JP2000080645A - Construction method for cast-in-place pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly inflate a bag at a specified position in a hole and to secure improvement of bearing power as a pile, horizontal bearing force and deforming performance in the case of improving bearing power as the pile, the horizontal bearing force and the deforming performance by inserting the bag in the drilled hole and filling a filler in this bag or in a cavity in the bag or between the bag and the hole. SOLUTION: Consolidation of the foundation of a head end part is carried out by providing a cylindrical bag fixing member 7 on a head end of a bag 2, injecting a filler 18 into a hole 3 through the bag fixing member 7 from an opening 6 of the head end of the bag 2 by a rod 5 to insert into the bag 2 and burying the bag fixing member 7 in the filler 18 in the case of constructing a cylindrical cast-in-place pile covered with the bag 2 by inserting the bag 2 into the drilled hole 3 and inflating the bag 2 by filling the filler 18 such as cement milk, mortar or concrete. Thereafter, the cylindrical cast-in- place pile covered with the bag 2 is constructed by inflating the bag 2 by discharging the filler 18 from the rod 5 into the bag 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to seismic reinforcement including liquefaction countermeasures, or, in the case of existing foundations, as the load on superstructures increases, the bearing capacity, the strength of the foundation itself (vertical and horizontal), and The present invention relates to a method of constructing a cast-in-place pile or a cast-in-place pile for a newly installed foundation for the purpose of improving the yield strength and the deformability of the foundation when the deformability is insufficient.

[0002]

2. Description of the Related Art As reinforcement of an existing foundation for the purpose of improving physical strength and deformation performance of the foundation, conventionally, as shown in FIGS. 31 and 32, an extra pile is provided outside an existing footing 31 and an existing pile 32. There is a method in which the footing 31 is additionally provided and the footing 31 is also added to improve the bearing capacity, bearing capacity, and deformation performance in the event of an earthquake.

However, in the method of increasing piles and the like, the space to be used is insufficient in terms of area only within the plane of the existing foundation, and is used in places where there are restrictions on land or restrictions on headspace just below the existing structure. Can not.

[0004] In addition to the above, there is a method of improving the ground of the entire lower and surrounding grounds to increase the ground strength immediately below the foundation or immediately below the existing piles in any case of a direct foundation such as a pile foundation or a cloth foundation. However, in the reinforcement by such a soil improvement method, unless the entire area immediately below the foundation or a wide area outside the foundation is improved, the predetermined performance cannot be satisfied, and since the bearing capacity of the existing pile is not considered in the design, Existing piles are wasted, resulting in higher costs.

[0005] Therefore, without increasing the area and without removing the existing foundation, it is possible to easily and surely improve the supporting force, the proof stress, and the horizontal deformation performance of the foundation. As a cast-in-place pile construction method directly under an existing foundation that can be used, there is a method proposed by the applicant in Japanese Patent Application No. 8-285200 (Japanese Patent Application Laid-Open No. 10-25737).

[0006] As shown in Figs.
When there is an existing foundation 21 having 22, a vertical through hole 24 is drilled in the existing foundation 21, and the ground is first cut with a water jet by a rod 25 using the through hole 24 and filled in a muddy state. Hole 23. In that case, muddy water such as bentonite may be replaced. The cut sand is discharged upward from the gap between the pipes as the double pipe or the triple pipe with the rod 25 inserted into the through hole 24.

Next, the bag 26 is inserted into the through hole 24 together with the rod 25, and cement milk,
A filler 28 such as mortar or concrete is filled and spread, and a columnar ground improvement body covered with a bag 26 is constructed as a pile 29. In the figure, reference numeral 30 denotes a support layer.

In this case, a predetermined hole is provided at an appropriate position of the bag 26 so that the filler 28 can flow out, and the filler 28 flows out of the hole into the space between the bag 26 and the hole 23 to fill the space. The bag 26 can be sandwiched by the filler 28 in this manner to improve the integrity of the bag 26, the filler 28, and the ground, and exhibit predetermined horizontal strength and deformation performance. Let it.

[0009]

When the method disclosed in Japanese Patent Application No. 8-285200 (Japanese Patent Application Laid-Open No. 10-25737) is carried out, a bag 26 is filled in a cut hole 23. At the stage of filling the material 28, if the specific gravity of the filler 28 in the bag 26 is lighter than the muddy water or the stabilizing liquid in the hole 23 or there is not much difference, the bag 26 floats or the bag 26 In some cases, the bag 26 may be shifted to one side in the hole 23 and may be displaced, or the bag 26 may be bent, so that the bag 26 cannot be evenly inflated at a predetermined position in the hole 23.

Further, earth and sand or slime may accumulate on the bottom of the cut hole 23, so that a predetermined tip supporting force as a pile cannot be obtained.

In particular, as described above, in a bag provided with a hole through which the filler 28 flows out, the filler 28 is formed through the hole through the hole.
When flowing into the gap between the bag and the bag, the amount of flow is not constant in the peripheral direction, or
There is a strong tendency that the bag 26 may float below or around the bag 26, or the bag 26 may float up, or the bag 26 may move to one side in the hole 23 and shift.

An object of the present invention is to solve the above-mentioned disadvantages of the prior art and to insert a bag into an excavated hole and fill the bag with a filler or to fill the bag or between the bag and the hole. When the filler is filled in the gap to improve the bearing capacity, horizontal strength and deformation performance of the pile, the bag can be reliably inflated at a predetermined position in the hole, and the bearing capacity of the pile The construction method of cast-in-place piles, which can ensure the improvement of horizontal strength and deformation performance, and can obtain a predetermined tip supporting force as a pile even when slime is deposited at the bottom of the drilled hole To provide.

[0013]

In order to achieve the above object, the present invention firstly inserts a bag into an excavated hole and fills the bag with a filler such as cement milk, mortar or concrete. In order to inflate the bag and form a cylindrical cast-in-place pile covered with the bag, a cylindrical bag fixing member is provided at the tip of the bag, and the filler is first inserted with a rod inserted into the bag. After filling the bag fixing member from the opening at the tip of the bag into the hole through the bag fixing member and embedding the bag fixing member in the filler to fix the tip portion, the filler from the rod is filled into the bag. And inflates the bag to form a cylindrical cast-in-place pile covered with the bag.

Second, at the lower end of the bag fixing member, there is provided an insertion guide / anchor into a hole formed in a hook shape or a cage shape with a steel material such as a reinforcing bar inside. The fourth aspect is to attach an anchor made of a plurality of reinforcing bars or the like to the lower end, and fourthly, to attach an anchor made of a plurality of reinforcing bars or the like spreading radially in the shape of an umbrella to the bag fixing member.

Fifth, the rod forms a thread around the distal end, and this thread is screwed into a thread formed on the inner peripheral surface of the bag fixing member. A plurality of protrusions are provided on the outer periphery of the bag, and the protrusions are detachably engaged with an L-shaped key hole formed on the peripheral surface of the bag fixing member.

Seventh, the rod is provided at its tip with a spout for discharging the filler for root consolidation, and a discharge port for discharging the filler into the bag on the side surface above the spout, and is inserted into the bag. The point is that the discharge port at the tip is dropped and closed with the filling material when the filler is discharged.

Eighth, a bag is inserted into the drilled hole, filled with a filler, and the bag is inflated to form a cylindrical cast-in-place pile covered with the bag. The rod for filling the material has a multi-tube structure, the lower end of one of the tubes is projected downward from the bottom of the bag, and the other tube is filled with the filling material. The point is to inject into the excavation hole below and perform root consolidation.

According to the first aspect of the present invention, a bag is inserted into an excavated hole, and a space between the bag and the hole is filled with a filler to fill a cylindrical cast-in-place pile. When creating
An opening is provided at the tip of the bag, a cylindrical bag fixing member is attached to the opening, and then the filler is discharged from the opening to the bottom of the hole, whereby the bag fixing member is fixed to the bottom of the hole with the filler. The tip is solidified. In this state, the bag is fixed to the bottom of the hole by the bag fixing member at the leading end.Therefore, even if the filler is discharged into the bag or into the gap between the bag and the hole, the bag floats or moves. Can be prevented, the bag can be reliably inflated at a predetermined position in the hole, and the supporting force, horizontal strength and deformation performance as a pile can be exhibited.

According to the second aspect of the present invention, in addition to the above-mentioned functions, a steel material such as a reinforcing bar is provided inside with a hook-like shape or an insertion guide / anchor in a cage-shaped hole is further provided. In addition to smooth insertion of the bag into the hole, it can reinforce the bag fixing member when the strength is not sufficient, and also reduce the filling pressure when filling the inside of the bag and the pulling force when pulling out the rod. The bag can be resisted and the tip of the bag can be firmly fixed and fixed.

According to the third aspect of the present invention, in addition to the above-mentioned operation, by attaching an anchor made of a plurality of reinforcing bars or the like, the reinforcing bars are pressed into the ground at the bottom of the hole so that the ground is formed. Make sure to firmly secure the tip of the bag by using the pull-out resistance.

According to the fourth aspect of the present invention, in addition to the above-described operation, the anchor is also provided in the horizontal direction by attaching a plurality of reinforcing bars or the like radially extending in the umbrella bone shape. The movement of the bag can be more reliably prevented.

According to the fifth aspect of the present invention, in addition to the above-mentioned operation, the bag and the rod can be integrally inserted into the hole by temporarily fixing the rod to the bag fixing member by the screw portion. After consolidation, the rod can be detached from the bag fixing member and pulled up by rotating the rod, and the process can smoothly proceed to the next step of filling the filler into the bag.

According to the present invention described in claim 6, according to claim 1,
In addition to the function of the present invention, by temporarily fixing the rod to the bag fixing member by locking the projection with the key groove, the bag and the rod can be inserted integrally into the hole, After solidification of the rod, the rod can be released from engagement with the bag fixing member by slightly rotating the rod, the rod can be pulled up, and the process can smoothly proceed to the next filling step of the filling material into the bag. .

According to the seventh aspect of the present invention, in addition to the above-described operation, if a bag is attached to a rod and inserted into a hole, the root can be solidified as it is using a single rod. And the subsequent filling of the bag with the filler can be performed continuously.

According to the eighth aspect of the present invention, one tube of the multi-tube structure projects below the bag, and the tip of the bag is fixed by this tube. Therefore, even if the filler is discharged into the bag or into the gap between the bag and the hole, the bag can be prevented from floating or moving, and the bag can be reliably inflated at a predetermined position in the hole. Can be After that, if a filler is injected into the drilling hole from a tube projecting below the bag, the slime and the like deposited here are solidified to obtain a supporting force.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a vertical front view of a first step showing a first embodiment of a casting method of a cast-in-place pile according to the present invention, and FIG. 2 is a vertical front view of a second step of the same.
As with the cast-in-place pile constructed by the method shown in No. 285200, the existing foundation (footing) 1 with the existing pile has a diameter of 150
A vertical through hole 4 of about mm to 250 mm is formed, and the ground 3 is cut by using the through hole 4 by, for example, a jet method.

In the present invention, the cylindrical bag 2 made of high-strength fiber is mounted around the rod 5 in a closed state, and the rod 5 and the bag 2 are inserted into the hole 3 through the through hole 4. However, an opening 6 is formed at the lower end of the bag 2 as shown in FIG. 4, and a bag fixing member 7 for fixing the root is fixed to the opening 6.

The bag fixing member 7 is made of a synthetic resin such as steel or plastic as a material. For example, as shown in FIG. 3, the bag fixing member 7 has a thread winding shape in which flanges 7a and 7b are protruded above and below a cylindrical body 7c. Was provided with a plurality of bolt holes at appropriate intervals. In addition, a polygon other than a cylinder may be used as long as it is cylindrical.

In order to fix the bag fixing member 7 to the opening 6 at the lower end of the bag 2, the flange 7 a contacts the outer periphery of the opening 6, while the ring-shaped plate 9 , The bag 2 is sandwiched between the flange 7 a and the plate 9, and the three members are joined by bolts 8.

FIG. 5 shows another example of the bag fixing member 7 which is formed in a cylindrical shape without a flange. In order to fix the bag fixing member 7 having such a shape to the bag 2, the opening 6 is provided. The upper end of the bag fixing member 7 is inserted, and the periphery of the opening 6 of the bag 2 is wrapped around the upper part of the bag fixing member 7 and fixed with a band material 10.

The insertion guide 11 is further attached to the bag fixing member 7 attached to the lower portion of the bag 2 as necessary. When the bag fixing member 7 has a thread winding shape as shown in FIG. 4, the insertion guide 11 is formed of a cylindrical body having a diameter corresponding to the outer diameter of the lower flange 7b, and the bag fixing member 7 is shown in FIG. In the case of such a simple cylindrical shape, many rows of steel materials such as reinforcing bars having a diameter matching the outer diameter of the cylindrical body are arranged, and the lower opening 11 is formed.
b is provided with a tapered portion 11a so as to be tapered. In this case, the width of the opening 11b is formed equal to the outer diameter of the rod 5.

Further, an anchor can be attached to the bag fixing member 7 separately. As shown in FIGS. 5 and 6, this anchor is formed by projecting a plurality of reinforcing bars 12 downward from the cylindrical body or the flange 7b of the bag fixing member 7.
The head nut 12a may be provided at the lower end as shown in FIG.

Further, as shown in FIG. 7, a plurality of rebars 13 can be attached to the upper flange 7a of the bag fixing member 7 as anchors so as to spread radially in the shape of an umbrella.

As shown in FIG. 8, the lower end of the rod 5 is formed in a conical shape, and the side portion thereof is provided with, for example, a radially four-way spout 5a of a filling material for rooting, and the upper side portion thereof is provided with a spout 5a. A discharge port 5b for discharging the filler into the bag 2 is provided facing the discharge port 5b. An O-ring for stopping water is provided inside the discharge port 5b.
A closing pipe 15 is provided via the support 14 and is supported by a shear pin 16 to support the closing pipe 15 inside the discharge port 5b.

In the drawing, reference numeral 17 denotes a dropping material such as a plug which removes the shear pin 16 and closes the jet port 5a. The tip of the dropping material 17 is formed to have the same conical shape as the tip of the rod 5. .

As means for fixing the rod 5 to the bag fixing member 7, for example, as shown in FIG. 9, a screw portion 5 c is formed on the outer peripheral surface of the rod 5, and a screw is formed inside the cylindrical body 7 c of the bag fixing member 7. A portion 7d is formed, and the two screw portions 5c and 7d are screwed together.

Alternatively, as shown in FIG. 10, an L-shaped key hole 7e is formed opposite to the side of the cylindrical body of the bag fixing member 7, while the rod 5 has a projection inserted into the key hole 7e. 5d is projected, and the projection 5d is locked in the key hole 7e.

The rod 5 is inserted into the bag 2 having the bag fixing member 7 fixed to the tip as described above, and the tip of the rod 5 is screwed with the threaded portions 5c and 7d, or the key hole 7e and the projection 5 are inserted.
d, the bag 2 is temporarily fixed to the bag fixing member 7, and the bag 2 and the rod 5 are inserted into the hole 3 with the bag 2 closed as shown in FIG. If you do, rod 5
The filler 18 such as cement milk, mortar or concrete is ejected from the injection port 5a at the tip of the nozzle. At this time, since the discharge port 5b on the upper part of the rod 5 is closed by the closing pipe 15, the filler 18 does not discharge into the bag 2 at the same time.

The insertion of the rod 5 is smoothly performed by the insertion guide 11, and when a reinforcing bar 12 serving as an anchor is provided, this is pressed into the ground at the bottom of the hole 3.
Is installed, the horizontal reinforcing bars 13 also radially expand as the bag 2 spreads.

In this manner, the filler 18 is jetted to the height of the bag fixing member 7, and is stirred and mixed with the sediment sedimented therein to consolidate the tip. In this state, as shown in FIG. 1, the bag fixing member 7 and the insertion guide 11 are embedded in the filler 18, and when reinforcing bars 12 and 13 are provided, as shown in FIG.
12 is fixed in the filling material 18 while being pressed into the ground,
13 is fixed in the filler 18 spreading horizontally in the radial direction as shown in FIG.

With the filler 18 solidified to some extent, the rod 5 is rotated to release the screwing of the threaded portions 5c and 7d, or to release the engagement between the key hole 7e and the projection 5d, and The lock with the fixing member 7 is released, and the rod 5 is pulled up into the bag 2 as shown in FIG.

At this time, since the insertion guide 11 also serving as an anchor and the reinforcing bars 12 and 13 serving as anchors are attached to the bag fixing member 7, even if the rod 5 is pulled out, the bag is fixed by pulling resistance against the ground. The member 7 is securely left in the stiffening portion 19.

A dropping material 17 is inserted into the rod 5 pulled up into the bag 2 from above, and a filler 18 such as mortar is further poured into the rod 5 from above, thereby dropping the dropping material 17.
Is pushed under the rod 5. This allows the Sharpin 16
Is removed and the dropping material 17 reaches the lower end of the rod 5, so that the ejection port 5 a formed here is closed by the dropping material 17.

The discharge pipe 5b formed on the side of the rod 5 has the closed pipe 15 removed by removing the shear pin 16, and the discharge port 5b is opened. Therefore, the rod 5
When the filling material 18 is injected into the inside, it flows out from the discharge port 5b into the bag 2, the filling material 18 fills the bag 2, and the bag 2 spreads in the hole 3. At this time, since the tip of the bag 2 is fixed to the root fixing portion 19 via the bag fixing member 7, the bag 2 can resist the filling pressure, and the bag 2 does not move or bend.

By expanding the bag 2 in a cylindrical shape in this way, a cylindrical cast-in-place pile is formed, and the strength, vertical and horizontal directions are the same as when a so-called support pile is constructed immediately below the existing foundation. This columnar improved body exerts the proof strength and the horizontal deformation performance.

FIGS. 14 to 16 show a second embodiment.
As shown in FIG. 14, using a triple pipe rod 20 of the high-pressure injection replacement method, a stable liquid and air are injected from the injection port 20a to bore holes, or holes are drilled by injection with water and air. The hole 3 is formed by filling a stable liquid such as muddy water into the hole 3 from the lower injection port 20b to stabilize the hole wall.

Next, as shown in FIG. 15, the triple tube rod 20 is once pulled up, and then the bag fixing member 7, the insertion guide
11 and the bag 2 are attached and inserted again into the hole 3, and the filler 18 such as cement slurry is injected into the bottom of the hole 3 through the injection port 20 b at the lower part of the triple tube rod 20 and agitated to consolidate the roots. .

After the solidification portion 19 has solidified, the triple tube rod
While pulling up 20, the bag 2 is filled with a filler 18 such as cement slurry from the upper injection port 20c to spread the bag 2. In this case, if a predetermined opening 2a is formed in the bag 2, the filler 18 flows out of the opening 2a into the space between the bag 2 and the hole 3, and is filled here, and the bag 2 is filled with the filler. A pile in which 18 is further integrated is created.

FIGS. 17 to 19 show a third embodiment. In the second embodiment, after a hole is drilled with a triple pipe rod 20 of a high-pressure injection displacement method, the hole is once pulled up, and then a bag 2 is attached and a hole 3 is formed.
In the third embodiment, holes are drilled with a jet of water or a stable liquid and air with the bag 2 attached as shown in FIG. 17, and then, as shown in FIG. Jet digging of the consolidation part with cement milk or cement bentonite liquid and air, and consolidation of this part. And finally the triple tube rod as shown in FIG.
From 20, a filling material 18 such as cement milk or mortar is filled in the bag 2.

Thus, even if slime or the like is deposited at the tip of the pile, it can be solidified, and a solidified body having a large supporting force can be obtained.

FIGS. 20 to 23 show a fourth embodiment. In the third embodiment, the bag 2 is attached to the triple pipe rod 20 and the holes 3 are formed.
After being inserted into the inside of the bag, the filling material 18 was injected into the bag 2 after the root was solidified. In the fourth embodiment, a multi-tube rod with a double tube or a triple tube rod 20 is used. 2
After filling the inside of the bag 2 with the outer tube, the filler is injected into the slime at the bottom of the hole 3 from the inner tube projecting downward. And solidify this part to form a solid body with a large supporting force.

In this case, the filling material 18 is injected into the bag 2 before the consolidation is performed, but since the bottom of the bag 2 is fixed to the inner tube, the filling material 18 is injected into the bag 2 The bag 2 does not move.

Although the above embodiment has been described in connection with the case where the work is carried out immediately below the existing foundation, the present invention is not limited to this.

[0054]

As described above, in the method for constructing a cast-in-place pile according to the present invention, a bag is inserted into an excavated hole, and a filler is filled in the bag or in the space between the bag and the hole. In order to improve the bearing capacity, horizontal proof stress and deformation performance as a pile by filling the bag, a bag fixing member is provided at the lower end of the bag and it is fixed at this part, so that the bag is injected when the filler is injected. The bag can be prevented from rising, moving, or bending in the hole, and as a result, the bag can be reliably inflated at a predetermined position in the hole, thereby ensuring the improvement of the bearing capacity, horizontal strength, and deformation performance as a pile. It can be. Further, by solidifying the tip of the pile, slime and the like deposited here can be solidified, and a solidified body having a large supporting force can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a first step showing a first embodiment of a method for constructing a cast-in-place pile according to the present invention.

FIG. 2 is a vertical sectional front view of a second step showing the first embodiment of the casting method for cast-in-place piles of the present invention.

FIG. 3 is a perspective view showing an example of a bag fixing member used in the casting method of the cast-in-place pile according to the present invention.

FIG. 4 is a longitudinal sectional front view in which an insertion guide is attached to a bag fixing member used in the casting method for cast-in-place piles of the present invention.

FIG. 5 is a perspective view in which an insertion guide and an anchor are attached to another example of the bag fixing member used in the casting method of the cast-in-place pile according to the present invention.

FIG. 6 is a longitudinal sectional front view in which an insertion guide and an anchor are attached to a bag fixing member used in the casting method of the cast-in-place pile according to the present invention.

FIG. 7 is a longitudinal sectional front view in which a horizontal anchor is attached to a bag fixing member used in the casting method of the cast-in-place pile according to the present invention.

FIG. 8 is a vertical sectional front view of a rod used in the method for constructing a cast-in-place pile according to the present invention.

FIG. 9 is a vertical sectional front view showing an example of a locked state of a rod and a bag fixing member used in the method of constructing a cast-in-place pile according to the present invention.

FIG. 10 is a perspective view showing a locking portion between the bag fixing member and the rod used in the casting method of the cast-in-place pile according to the present invention.

FIG. 11 is a longitudinal sectional front view showing a locking portion of a rod used in the casting method for cast-in-place pile of the present invention with a bag fixing member.

FIG. 12 is a longitudinal sectional front view showing a first embodiment of a method of constructing a cast-in-place pile according to the present invention, in which an anchor is fixed to a ground.

FIG. 13 is a longitudinal sectional front view showing a first embodiment of a method of constructing a cast-in-place pile according to the present invention, in which a bone anchor of an umbrella is fixed to a solidified portion.

FIG. 14 is a vertical sectional front view of a first step showing a second embodiment of the casting method for cast-in-place piles of the present invention.

FIG. 15 is a longitudinal sectional front view of a second step showing a second embodiment of the method for constructing a cast-in-place pile according to the present invention.

FIG. 16 is a vertical sectional front view showing a third step of the second embodiment of the method for constructing a cast-in-place pile according to the present invention.

FIG. 17 is a longitudinal sectional front view of a first step showing a third embodiment of the casting method for cast-in-place piles of the present invention.

FIG. 18 is a vertical sectional front view of a second step showing the third embodiment of the method for constructing a cast-in-place pile according to the present invention.

FIG. 19 is a vertical sectional front view of a third step showing a third embodiment of the method of constructing a cast-in-place pile according to the present invention.

FIG. 20 is a vertical cross-sectional front view of a first step showing a fourth embodiment of the casting method for cast-in-place piles of the present invention.

FIG. 21 is a longitudinal sectional front view of a second step showing a fourth embodiment of the method of constructing a cast-in-place pile according to the present invention.

FIG. 22 is a vertical sectional front view of a third step showing a fourth embodiment of the method of constructing a cast-in-place pile according to the present invention.

FIG. 23 is a vertical cross-sectional front view of a fourth step showing a fourth embodiment of the casting method for cast-in-place piles of the present invention.

FIG. 24 is a vertical sectional front view showing one example of a conventional casting method for cast-in-place piles.

FIG. 25 is a plan view showing an example of a conventional casting method for cast-in-place piles.

FIG. 26 is a front view of a first step of a conventional casting method for cast-in-place piles.

FIG. 27 is a front view of a second step of the conventional casting method for cast-in-place piles.

FIG. 28 is a front view of a third step of the conventional casting method for cast-in-place piles.

FIG. 29 is a front view of a fourth step of the conventional casting method for cast-in-place piles.

FIG. 30 is a front view of a fifth step of the conventional casting method for cast-in-place piles.

FIG. 31 is a vertical sectional front view showing another conventional example.

FIG. 32 is a plan view showing another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Existing foundation 2 ... Bag 2a ... Opening 3 ... Hole 4 ... Through-hole 5 ... Rod 5a ... Spout port 5b ... Discharge port 5c ... Screw part 5d ... Projection 6 ... Opening 7 ... Bag fixing member 7a, 7b ... Flange 7c ... Cylindrical body 7d Screw part 7e Key hole 8 Bolt 9 Plate 10 Band material 11 Insertion guide 11a Tapered part 11b Opening 12 Reinforcing bar 12a Head nut 13 Reinforcing bar 14 O-ring 15 Closed pipe 16 … Shear pin 17… Dropping material 18… Filling material 19… Rooting part 20… Triple pipe rods 20a, 20b, 20c…
Injector 21 ... Existing foundation 22 ... Existing pile 23 ... Hole 24 ... Through hole 25 ... Rod 26 ... Bag 28 ... Filler 29 ... Pile 30 ... Support layer 31 ... Footing 32 ... Existing pile 33 ... Increased pile

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Yamanaka 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Akiyama Akiyama 2-9-1-1, Tobita-Shibi, Chofu-shi, Tokyo Kashima Construction Co., Ltd.Technical Research Institute (72) Kazuo Hira 2-9-1-1, Tobita-Shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd.Technical Research Laboratory (72) Inventor Akihiko Ikeda 1-4-6 Moto-Akasaka, Minato-ku, Tokyo No. Chemica Lugrout Co., Ltd. F-term (reference) 2D040 AA01 BA09 BB03 BD05 CA01 2D041 AA01 BA03 BA13 BA16 BA33 CA01 CB01 CB05 DA02 EA00 EB08 GA01 GB01 GD02

Claims (8)

[Claims] 1. A bag is inserted into an excavated hole, and the bag is filled with a filler such as cement milk, mortar or concrete to inflate the bag, and a cylindrical cast-in-place pile covered with the bag is formed. In the case of forming, a cylindrical bag fixing member is provided at the tip of the bag, and the filler is first injected into the hole through the bag fixing member from the opening at the tip of the bag with a rod inserted into the bag. After burying the bag fixing member in the filling material and solidifying the tip portion, the filling material from the rod is discharged into the bag to inflate the bag, and the cylindrical shape covered with the bag is cast in place. Construction method of cast-in-place pile characterized by creating pile. 2. The casting method for cast-in-place piles according to claim 1, wherein an insertion guide / anchor is provided at a lower end of the bag fixing member in a hole formed in a hook shape or a cage shape with a steel material such as a reinforcing bar inside. 3. The method for constructing a cast-in-place pile according to claim 1, wherein a plurality of anchors are attached to a lower end of the bag fixing member. 4. The method for constructing a cast-in-place pile according to claim 1, wherein the bag fixing member is provided with a plurality of anchors, such as a plurality of reinforcing bars, extending radially in the shape of an umbrella in a radial direction. 5. The rod according to claim 1, wherein a threaded portion is formed around the distal end portion, and the threaded portion is screwed to a threaded portion formed on an inner peripheral surface of the bag fixing member. Construction method of cast-in-place pile. 6. The rod according to claim 1, wherein a plurality of projections are provided on an outer periphery of a tip portion, and the rod is detachably engaged with an L-shaped key hole formed on a peripheral surface of the bag fixing member. Construction method of cast-in-place pile described. 7. A rod is provided with a spout for discharging filler for consolidation at a tip thereof, and a discharge port for discharging a filler into a bag on a side surface located above the spout to fill the bag. The method for constructing a cast-in-place pile according to any one of claims 1 to 6, wherein at the time of discharging the material, the spout at the tip is dropped and closed with the material. 8. A bag is inserted into an excavated hole, the bag is filled with a filler, and the bag is inflated to form a cylindrical cast-in-place pile covered with the bag. The filling rod has a multi-tube structure, the lower end of one tube is projected downward from the bottom of the bag, and the other tube is filled with the filling material, and then the lower portion of the bag is filled from the one tube. A method for constructing a cast-in-place pile, characterized in that it is injected into a borehole and solidified.