JPS59130919A - Removal of existing hollow pile - Google Patents

Abstract

PURPOSE:To easily remove out existing hollow piles by a method in which the upper end opening of an existing hollow pile is closed by connecting an enclosed auxiliary pipe, etc., having a liquid charging port, and bentonite mortar, etc., is injected through the charging port and pressed. CONSTITUTION:An auxiliary enclosed pipe 4 is welded to the upper end opening of an existing hollow pile 2. Water 12 is injected into the space 10 through a hose 11 connected to a charging port 8 and a pressure is applied, whereupon the water flows down through soil and sand 9 in the pile 2 and along the inner surface of the pile 2 to reduce the bonding force between the pile 2 and the ground 1. A bentonite liquid 13 is injected into the space 10 and pressed, and then bentonite mortar 14 is injected and a pressure is applied. Furthermore, pressure water 18 is injected into the space 10 and a pressure is applied to transmit the pressure to the ground surface inside the pile 2 to generate a pushing-up force in the pile 2, and the pile 2 is slowly pulled up by means of a crane, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing existing hollow piles such as unused bridge piers and pill foundation piles.

Conventionally, in order to pull out such an existing hollow pile, the upper end of the pile is gripped by a suitable gripping device and then the gripping device is moved upward to pull it up. A method has been adopted in which a steel pipe is driven into the outer circumference of the hollow pile so that it fits into the hollow pile, and then the hollow pile is pulled out along with my.However, in many cases, a vibrating pile driver is used to pull out the pile, so it takes a long time. Not only does this generate a lot of noise, but it can also have an adverse effect on the surrounding ground and buildings, and it also has drawbacks such as requiring large machinery and a long time to pull it out.

In order to eliminate such drawbacks, the present invention has been developed by sealing the upper end opening of an existing hollow pile by connecting a sealing auxiliary pipe or the like having a liquid inlet, and then injecting water into the upper end of the existing hollow pile through the inlet. The present invention provides a method for removing an existing hollow pile, which is characterized by generating uplift pressure on the existing hollow pile by injecting and pressurizing a liquid such as Ito7rutal, and then pulling it out using an appropriate pulling device. be.

The embodiments of the present invention will be explained with reference to the drawings.
As shown in the figure, an existing hollow steel pipe pile (2) is buried in the ground (1) and has an opening (2a) at the bottom end, with an opening at the top end (3) protruding from the ground surface. Then, weld the open lower end of the steel auxiliary sealed pipe (4) of the same diameter as the existing forked pile (2) to integrate it (Figure 2).

As shown in Fig. 7, this auxiliary sealed tube (4) has a steel top plate (5) welded to its upper end opening to seal the opening. A locking hole (6) is bored in the pipe (7) and an injection port (8) communicating with the inside of the pipe is provided on the outer periphery of the pipe.

Before attaching this auxiliary sealed pipe (4) to the existing pile (2), excavate and remove the earth and sand (9) at the top of the existing pile (2) using an auger screw, etc. The pulling resistance of the pile (2) is weakened.

Next, 'water 02) is injected into the space 00 formed by the sealed pipe (4) and the surface of the earth and sand (9) in the existing pile (2) through the hose (11) connected to the injection port (8). When the water is filled and pressurized, the pressurized water enters and flows down through the earth and sand (9) in the existing pile (2) and the inner peripheral surface of the pile (2), and flows down to the lower end of the opening of the pile (2). After reaching this point, it dissipates into the ground and rises toward the ground surface along the outer circumferential surface of the pile (2).

In this way, pressurized water enters and flows into the ground, creating water channels on the inner and outer peripheral surfaces of the existing pile (2), thereby reducing the adhesion force between the existing pile (2) and the ground (1).

Next, replace the pressurized water with a hose (1υ) to the inlet (8).
Inject Space 0 (Besitoite liquid 03 into the space) and pressurize it. As a result of this injection, the besitonite liquid 03) flows along the aforementioned water path and forms a layer of besitonite liquid between the inner and outer circumferential surfaces of the existing pile (2) and the soil, and this layer It plays the role of reducing the frictional resistance that occurs between the soil and sand when it is pulled out (Figure 3).

After that, replace the Besitoite aqueous solution with the hose ()
1) Besitonite mortar 0 from the injection port (8) through
When 4) is injected, the upper end of the water channel described above is blocked by this besito mortar θ→.

After filling the space with the mortar 049, pressurized water (b) is injected from the injection port (8) and pressurized, and the pressure is applied to the top plate (5) of the sealed tube (4).
and existing piles (2) via besitonite rutal 04)
The force is transmitted to the ground surface inside the ground, and the ground surface acts as a reaction force to generate an uplift force on the existing pile (2), pushing the pile (2) upward and gradually starting to pull it out. Pressurized water θB) is replenished and press-fitted according to the amount of this withdrawal.

Furthermore, in order to quickly pull out the existing pile (2),
Connect the base material Wire (15) to the locking hole (6) of the Cha・ν+Jig plate (7) installed upright on the top plate (5) of the sealed tube (4), and then remove this Wire P (15). -shihook (16)
) and pull out the existing pile (2) by an appropriate length.

This pulling out creates a cavity (17) at the lower end of the existing pile (2).
), but this cavity axis) is filled by the lateral movement of earth and sand, and in some cases, the above-mentioned beshito mortar 0→
is filled by flowing in with pressurized water 08), and the beshito mortar 0→ filled in the cavity (17) further penetrates into the ground to solidify the looseness of the ground.
Improve the ground. ,.

If it is difficult to pull out the existing pile (2), attach a vibrating pile driver (not shown) to the mechanical strength plate (7) of the sealed pipe (4) and pull out the existing pile (2). Sometimes it is moved upward while applying vibrations.

In this way, when the existing pile (2) is pulled out for a certain length, a hole () is drilled in a part of the pile near the ground surface to drain the water in the space 00, and then the hole (19) is The auxiliary pipe (4) having the above-mentioned structure is welded again to the upper end surface of the existing pile that remains, and the steps after injecting water are repeated in the same manner as described above, and the entire existing pile is pulled out.

In addition, in the above example, a method for removing an existing pile made of steel pipe was described, but if the pile is open at the lower end and an auxiliary sealed pipe can be attached to the upper end in a watertight manner, a cosiclete pile can be used. Even if there is, the method of the present invention can be adopted. Furthermore, before injecting besitonite t rutal θ→, water and besitonite aqueous solution were sequentially injected into the upper end space of the pile. Wf-
This is done to reduce friction resistance, and depending on the condition of the ground and the level of pull-out resistance, only Beshitosu I-e Rutar may be injected into the space at the top of the pile to fill it, and then pressurized. It is also possible to generate uplift force on the pile.

Also, instead of injecting water and besitoite aqueous solution, in advance,
It is also possible to remove soil and sand from around the pile using an autojet.

As described above, in the present invention, when pulling out an existing hollow pile that is driven into the ground and has an open lower end, the upper end opening of the existing hollow pile is first sealed, and the inside of the upper end of the existing hollow pile is sealed. A liquid such as besithonite mortar is injected into the pile and pressurized, and the applied force uses the ground surface inside the existing hollow pile as a reaction force to generate uplift force on the existing hollow pile.In this state, the existing hollow pile is Since this method is related to a method for removing existing hollow piles that is characterized by being pulled up, it is possible to reduce the frictional resistance between the antibody and the ground by injecting Besitoite, etc. It can be easily pulled out, and at the same time as the pile is pulled out, it is possible to fill the voids created in the pile with mortar, etc., and also infiltrate the ground around the voids, which prevents ground changes. Not only does it not have any negative effects such as, but also allows ground improvement to be carried out at the same time, and it does not require post-processing work such as backfilling, thereby improving work efficiency.

In addition, there is no need to use a vibrator when pulling out piles, and even if one is used, it can be a small and auxiliary device, so there will be no adverse effects such as vibration pollution on the surrounding area.

Furthermore, the removal work can be carried out without the need for large machinery, and by branching off a liquid injection hose such as Beshito Mortar and injecting it under pressure at once, it is possible to pull out multiple existing hollow piles at the same time. - It has the features of being extremely efficient.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 to 3 are simplified sectional views showing the working steps thereof, and FIG. 7 is a perspective view of a sealed tube. (1)...Ground, (2)...Existing piles, (4)...
Sealed tube, (8)... Inlet, 0 (g... Space, (12)
) (18)... Pressurized water, (13)... Beshitonite liquid, (+4):... Beshitonite mortar, (](+
1... Qureshi's hook 0

Claims (1)

[Claims] ■ When pulling out an existing hollow pile that is driven into the ground and has an open lower end, first, the upper end opening of this existing hollow pile is sealed, and then the existing hollow pile is removed. A liquid such as beshito mortar is introduced into the upper end of the hollow pile and pressurized, and the applied force generates an uplift force on the existing hollow pile by using the ground surface inside the existing hollow pile as a reaction force. A method for removing existing hollow piles, which is characterized by pulling up the existing hollow piles using methods such as lifting the existing hollow piles.