JPS62141222A - Method and apparatus for bottom-expanded pile work - Google Patents

Abstract

PURPOSE:To reduce noise and vibration in a bottom-expanded pile work by a method in which a solidifying agent in a sol state is injected into a scoured hole on the lower end of a guide tube set in a hollow pile driven into the ground to expand and harden the scoured hole. CONSTITUTION:A guide tube 1 of a water-tight structure is set in the hollow P' of a hollow pile P driven into a pit drilled in the ground, and a driving body 2 with a pointed tip 22 is fitted into the tube 1 in a vertically movable manner. An aperture 4 is formed in the hollow P' with the tube 1, a buffer spring is provided between the tube 1 and the driving body 2, and a driving part 3 consisting of a weight and a wire is provided in the tube 1. A solidifying agent D in a sol state, e.g., cement mortar is injected through an injection tube 6 into scoured hole B formed on the bottom of the pile P, and the weight of the driving part 3 is dropped to lower the body 2 in order to expand the scoured hole B'. The apparatus is removed and the agent D is hardened. Noise and vibration can thus be reduced, the construction work can be speeded up, and the cost of the construction work can be curtailed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a bottom-expanding pile means for forming a bottom-expanding portion at the bottom of a hollow pile.

[Conventional technology]

Expanded pile means have the advantage of increasing the bearing capacity of hollow piles and reducing the number of piles to be erected, and are increasingly being used from the perspective of reducing construction costs.

Conventionally, as the bottom expansion pile means, for example, pedestal pile, frankie pile, simplex pile (site engineer's construction method and construction machine for foundations (published by Kindai Tosho Co., Ltd.),
The Civil Engineering Construction Data Book (published by Morikita Publishing Co., Ltd.) and the recent Civil Engineering Construction Law Encyclopedia (published by Sangyo Kenkyukai Co., Ltd.) are known, and these will be explained with reference to FIGS. 5 and 6.

Figure 5 shows the means to be carried out as a preliminary step to the erection of the hollow pile P. The vertical hole A in which the hollow pile P will be erected and the enlarged bottom hole B which will become the enlarged bottom part are prepared mechanically with a drilling machine etc. Ground E
After that, the expanded hole B is filled with concrete, etc., and the hollow pile P is erected in the vertical hole A.

Figure 6 shows the method used as a subsequent stage of construction of the hollow pile P, in which a pre-drill hole B' is dug at the bottom of the hollow pile P built in the ground E. The hole B° and the hollow part P' of the hollow pile P are filled with a filler C such as sand and pressed from above to enlarge the pre-drilled hole B' and form an enlarged bottom part.

(Problems to be Solved by the Invention) However, with the conventional technique shown in FIG. There are problems in that the fixation with the concrete filled in this is low and the strength of the expanded bottom part is low.

Further, the conventional technique shown in FIG. 6 solves the problems of the conventional technique shown in FIG. 5, but there is a problem that noise and vibration are generated when the filler C is pressed.

[Purpose of the invention]

The present invention is an improvement on the conventional technique shown in FIG. 6, and its purpose is to attenuate noise and vibration.

[Means for Solving the Problems] The present invention consists of a first invention relating to an expanding-bottom pile construction method, and a second invention relating to a bottom-expanding pile device used in one step of the first invention.

That is, the expanding bottom pile construction method of the first invention involves digging a pre-drilled hole at the bottom of the hollow pile built into the ground, and injecting a sol-like solidification material into the pre-drilled hole and applying pressure. The hole is expanded into a bulbous shape, and the solidifying material is solidified in this state to form an expanded bottom portion.

In addition, the bottom expanding pile device of the second invention includes a guide pipe with a watertight structure arranged in the hollow part of the hollow pile built in the ground, and a hollow part provided at the lower end of the guide pipe so as to be movable up and down. a pressing body that protrudes downward into a pre-drilled hole dug at the bottom of the pile;
It consists of a drive unit that moves this striking body up and down.

[Action of the invention]

The present invention achieves the following by performing the driving force shown in FIG.
It dampens noise and vibration.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

1 to 4 show a bottom expanding pile device according to the second invention in detail. Hereinafter, the first invention and the second invention will be explained in detail, focusing on the second invention.

As shown in Figures 1 to 4, the hollow pile P is built into a vertical hole that is mechanically dug. It is required to excavate B with an auger, etc.

The second invention is also based on the premise of digging the pre-drilled hole B'', and a guide pipe 1 with a watertight structure is provided in the hollow part P'' of the hollow pile P, and the lower end of the guide pipe l is shown in FIG. Sealing material 21 shown in
A pressing body 2 that ensures a watertight structure of the guide tube 1 is provided so as to be movable up and down, and a drive s3 for moving the pressing body 2 up and down is provided above the pressing body 2. The guide pipe 1 has a diameter smaller than the hollow part P'' of the hollow pile P, with a gap 4 interposed therebetween, and is arranged up to the upper end of the hollow pile P.The pressing body 2 has a sharpened part 22 at the tip. However, it is fitted into the guide tube 1 so as to be able to move up and down, and a spring 5 for buffering is provided between the guide tube 1 and the pressing body 2.

The drive unit 3 consists of a weight 31 that presses the pressing body 2, a wire 32 that pulls up the weight 31, and a wire 33 that passes through the weight 31 and pulls up the pressing body 2. It is provided.

In the second invention having such a structure, the striking force body 2 is set so as to descend and protrude into the pre-drilled hole B' when the striking force body 2 is pressed.

Therefore, in the first invention, mortar is used in the pre-drilled hole B°.

By injecting a solidified material in the form of a sol such as concrete milk and applying pressure with the pressing member 2, the pre-drilled hole B' is enlarged into a bulbous shape as shown in FIGS. 1 to 3. Then, the solidified material is solidified as it is to form the expanded bottom portion. In this first invention, the impact of the solidified material is performed at the bottom of the hollow pile P, and the material to be pressed is in the form of a sol, which causes noise.

Vibrations will be damped.

To explain the above-mentioned hammer pressure in detail with respect to the illustrated embodiment of the second invention, first, as shown in FIG. The injection is carried out using the injection pipe 6 arranged along the guide pipe 1 as shown in the figure, and the hollow pile P is
Make sure that the solidified material enters into the hollow part P'.

After this, when the weight 31 is dropped and the hammering body 2 is lowered, the solidified timber is compressed by hammering and a part of it escapes to the hollow part P' of the hollow pile P, but most of it escapes to the hole B in the pre-drilled hole B.゛ second
Expand it into a bulbous shape as shown. In this striking force, providing the sharpened portion 22 at the tip of the striking force body 2 facilitates the protrusion of the striking force body 2 into the pre-drilled hole B° filled with sol-like solidified material, and noise.

It also contributes to damping vibrations. After pressing, when the pressing body 2 is pulled up as shown in Fig. 3, the solidified material that escaped into the hollow part P' of the hollow pile P flows down and drains into the pre-excavation hole where the pressing body 2 was located. This will fill the gap B. The pre-drilled hole B' is enlarged to a predetermined size by repeating this type of pressure several times, but during this time, if necessary, solidified material may be replenished from the injection pipe 6. Then, by removing the bottom-expanding pile device from the state shown in FIG. 3 and solidifying the solidified lumber, the bottom-expanding portion will be formed. It should be noted that residual slime in the pre-drilled hole B° is a problem, but this slime moves to the side wall of the pre-drilled hole B′ by repeated application of the pressure by the pressing member 2, and is solidified by the press-in of the solidifying material. .

〔Effect of the invention〕

As described above, the expanded-bottom pile construction method according to the present invention is effective in attenuating noise and vibration because the driving force is applied at the bottom of the hollow pile and the sol-like solidified material is applied. Furthermore, since the expanded bottom part can be formed by solidifying the solidifying material after pressing,
This has the effect of speeding up construction work.

In addition to the above effects, the bottom expanding pile device according to the present invention also has the following effects:
Since the solidified material can be pressed using a simple method, construction costs can be reduced.

[Brief explanation of drawings]

Figures 1 to 3 are longitudinal sectional views showing an embodiment of the present invention, Figure 4 is a longitudinal sectional view showing an embodiment of an expanded bottom pile device, and Figures 5 and 6 are longitudinal sectional views showing a conventional example. It is a diagram. ■... Guide tube, 2... Pressing body, 3... Drive unit,
P...Hollow pile 1, P゛...Hollow part, E...Ground, B'...Pre-drilled hole. Figure 5 Figure 6

Claims (2)

[Claims] (1) A pre-drilled hole is dug at the bottom of the hollow pile built into the ground, and a sol-like solidification material is injected into the pre-drilled hole and pressed to enlarge the pre-drilled hole into a bulbous shape. , an expanded bottom pile construction method characterized by solidifying the solidifying material in this state to form an expanded bottom part. (2) A guide pipe with a watertight structure installed in the hollow part of a hollow pile built into the ground, and a guide pipe with a watertight structure installed at the lower end of this guide pipe so as to be movable up and down and dug into the bottom of the hollow pile. A bottom-expanding pile device characterized by comprising a pressing body that projects downward into a pre-drilled hole, and a drive unit that moves the pressing body up and down.