JPS6115209B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for constructing ready-made foundation piles, and in particular to a method for constructing ready-made foundation piles that is sunk in a site by a hollow digging method, and its purpose is to reduce friction between the pile and the soil during the construction process. The object of the present invention is to provide a construction method that facilitates the installation by reducing the frictional force, and prevents the reduction of the frictional force after the installation, and even improves the frictional force.

A method for constructing foundation piles without vibration or noise is the hollow construction method using ready-made piles. By the way, when burying piles in the hollow excavation method, an auger is inserted into the hollow part of the ready-made pile, and the soil is discharged from the tip.
Furthermore, a friction cutter having a diameter larger than the outer diameter of the pile body is provided at the tip of the ready-made pile, thereby reducing frictional resistance during sinking. Therefore, a void layer is formed around the stiffness. It is not preferable to leave this void layer as it is after the pile installation is completed. In other words, since the medium excavation method removes the ground equivalent to the volume of the pile, it does not compact the difficult surrounding ground like the percussion method, and it takes a considerable amount of time for the ground to recover and fill the void layer. . Therefore, the positive frictional force generated on the circumferential surface of the pile against the vertical load is small, and most of the vertical load reaches the ground at the tip of the pile, resulting in a relatively small vertical yield strength, resulting in an uneconomical design.

The present invention is a foundation pile and its construction method developed to solve the above-mentioned conventional problems, and the details thereof will be explained below using examples.

A friction cutter part 2 is formed at the tip of the hollow pile body 1 to have a diameter larger than that of the body 1. A conduit 3 is also attached along the body 1 by a band 4. At the tip of this conduit 3, a conduit ring 5 surrounding the main body 1 is provided at a stepped portion immediately above the friction cutter portion 2 between the friction cutter and the stake body. The conduit ring 5 is provided with a large number of upwardly directed spout ports 6 for grouting material, etc.

During construction, piles are erected on the required ground, an auger (not shown) is inserted into the middle of the pile, and the soil below the tip of the pile is excavated. Let it sink to the top. During the sinking operation, the conduit 3,
Air, water, or slow-hardening grout is jetted out from the spout 6 through the conduit ring 5 to completely cut off the frictional resistance between the entire circumferential surface of the main body 1 and the soil. If air or water is blown out during the pile-sinking operation, grout is injected again from the spout 6 after the pile is set, and fills the void layer A between the pile and the soil. When the filled grout material hardens, it becomes integrated with the soil, increasing the support capacity of the piles.

As the grouting material, cement milk, water glass, a mixture thereof, and other ground hardening materials are used.

This invention has the above-mentioned structure, and during the work of sinking a pile, air, water, or unhardened grout is spouted upward from the friction cutter part along the outer circumferential surface of the pile, thereby separating the pile from the soil. It can reduce friction and make it easier to sink piles. After the pile is sunk, the void layer between the pile and the soil is filled with grout, which hardens and becomes integrated with the soil, increasing the vertical bearing capacity of the pile. In addition, the amount of grout material is sufficient to fill the void layer between the friction cutter part and the pile body, so it requires a smaller amount than the pre-boring cement milk method, which is economical and reduces secondary pollution caused by muddy water. No outbreak.

Furthermore, since the grout conduit is installed along the pile, only one conduit is required and the conventional pile can be used as is, and since the conduit is provided on the outer surface of the pile, it is easy to insert the auger of the hollow digging method. be.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a pile used in the present invention, and FIG. 2 is a cross-sectional view of the pile used in the construction state. DESCRIPTION OF SYMBOLS 1...Piece main body, 2...Friction cutter part, 3... Conduit, 4... Band, 5... Conduit ring, 6... Spout, A... Void layer.

Claims (1)

[Scope of Claims] 1. A friction cutter portion having a larger diameter than the main body of the ready-made hollow pile is provided, and a conduit is attached along the main body of the hollow pile, and a large number of upwardly facing parts surrounding the main body of the conduit are provided. A foundation pile comprising a conduit ring having a spout formed therein and connected to a stepped portion between the friction cutter portion and the pile body. 2 At the lowest part, a friction cutter part with a larger diameter than the main body of the existing hollow pile is installed, and a conduit is installed along the main body of the hollow pile, and a large number of upward spouting ports are installed around the main body of the conduit. As a ready-made hollow pile, a conduit ring with a perforated pipe is connected to the stepped part between the friction cutter part and the pile body. The cutter part cuts the friction between the pile and the soil, and during the digging and settling of the pile, or after the pile is deposited, hardening grout is sprayed from the spout of the conduit ring and filled into the gap between the pile and the soil. A construction method for foundation piles that consists of integrating them with the soil.