JPH05132934A - Execution method of pile - Google Patents

Abstract

PURPOSE:To decrease the amount of removed earth, to make it possible to decrease the amount of water used even in the case water is included in the removed earth, to enable the removed earth to decrease water content, to make it possible to settle a pile smoothly and to prevent the influence on bearing force of the pile caused by the boiling of ground water because stirred earth is left remaining in the hollow pile. CONSTITUTION:A stirring auger provided with an excavation wing 4 and an air injection hole 5 on the front end of the main column 2 having stirring members radially at intervals lengthwise is entered into the ground while turning it to inject pressure air through the air injection hole 5, and a stirring hole 6 filled with stirred earth having required length and the approximately same inside diameter as that of a pile is formed. An intermediate excavation auger is inserted into a hollow pile having both opened ends to insert the hollow pile into the stirred hole formed in the previous process, and the hollow pile is settled up to required depth while rotating the hollow pile and the intermediate excavation auger in opposite directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing ready-made piles buried in the ground.

[0002]

2. Description of the Related Art Off-the-shelf piles in a vibration-free and noise-free state
As a method of submerging into the ground, pre-boring a hole for inserting a pile and then submerging the pile into the hole, inserting a spiral auger into the hollow part of the pile and discharging the soil at the tip of the pile to the ground. Medium excavation method to stake piles, jet method to muddy the tip of hollow piles with jet water to sink the piles, and other methods to sink the piles into the ground, and expand the bulb by cement milk injection at the support layer at the bottom of the piles. The method of constructing a pile is generally used to obtain a high bearing capacity for the structure formed on the pile.

Among these, in the pre-boring method, in order to maintain the hole wall of the excavation hole, the soil inside the pile is made into a mud with a large amount of water, and the excavation hole is filled or filled with a bentonite solution. Since it balances the soil pressure and the groundwater pressure to prevent the collapse of the hole wall, there is a problem that a large amount of muddy water is discharged after the pile is laid down and the residual soil with a high water content must be treated. A large amount of muddy water is also discharged by the jet method. In addition, in the medium excavation method and the like, most of the soil in the hollow portion of the pile is discharged, so a large amount of residual soil is generated. In addition, if high-pressure groundwater spouts (boiling) during the excavation in the hollow part of the pile that is this space, the surrounding soil will be agitated and an unfavorable cavity will be created around the pile, and the pile will be laid down to the support layer. After that, if the hollow part of the pile is not backfilled or not fully filled with water, groundwater pressure may cause water to enter the hollow part from the bottom of the pile (boiling) and weaken the bearing capacity of the support layer near the bottom of the pile. However, there is a problem that the sedimentation speed is greatly affected by the hardness of the intermediate layer and the friction between the pile outer periphery and the stratum is cut, but the stratum and construction make the sedimentation unsatisfactory.

[0004]

DISCLOSURE OF THE INVENTION The present invention has a small amount of soil discharged, and even when the soil is soaked with water, the amount of water used can be reduced, the amount of soil discharged can be made low, and the work site is not polluted with water. (EN) It is possible to provide a method of constructing a pile which can be smoothly sunk and the agitated earth and sand remain inside the hollow pile so that the bearing capacity of the pile due to boiling of groundwater can be avoided.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an agitator having an excavation blade and an air ejection hole at the tip of a main column radially provided with an agitator at intervals in the longitudinal direction. Rotating the auger while injecting pressurized air from the air ejection hole into the ground to form a stirring hole of a required length filled with stirred soil having an inner diameter almost equal to the pile diameter, and both ends Inserting a hollow digging auger into the open hollow pile and inserting it into the stirring hole formed in the above step, and submerging the hollow pile to the required depth while rotating the hollow pile and the hollow digging auger in opposite directions. It is in the method of constructing a pile with and.

[0006]

[Operation] First, the ground is loosened with high-pressure air, and hollow piles are inserted into the stirring holes filled with stirred soil, and the piles are sunk by the underground excavation method. Even a small amount does not pollute the site and the processing cost is low. Also, when the pile is sunk by the medium excavation method, the pile and the medium excavation auger are carried out while reversing each other, so that the friction between the hole wall and the pile peripheral surface can always be reduced, and the load of the medium excavation auger can be reduced.
The pile can be smoothly sunk and the height of the pile can be prevented. Since the agitated soil is always filled in the hollow part of the sunk pile, the problem of boiling can be solved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for implementing a pile construction method according to the present invention will be described with reference to FIGS. As shown in FIG. 1, an agitating auger 1 having an excavation blade 4 and an air ejection hole 5 at the tip of a main column 2 radially mounted with an agitating material 3 at intervals in the longitudinal direction is used. From which air of about 7 kg / cm ² or less is spouted and rotated to penetrate into the ground, the inner diameter of which is substantially equal to the outer diameter of the hollow pile 7 at the sinking depth of the hollow pile 7,
The stirring hole 6 filled with the stirred soil is formed.

At the trace of the stirring auger 1 taken out from the stirring hole 6, as shown in FIG. 2, a hollow pile 7 having both ends opened is erected, and a hollow digging auger 8 is inserted into the hollow pile 7. The connector 12 having the earth discharging hole 13 on the side surface is connected to the end plate 11. The pile rotating device 10 is connected onto the connector 12. The medium dug auger 8 is a connector 12 and a pile rotating device
It is connected to the hollow excavator auger rotating device 9 arranged on the upper part of the pile rotating device 10. The pile rotating device 10 and the hollow excavator auger rotating device 9 are fixed to a not-shown sledge arranged on the ground.

The hollow pile 7 is rotated while being held by the pile rotating device 10, and the hollow dug auger 8 is rotated reversely to the hollow pile 7 by the hollow dug auger rotating device 9 while loosening the soil at the lower end of the hollow pile 7. The hollow pile 7 is submerged. Since the hollow pile 7 is rotated in the opposite direction to the hollow dug auger 8, the friction with the soil inside is reduced, and by rotating itself, the friction with the soil around the outer periphery is also reduced and the settlement is easily performed. At this time, excess earth and sand accompanying the sinking of the hollow pile 7 is discharged to the ground through the earth discharging hole 13 provided on the side surface of the coupler 12. A steady rest 16 is attached to the shaft portion of the hollow dug auger so that the inner surface of the hollow pile 7 is not scratched. Medium dug auger 8 for joint piles
The auger shaft and the hollow stake 7 are connected to each other and similarly sunk.

In this way, when the hollow pile 7 is sunk and the lower end of the hollow pile 7 reaches the vicinity of the support layer, the expansion head 14 at the tip of the auger shaft is expanded in the same manner as in the conventional case, and the hollow pile 7 is closed. The earth and sand are stirred to an outer diameter larger than the outer diameter of
Cement milk is injected and stirred from the tip of the auger shaft to form the enlarged bulb 15 and the hollow pile 7 is rotationally fixed. Then, the enlarging head 14 is contracted and rotated to complete the pulling operation of the hollow dug auger 8.

[0011]

According to the method of constructing a pile according to the present invention, the amount of water discharged is small, the amount of water used can be reduced even when the discharged water is soaked, and the discharged water can be made low in water. Without getting dirty
Since piles can be smoothly sunk and agitated soil remains inside the hollow piles, it is possible to avoid affecting the bearing capacity of the piles due to boiling of groundwater.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a process of forming a stirring hole of a required length filled with stirred soil having an inner diameter substantially equal to a pile diameter according to the present invention.

FIG. 2 is an explanatory view of a step of sinking a hollow pile into a stirring hole in which the hollow pile is formed in advance according to the present invention.

FIG. 3 is an explanatory view of a process of forming an enlarged bulb on the lower end of the hollow hollow pile in the same manner as the conventional method and fixing the lower end of the hollow pile to the support layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Agitation auger 2 Main column 3 Agitation material 4 Excavation blade 5 Air jet hole 6 Agitation hole 7 Hollow pile 8 Medium excavation auger 9 Medium excavation auger rotation device 10 Pile rotation device 11 End plate 12 Coupling device 13 Excavation hole 14 Expansion head 15 Enlarged bulb 16 steady rest

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadao Hattori 1-8-3 Shimbashi, Minato-ku, Tokyo Inside Nippon Concrete Industry Co., Ltd.

Claims (1)

[Claims] 1. A stirring auger having an excavation blade and an air ejection hole at the tip of a main column radially provided with an agitation material at intervals in the longitudinal direction, and ejecting pressurized air from the air ejection hole while rotating. While intruding into the ground, forming a stirring hole of a required length filled with stirred soil having an inner diameter almost equal to the pile diameter, and inserting a hollow dug auger into the hollow pile with both ends open A method of constructing a pile, comprising the step of inserting the hollow pile and the hollow dug auger into the stirring hole formed in the step while rotating the hollow pile and the hollow auger in opposite directions to sink the hollow pile to a required depth.