the sewn portions were attached so as not to overlap each other. Also, both ends are tacked so that the diameter of the mounting part is 630
The structure is set to be mm. In addition, a cushioning material is placed between the concrete pile and the cloth cylinder to prevent the solidifying fluid from leaking during pouring, and a wire rope is placed on both sides with a protrusion to prevent the fitting portion from slipping. Tightened. Using this pile as the test body 1, cement milk was injected into the cloth cylinder on the ground to perform a pressure resistance test.

For comparison, a conventional pile, that is, a nylon tubular body having a tensile strength of 400 kg per 1 cm width was sewn into a tubular body, which was mounted on a concrete pile and tested. A pressure resistance test was performed on the body 2.
At this time, the dimensions of the concrete pile and the cloth cylinder of the test body 2 were exactly the same as those of the test body 1. As a result of this pressure resistance test, the test body 1 bursts at a pouring pressure of 12 kg / cm ² while the test body 2 bursts at a pouring pressure of 6 kg.
The sewn portion was broken at / cm ² . Further, while the dehydration amount of the test body 1 was about 10% of the injection amount of the caking fluid,
The dehydration amount of the test body 2 was about 30%, and it was confirmed that the injection amount of the test body 1 was small and it was economical.

[0013]

EFFECTS OF THE INVENTION The pile of the present invention has a structure as described above, and is high even if the diameter of the cloth cylinder becomes large and the tensile force acting on the cloth at the time of injecting the solidifying fluid becomes large. It is possible to withstand the injection pressure, and even if it has a sewn portion, it is possible to reduce the reduction in strength of the sewn portion. Further, it becomes easy to control the dehydration amount.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view when a caking fluid is injected into a cloth cylinder of a pile of the present invention to expand and expand a bag body.

FIG. 2 is a cross-sectional view taken along the line AA shown in FIG.

FIG. 3 is an enlarged cross-sectional view of a cloth tubular body mounting portion A shown in FIG.

FIG. 4 is a half cross-sectional view of a case where a solidifying fluid is injected into a conventional cloth cylinder of a pile to expand and expand the bag body.

[Explanation of symbols]

 1 Ready-made pile 2 Fabric cylinder 3 Solidifying fluid (bulb part) 4 Band 5 Sewing part 6 Cushion material, 7 Injection pipe 8 Wire clip 9 Protrusion 10 Friction cutter

Claims (1)

[Claims] 1. A cloth cylinder is a pile mounted on the outer periphery of a prefabricated pile by means of bands at the upper and lower parts thereof, and the cloth cylinder has a multi-layered structure in which a plurality of fabrics are stacked to form a fabric cylinder inside. A tip pile characterized by being provided with an injection pipe for communicating and injecting a caking fluid.