JP2002097639A - Pile burying method and jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sink and install a pile easily without using a spiral auger and reduce an amount of discharged soil accompanying the digging to prevent a steep rise in discharged soil treatment cost when the concrete pile is sunk and installed in the ground. SOLUTION: A hollow PC steel bar is used as a vertical tension member of the pile, a digging blade is attached to a lower end of the pile, compressed air and pressure water are injected through the hollow PC steel bar from the lower end of the pile, the pile is rotated to sink it into the ground, and cement milk is poured through the hollow PC steel bar after the lower end of the pile reaches a support layer to integrate a tip of the pile with the support layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method of embedding a concrete pile of about 00 mm and a jig used for the method.

[0002]

2. Description of the Related Art When laying a concrete foundation pile in the ground, it is necessary to insert a spiral auger into the hollow hole of the pile, excavate the stratum at the lower end of the pile with a spiral auger, and sink the pile while discharging soil. This is a commonly used technique.

[0003] In this case, the excavated soil in the hollow hole of the pile is discharged by a spiral auger, cement milk is supplied to the pile bottom through the hollow hole of the pile after the discharge, and the support layer and the lower end of the pile are integrated. I do. In such a method of staking a pile, it is necessary to treat all the soil excavated by the spiral auger on the ground. In recent years, disposal of such soils in civil engineering has become a problem, and the cost of disposal has been rising.

[0004]

SUMMARY OF THE INVENTION The present invention has developed a method and a jig for burying a pile which has solved the above-mentioned problems. The present invention facilitates the pile laying without using a spiral auger. An object of the present invention is to reduce the amount of earth removal caused by excavation and prevent a rise in earth removal processing costs.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a method for burying a pile, characterized by taking the following technical means. That is, the present invention uses a hollow PC steel rod as a longitudinal tension member of a prestressed concrete pile, connects a fluid supply pipe to the upper end of the hollow PC steel rod, attaches a drilling blade to the lower end of the pile, and attaches the drilling blade to the fluid supply pipe. Supply compressed air and pressure water to the hollow P
Inject from the bottom of the pile through the inside of the C steel rod, apply rotational force to the pile, sink the pile into the ground, and after the bottom of the pile reaches the support layer,
This is a method of burying piles, wherein the piles are further rotated and settled while pressure is injected with cement milk instead of compressed air and pressurized water, and integrated with the pile tip and the support layer ground.

In the present invention, a hollow PC steel rod is used as a longitudinal tension member of a prestressed concrete pile. Hollow PC steel rods were originally inserted into the hollow part by inserting another PC steel rod into the hollow PC steel rod to introduce pretension prestress at the site without using a reaction force abutment or large jack. PC that has been pre-tensioned and inserted after concrete is cast
It was developed to release the tension of steel rods and give prestress to concrete. As such a hollow PC steel rod, (outer diameter) × (inner diameter) is (19) ×
(12.6), (23) × (15.8), (29) ×
(21.8), (32) × (22), (40) × (3
0) mm and the like are commercially available. In the present invention, a hollow PC steel rod is used, and a tensile tension is applied to the hollow PC steel rod in the same manner as a normal PC steel rod to manufacture a pretensioned prestressed concrete pile. In the present invention, this hollow PC
For introducing prestressed steel bars, use ordinary PC steel bars or P
It is used in the same manner as the C steel wire, and the manufacturing process of the pile is exactly the same as the conventional one, but it is characterized in that the hollow portion is used as a fluid pipe when the pile is settled. That is, a fluid supply pipe is connected to the upper end of the hollow PC steel rod, and compressed air, pressurized water, or cement milk is supplied to the lower end of the pile through the hollow part of the hollow PC steel rod. In the present invention, a cap that applies a rotational force to the pile is attached to the head of the pile, a drilling blade is attached to the lower end of the pile, and compressed air and pressure water are supplied from the fluid supply pipe and injected from the lower end of the pile, The pile is submerged under the ground by applying rotational force. The compressed air and pressurized water soften the stratum at the lower end of the pile, and when the pile is rotated, the excavating blade agitates the stratum corresponding to the concrete thick wall portion of the pile and facilitates settlement of the pile. The sediment removed by the settlement of the pile becomes muddy and enters the hollow hole of the pile and rises. Some penetrate between the outer surface of the pile and the stratum, facilitating the settlement of the pile. Most of the removed sediment remains in the hollow part of the pile, some of which overflows from the top of the pile. In the present invention, since the spiral auger is not used in the pile settlement process, the earth removal is not actively discharged. Accordingly, the amount of earth removal is significantly reduced, and the earth disposal cost is drastically reduced.

[0007] After the lower end of the pile reaches the support layer, the pile is further rotated and settled while pressure is injected with cement milk through the hollow PC steel rod to integrate the support layer ground and the tip of the pile. At this time, the inside of the pile near the lower end of the pile is also filled with a mixture of cement milk and gravel or sand in the ground of the support layer.

The jig of the present invention, which can preferably carry out the method of the present invention, is a short cylindrical cap to be put on the upper end of a pile, and is connected to a pile head via a rotation preventing key so as to be able to apply a rotational force. A stake, which is provided with a rotational force transmitting means fixed via a spoke at the center of the upper surface, and the rotational force transmitting means is provided with an upper and lower through hole through which the fluid supply pipe is inserted at the axis. Burial jig. The jig is attached to the upper end of the pile, and the method of the present invention can be easily carried out using a pile driving device.

The above method can be applied to a case where a plurality of piles are connected and settled. In this case, a sleeve is used that communicates the upper and lower hollow PC steel bars at the connection part of the upper and lower piles. This sleeve is a hollow body that connects the upper and lower hollow PC steel rods to allow fluid to flow, and that the sleeve has the rotational force transmission strength of the upper and lower piles and also functions as a shear key. If necessary, the concrete hole at the end of the hollow PC steel rod may be enlarged. By attaching such a sleeve to the joint of the upper and lower piles, it is possible to easily realize the connection of the upper and lower piles, the rotation of the piles while supplying fluid through the hollow PC steel rod, and the sinking.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing a pile embedding process according to an embodiment of the present invention. 1. Description will be given according to FIG. 1. (a) The prestressed concrete pile 10 uses a hollow PC steel rod as a longitudinal tension member, and a drilling blade is attached to the lower end of the pile. A jig 20 is attached to the top of the pile 10, and an air pipe and a liquid supply pipe are connected to the upper end of the hollow PC steel rod. Preferably, the air pipe and the liquid supply pipe are arranged so as to alternately supply adjacent hollow PC steel rods. The pile driving device (not shown) includes a compressed air generator, a high-pressure water supply device, a cement milk supply device, and a soil discharging device.

(B) Compressed air and pressurized water are supplied from the above-mentioned supply pipe, and a rotational force is applied to the pile 10 while jetting it from the lower end of the pile 10 to sink the pile into the ground. The pressure of the compressed air is preferably 0.7 MPa (7 kgf / cm ² ) or more, and the pressure of the pressurized water is preferably 1 MPa (10 kgf / cm ² ) or more. The excavating blade 30 stirs and mixes the ground 100 by the rotation of the pile 10 and also excavates the ground at the tip of the pile to facilitate the penetration of the pile 10 into the ground. The torsional moment during pile rotation is managed so as not to exceed the resistance moment of the pile.
The excavated soil 42, 43 which has been muddy due to the interaction between the excavation blade and the jet 41 rises in the gap between the hollow portion of the pile 10 and the outer surface of the pile and the ground. Therefore, the pile can be easily settled. Therefore, no spiral auger is used. The muddy discharged soil passes through the inner surface of the hollow hole of the pile, but most of it stays in the pile, and only excess surplus is discharged from the pile head. Therefore, the amount of soil removal is significantly reduced as compared with the case where the spiral auger is inserted into the hollow portion of the pile and the entire cross section of the hollow portion of the pile is excavated to discharge all the soil discharge outside the pile. In addition, the muddy soil and compressed air that rises on the outer surface of the pile reduces friction between the pile and the stratum and facilitates settlement of the pile. When it is necessary to connect the piles in the longitudinal direction, connect the upper and lower hollow PC steel rods to the connecting parts of the upper and lower piles, and attach the sleeve having the torque transmission strength of the upper and lower piles to the PC steel rods at the connecting parts of the upper and lower piles. Attach to end and connect.

(C) Excavated soil rising through the hollow portion of the pile is mostly retained in the pile, and a part is discharged from the top of the pile as the excavated soil 44.

(D) When the lower end of the pile 10 reaches the support layer 110, supply of compressed air and pressure water is stopped, and the hollow PC is stopped.
The pile is spun down while injecting cement milk 45 as a consolidation liquid through a steel rod. The concentration of the cement milk is preferably about 60% in terms of the ratio of water cement. At this time, the cement milk 45 solidifies the support layer 46 at the lower end of the pile and also rises into the hollow portion 47 of the inside diameter of the pile to contribute to the integration of the support layer ground and the pile.

(E) A hardened cement milk 48 is formed in which the support layer ground and the tip of the pile are integrated. Jig at the top of pile 2
0 is removed and pile construction is completed.

Next, a jig used in the present invention will be described. 2 is a plan view of an embodiment of the jig of the present invention, FIG. 3 is a side view thereof, FIG. 4 is a side sectional view thereof, FIG. 5 is a partially enlarged sectional view thereof, and FIG. FIG. This jig 20
Consists of a short cylinder 21 placed on the upper end of the pile 10 and has a cap shape. A rotation preventing key 25 is attached to the head of the pile 10 by welding or the like. In this example, four rotation prevention keys are shown, but this number is not limited. The side wall of the short cylinder 21 is provided with a notch 26 which is opened downward and the inner part is bent in a hook shape horizontally, and the short cylinder 21 is lowered downward from above so that the rotation preventing key 25 enters the notch 26, When the short cylinder is slightly rotated, the rotation prevention key 25
Are to be locked. Jig 2
0 and the pile 10 rotate integrally with the rotation direction of the pile 10. When the jig 20 is reversed, the locking is released, and the jig 20 can be pulled up from the pile head and removed. The top of the jig 20 is open, and a number of spokes 22 are attached thereto, and a boss 23 at the center thereof is provided with a torque transmitting means 24 for coupling with a pile rotating device. The rotating force transmitting means 24 is provided with a rotating force from the pile rotating device, and rotates the pile 10 via the jig 20.

As shown in FIG. 4, the torque transmitting means 24
Have upper and lower through holes, through which the fluid supply pipe 27 passes vertically. The fluid supply pipe 27 is a double pipe. In this example, the outside is a passage for compressed air, and the inside is a passage for pressurized water or cement milk. The fluid supply pipe 27 is connected to a supply side pipe (not shown) via a swivel joint. And the fluid supply pipe 27
The downstream side is connected to a compressed air supply pipe 28 and a liquid supply pipe 29, respectively, as shown in FIG. 6, and the compressed air pipe 28 and the liquid supply pipe 29 are embedded in the concrete 11 of the pile 10. And connected to the hollow PC steel rod 12. FIG. 5 is an example showing the details of this connecting portion.
An end plate 13 is attached to a sleeve 14 fitted in the head of a hollow PC steel material 12 embedded in concrete 11 of a pile.
And is removably inserted through the hole of. In the sleeve 14, a seal portion provided with a packing is provided.

FIGS. 7 to 11 show examples of the structure of the lower end of the pile. FIG. 7 is a bottom view of the end plate 15 at the lower end surface of the pile 10, and shows a hollow PC steel rod 12a for supplying compressed air and a hollow P for supplying liquid.
This shows that the C steel bars 12b are alternately arranged. FIG. 8 shows the end plate 15 to which a short piece 31 of angle iron is attached as a cutting blade, and FIG. 9 is an elevation view thereof. The end plate 15 is provided with a reinforcing band 16, and the short piece 31 of angle iron is arranged so as to excavate the ground below the bottom of the pile when the pile 10 rotates, and to collect excavated earth and sand in the center of the pile. FIGS. 10 and 11 show an example in which excavating blades made of the bar-shaped metal piece 32 are attached, and the rest is the same as FIGS. 8 and 9.

FIGS. 12 and 13 are a side view and a front view showing the pile driving device 50. FIG. The pile driving device 50 is provided with a mast 51 at the front end of the main body 54, which is held in an upright position by a stay 53, and the pile 10 is suspended by a rotating device 52 that moves up and down along the mast 51 via a sheave 55. Into the ground. The connection between the rotating device 52 and the pile 10 is performed using the jig 20 according to the present invention. This jig 20 has a hollow P
A fluid supply pipe connected to the center hole of the C steel rod;
And a line 56 for sending a fluid from a compressed air generator, a pressure water generator, and a cement milk producing apparatus mounted on the jig 20 to a supply pipe of the jig 20.

[0019]

Since the method and jig for burying a pile according to the present invention are configured as described above, it is not necessary to use a spiral auger, and the amount of excavated soil can be significantly reduced. In addition, since the ground is directly excavated by the excavation blade at the tip of the pile, the ground is not loosened, and the support layer ground is integrally fixed by the injected cement milk, thereby generating a stable supporting force. In addition, a gap is easily generated between the outer peripheral surface of the pile and the ground due to the pressure water injection and the rotation of the pile, and the settlement resistance of the pile is reduced. This gap has an excellent effect that when cement milk is injected, cement milk infiltrates, increases the frictional force on the peripheral surface of the pile, and greatly contributes to the supporting force of the pile.

[Brief description of the drawings]

FIG. 1 is a process diagram showing a burial process of a pile according to an embodiment.

FIG. 2 is a plan view of the embodiment of the jig.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a side sectional view of FIG. 2;

FIG. 5 is a partially enlarged sectional view of FIG. 4;

FIG. 6 is a view on arrow AA of FIG. 3;

FIG. 7 is a bottom view showing an example of the structure of the lower end of the pile.

FIG. 8 is a bottom view showing an example of the structure of the lower end of the pile.

FIG. 9 is an elevation view showing an example of the structure of the lower end of the pile.

FIG. 10 is a bottom view showing an example of the structure of the lower end of the pile.

FIG. 11 is a side view of FIG. 10;

FIG. 12 is a side view showing the pile driving device.

FIG. 13 is a front view showing the pile driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Prestressed concrete pile 11 Concrete 12 (12a, 12b) Hollow PC steel rod 13 End plate 14 Sleeve 15 End plate 16 Reinforcement band 20 Jig 21 Short cylinder 22 Spoke 23 Boss 24 Rotary force transmission means 25 Rotation prevention key 26 Notch 27 Fluid Supply pipe 28 Compressed air supply pipe 29 Liquid supply pipe 30 Drilling blade 31 Short piece of angle iron 32 Bar-shaped metal 41 Injection 42, 43 Drilled soil 44 Drainage 45 Cement milk 46 Support layer 47 Hollow part 48 Cement milk hardened body 50 Pile driving device Reference Signs List 51 mast 52 rotating device 53 retainer 54 main body 55 sheave 56 line 100 ground 110 support layer

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Claims (2)

[Claims] 1. A hollow PC steel rod is used as a longitudinal tension member of a prestressed concrete pile, a fluid supply pipe is connected to an upper end of the hollow PC steel rod, and a drilling blade is attached to a lower end of the pile, and compressed to the fluid supply pipe. Air and pressure water are supplied and injected from the lower end of the pile through the hollow PC steel rod, and a rotational force is applied to the pile to sink the pile into the ground. And a method of burying a pile, wherein the pile is further rotated and settled while pressure is injected with cement milk instead of the pressurized water, and integrated with the pile tip and the support layer ground. 2. A short cylindrical cap to be put on an upper end of a pile, comprising: a coupling portion which is coupled to a pile head and a rotation preventing key so as to be capable of imparting a rotational force, and is fixed to a central portion of the upper surface via a spoke. A jig for burying a pile, comprising a force transmitting means, wherein the rotating force transmitting means has an upper and lower through hole through which a fluid supply pipe is inserted in an axis.