JP2691698B2 - Foundation pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation pile for fixing a large structure such as a power transmission tower or a radio relay tower to the ground,
The present invention relates to a foundation pile that can strongly resist both tensile force and compressive force applied from a structure.

[0002]

2. Description of the Related Art As a foundation for fixing large structures such as power transmission towers and radio relay towers to the ground, a pile foundation is used because a downward compressive force and an upward tensile force are simultaneously applied from the structure. Often used. The pile foundation consisted of a concrete foundation part that served as a pedestal at the top and a foundation pile that digs deep into the ground at the bottom. Conventionally, pile foundations using steel pipe piles have been used for power transmission towers, but the compressive force from the structure is supported by supporting the bottom of the foundation pile on the ground, and the tensile force of the concrete foundation is used. In the state of resisting by its own weight, most of the compressive force was the foundation pile, and the tensile force was that of the concrete foundation, which individually corresponded to the resistance. For this reason, both the foundation pile and the concrete foundation must be made large enough to satisfy both the design load of compression and tension. And the cost was high.

[0003]

The problem to be solved by the present invention is to solve the above-mentioned problems and to have a high resistance force in correspondence with both compressive force and tensile force, which is safe and reliable. The purpose of the present invention is to provide a foundation pile which is high in cost and can be made small in size and economical.

[0004]

[Means for Solving the Problems] The structure of the present invention which has solved the above problems is as follows: 1) An annular woven bag is provided on the outer peripheral surface of the effective adhesion length part of the hollow pile used for the pile foundation of a large structure to the ground. multiple attachment at predetermined intervals, provided with a hole for grouting leading to each woven in a cloth bag from the pile inside, mounted a check valve that allows flow only into the cloth bag in woven into the hole from the pile inside, from the pile inside
Multiple holes for grout injection on the outer peripheral surface of the part without the woven bag
In addition to being installed, only the inflow from the inside to the outside of the pile is allowed in this hole.
Foundation pile characterized by mounting a non- return valve to accommodate 2) Spiral long woven fabric bag on the outer peripheral surface of the effective attachment length of hollow pile used for pile foundation of large structure to the ground A foundation characterized in that it is wound around and installed with a plurality of holes for grout injection that lead from the inside of the pile to the inside of the woven bag, and a check valve that allows only inflow from the inside of the pile into the inside of the woven bag. Pile 3) Grout from the inside of the pile to the outer surface of the part without the woven bag
A plurality of holes for injection are provided, and the holes are inserted from the inside to the outside of the pile.
The check valve that allows only the inflow to the side is attached to the above 2)
The foundation pile described above 4) Put the woven fabric bag up in the compacted state.
Hold the bag lightly from below and inflate the woven bag toward the outer circumference of the pile.
The pair of upper and lower bag holding frames does not interfere with the
The above 1) provided on the upper side and the lower side of the attached part respectively.
Compact to the state on whether the upper and lower were folded the foundation piles 5) woven cloth bag
And hold it lightly, and the expansion of the woven bag toward the outer circumference of the pile
A pair of upper and lower bag holding frames that do not interfere
2) or 3) provided on the upper side and the lower side of the minute, respectively.
It is in the foundation pile described in .

[0005]

[Operation] The foundation pile of the present invention is used for the foundation installation ground such as a steel tower.
It is hung from the top and inserted into the hole for foundation pile construction that was previously excavated with a boring machine. While holding the foundation pile in the correct posture with respect to the ground, a grout press-fitting device is connected to the hollow part opening in the upper part of the pile body to press the grout into the foundation pile. The press-fitted grout enters the woven cloth bag on the outer circumference from the hollow portion through the hole with the check valve on the pile body, and expands the woven cloth bag in the outer circumferential direction of the foundation pile. The woven bag expands in the gap between the pile body and the ground, and the surface adheres to the ground. If the grout press-in is continued as it is, the internal pressure of the woven cloth bag will increase, and prestress will occur between the pile body and the ground with the woven cloth bag sandwiched between them, and the grout in the woven cloth bag will be dehydrated by the pressurization, and the hardened component will be contained. Excess water is squeezed out of the woven bag and penetrates into the surrounding ground. At this time, since the woven cloth bag has a tight weave, cement particles do not flow out. When the pressure inside the woven bag reaches a predetermined amount and the prestress to the pile body and the ground becomes sufficient, stop the grout press-fitting and remove the press-fitting device. The pressure inside the bag filled with grout is maintained by the check valve attached to the hole of the pile body, and the grout hardens as it is in the state where the woven cloth bag adheres to the ground and is prestressed. The surrounding ground is also hardened to some extent by the excess moisture containing the hardening component from the permeated woven cloth bag, and adheres integrally with the woven cloth bag. The grout and woven bag, which have significantly increased strength after hardening due to pressure dehydration, act as tensile reinforcements for the pile body while prestressing the ground, and when tensile force is applied to this foundation pile, It significantly increases the shear pull-out resistance to and allows it to resist tensile forces.

In the structure in which a hole for grouting is provided in a portion of the pile body where there is no woven bag, when the grout is pressed into the inside of the foundation pile, the grout passes through each hole from the hollow portion to the inside of the woven bag. And it flows into the gap between the pile body and the ground. The woven bag expands and adheres to the ground, prestressing the pile body and the ground. On the other hand, the grout that has entered the gap between the pile body and the ground completely fills the gap and penetrates from the surface of the ground to the inside. When the pressure inside the woven bag reaches the specified amount and the prestress to the pile body and ground becomes sufficient, stop the grout press-fitting and remove the press-fitting device.
The check valve in each hole prevents the press-fitted grout from flowing back into the hollow portion. The gap between the pile body and the ground is completely filled with the woven bag and the grout, so there is no relief of pressure from the part of the woven bag that is not in contact with the ground, and after hardening, the woven bag is more strongly pretended by the ground. In addition to applying stress, the grout between each woven bag hardens directly in the state of being integrated with the ground, acts as a protrusion protruding from the ground to the pile side, and each woven bag strongly joined to the pile body By engaging with this, it is possible to strongly resist the upward pulling force.

In the structure in which a pair of upper and lower bag holding frames for woven bags are attached to the outer periphery of the pile body, when the foundation pile is inserted into the building hole, the woven bag is folded and held by the upper and lower bag holding frames. Let
Prevent the woven bag from hanging and obstructing insertion. When the grout is pressed in after the foundation pile is inserted, the pressure inside the woven fabric bag increases and expands and spreads in the outer peripheral direction. Along with this, the woven bag gradually comes off from the bag holding frame and comes out of the holding state. The woven bag is inflated, and the surface finally comes into close contact with the ground to give a prestress. The bag holding frame after the woven bag is removed does not affect the woven bag and does not hinder the expansion.

In the construction in which the grout injection pipe connected to each hole of the pile body is provided, the grout press-fitting device is connected to the pipe opening to press the grout. The grout passes through the pipe and reaches the outer periphery of the pile body from the hole with check valve. It is possible to separately fill the hollow part of the pile body outside the pipe with grout or concrete, or to leave it in the hollow state.In the latter case, the total amount of grout can be reduced and injection can be done in a short time. It

[0009]

An embodiment of the present invention will be described with reference to the drawings.
This example is an example in which woven bags are attached at predetermined intervals, grout injection holes leading to a portion without a woven bag are also provided, a pipe is connected to each grout injection hole, and a pair of upper and lower bag holding frames are attached. is there. FIG. 1 is an explanatory view showing a pile erection work of an embodiment, FIG. 2 is an explanatory view showing a grout press-fitting state of the embodiment, FIG. 3 is an explanatory view showing a grout injection hole of the embodiment, and FIG. 5 is an explanatory view showing a cross section of a pile, FIG. 5 is an explanatory view showing a woven cloth bag holding state of the embodiment, FIG. 6 is an explanatory view showing a usage state of the embodiment, and FIG. 7 is an explanation showing another example of the woven cloth bag of the embodiment. It is a figure.

The foundation pile 1 of this embodiment uses a steel pipe pile 2 having a diameter of 400 mm and a length of about 30 m as a pile body. On the outer circumference of the steel pipe pile 2, an annular woven cloth bag 5 made of aramid fiber having a width of about 1 m in the vertical direction when expanded and a width of 50 mm or more in the circumferential direction is attached at a pitch of 1 m. The upper and lower edges of the woven cloth bag 5 and the steel pipe pile 2 are water-tightly joined with an adhesive having high tensile strength. Further, a cross section in which the ends of the woven fabric bag 5 which are folded and compact are put on the outer periphery of the steel pipe pile 2 above the upper edge of the woven fabric bag 5 and below the lower edge to prevent the woven fabric bag 5 from hanging down. An L-shaped annular bag holding frame 6 is provided. The steel pipe pile 2 is provided with holes 2a communicating from the hollow portion 2b to the outside at equal pitches so as to be located at the center of the portion having the woven cloth bag 5 and the portion not having the woven fabric bag 5, respectively. Pipes 3 for injecting the grout 7 extending from above the pile 2 are branched and connected. In addition to this, each hole 2a is provided with a check valve 4 which allows the grout from the pipe 3 to the outer peripheral direction and completely stops the reverse flow.

As another example of the woven cloth bag 5 of the present embodiment, an example of the woven cloth bag 5 attached in a spiral shape so as to surround the outer circumference of the steel pipe pile 2 is shown (see FIG. 5). In this case, the bag holding frame 6 is also provided spirally above and below the woven cloth bag 5.

The foundation pile 1 of this embodiment is used as a pile foundation 9 of a steel tower 10.
In the case of using it, first, the building hole 8a of the foundation pile 1 is excavated at a predetermined position of the ground 8 on which the pile foundation 9 is installed by a boring machine or the like. The foundation pile 1 is placed in the building hole 8a that has been excavated.
Is hung from the top by the self-propelled crane 11 and inserted. At this time, since the woven fabric bag 5 of the foundation pile 1 is held from above and below by the bag holding frame 6 and does not hang down or spread laterally, it does not hinder the insertion of the foundation pile 1 and is easy to insert. After the insertion, the foundation pile 1 is held at the center position of the building hole 8a, and the grout 7 is inserted into the pipe 3 for injecting the grout 7 protruding from the opening of the hollow portion 2b in the upper portion of the steel pipe pile 2 which is the pile body. 12 is connected, and the grout 7 is press-fitted from the press-fitting device 12. The press-fitted grout 7 passes through the pipe 3 and the steel pipe pile 2
The check valve 4 of the hole 2a is pushed open and flows into the gap between the steel pipe pile 2 and the ground 8 in each woven bag 5 and in the portion where the woven bag 5 is not present. The woven cloth bag 5 expands in the outer peripheral direction of the foundation pile 1 by press-fitting the grout 7, and the portion held by the bag holding frame 6 comes off the bag holding frame 6 by the force of expanding in the outer peripheral direction with the expansion, The entire woven cloth bag 5 is released from the holding state. Then, the woven cloth bag 5 continues to expand between the steel pipe pile 2 and the ground 8, and the surface thereof comes into close contact with the ground 8. If you continue to press grout 7 as it is,
The internal pressure of the woven cloth bag 5 increases, pre-stress is generated in the direction from the inside of the woven cloth bag 5 to the steel pipe pile 2 and the ground 8, and
The grout 7 in the woven cloth bag 5 in the pressurized state is dehydrated, and excess water containing a hardening component such as cement milk is squeezed out of the woven cloth bag 5, and a part of it is adhered to the surrounding ground 8 Penetrate into. At this time, since the texture of the woven cloth bag 5 is dense, the cement particles do not flow out from the woven cloth bag 5. On the other hand, the steel pipe pile 2 and the ground 8 where there is no woven bag 5
The grout 7 that has flowed out into the gap between and completely fills the gap portion as in the woven bag 5, and a part of the grout 7 penetrates into the ground 8 through the cracks and voids on the surface of the ground 8. When the pressure in the woven bag 5 reaches a predetermined amount and the prestress to the steel pipe pile 2 and the ground 8 becomes sufficient, the press-fitting device 12 stops the press-fitting of the grout 7, and the press-fitting device 12 and the pipe 3 are connected. Remove. The pressure in the woven bag 5 filled with the grout 7 is retained by the check valve 4 in the hole 2 a of the steel pipe pile 2. There is no backflow of the grout 7 to the pipe 3 from the part other than the woven bag 5 by the function of the check valve 4. The grout 7 is thus cured while the woven bag 5 is in close contact with the ground 8 and is prestressed.
Since the grout 7 in the woven bag 5 has been dehydrated under pressure,
The strength after curing is significantly higher than that of the grout 7 in other portions. The surrounding ground 8 is also hardened to some extent by the permeated excess water, and is brought into close contact with the woven bag 5 integrally.

When the required number of foundation piles 1 have been placed in the same manner as above, a concrete foundation 9a connected to the foundation piles 1 is placed above the foundation piles 1. The concrete foundation 9a and the foundation pile 1 serve as a pile foundation 9 that supports the steel tower 10. In the foundation pile 1, the grout 7 in the woven cloth bag 5 strongly prestresses the ground 8, and the grout 7 is integrated with the ground 8 even in a portion other than the woven cloth bag 5 to form the ground 8
It functions as a protrusion from the tongue and is in a state of being meshed with each woven fabric bag 5. Therefore, even if upward tensile force is applied to the pile foundation 9,
The lower foundation pile 1 significantly increases the shear pull-out resistance force to the ground 8 as compared with the case of only the steel pipe pile 2, and can reliably resist this tensile force.

[0014]

According to the present invention, by adopting the above-mentioned structure, the resistance to the tensile force acting from the upper structure can be increased, and both the compressive force and the tensile force can be dealt with at the same time. We will reduce the burden, realize lighter weight, smaller size, and lower cost. In addition, construction can be performed even on the ground where the grout is likely to be washed away, and the installation location is not chosen, so it is safe and highly reliable.

If a structure is provided in which a hole for grouting is provided in a portion of the pile body where there is no woven bag, the pile body and the ground are more closely adhered to each other to increase the resistance to tensile force and to further increase the strength of the pile foundation. Lightweight and compact.

If a structure is adopted in which a pair of upper and lower bag holding frames for the woven cloth bag are attached to the outer periphery of the pile body, the woven cloth bag hangs down or spreads when the foundation pile is inserted into the building hole, which hinders the insertion. Is easy to work with.

By adopting a construction in which a grout injection pipe connected to each hole of the pile body is provided, it is possible to eliminate grout in the hollow part of the pile, reduce the grout to be used, and press the grout in a short time. It can be done and work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a pile erection work of an embodiment.

FIG. 2 is an explanatory view showing a grout press-fitting state of the embodiment.

FIG. 3 is an explanatory view showing a grout injection hole of an example.

FIG. 4 is an explanatory view showing a cross section of a pile of an example.

FIG. 5 is an explanatory view showing a woven bag holding state of the embodiment.

FIG. 6 is an explanatory diagram showing a use state of the embodiment.

FIG. 7 is an explanatory diagram showing another example of the woven fabric bag of the embodiment.

[Explanation of symbols]

 1 Foundation pile 2 Steel pipe pile 2a Hole 2b Hollow part 3 Pipe 4 Check valve 5 Woven cloth bag 6 Bag holding frame 7 Grout 8 Ground 8a Construction hole 9 Pile foundation 9a Concrete foundation 10 Steel tower 10a Anchor 11 Self-propelled crane 12 Press-fitting apparatus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroo Uehara 6-32, Ichinoya, Kasuga-shi, Fukuoka Inside New Technology Koei Co., Ltd. (56) References JP-A-63-251519 (JP, A) 58-69037 (JP, U)

Claims (5)

(57) [Claims] 1. A grout which is provided with a plurality of annular woven cloth bags at predetermined intervals on the outer peripheral surface of the effective length of attachment of hollow piles used for pile foundations of large-sized structures at predetermined intervals, and which communicates from the inside of the piles into each woven cloth bag. provided with a hole for injection, mounting a check valve that allows flow only into the cloth bag in woven into the hole from the pile inside the pile
For grout injection from the inside to the outer peripheral surface of the part without the woven bag
Along with the provision of multiple holes, the flow from the inside to the outside of the pile
A foundation pile that is equipped with a check valve that allows only entry . 2. A long woven cloth bag is spirally wound around the outer peripheral surface of the effective attachment length portion of the hollow pile used for the pile foundation of a large structure to the ground, and the inside of the pile is put into the woven cloth bag. A foundation pile, characterized in that a plurality of holes for injecting grout are provided, and a check valve that allows only inflow into the woven bag from the inside of the pile is attached to the holes. 3. From the inside of the pile to the outer peripheral surface of the portion without the woven bag
There are multiple holes for grout injection, and the holes in the pile
With a check valve that allows only inflow from side to outside,
The foundation pile according to claim 2 . 4. The woven fabric bag is folded to make it compact.
Lightly from above and below, and at the outer periphery of the woven bag pile
The pair of upper and lower bag holding frames are
The woven bag mounting portion is provided on the upper side and the lower side, respectively.
Foundation pile according to 1 . 5. A state in which a woven bag is folded to be compact.
And hold it lightly from above and below, and
The pair of upper and lower bag holding frames do not prevent the expansion of the
The method according to claim 2, wherein the bag mounting portion is provided on each of the upper side and the lower side.
Or the foundation pile described in 3 .