JPH10266199A - Installation method for double filling pipe with tip packer and steel core mortar pole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability of a foundation reinforcing work while maintaining the existing bridge piers by inserting a steel rod having a packer into a steel rod introducing pipe, by accompanying and fixing a group pipe at the outer surface side of the steel rod introducing pipe, and sealing the spaces among a casing inner surface, outer surface of the steel rod introducing pipe and the outer surface of a group pipe with a tip portion of the steel rod introducing pipe. SOLUTION: A steel rod 15 with a plurality of steel rod packers 13 externally fitted at predetermined spacings are inserted. Also, a grout pipe 15 is accompanied and fixed at the external surface side of the cylindrical pipe 12 and the gaps among the casing inner surface, external surface of cylindrical pipe and external surface of grout pipe are sealed by the tip portion of the cylindrical pipe 12 by the tip packer 16 for cylindrical pipe installation. The steel rod 14 with packer, a cylindrical pipe 12 and grout pipe 15 can be inserted in one united body into the casing 11 and therefore the double filling pipe 10 with tip packer can be easily inserted to the casing 11 left after drilling in the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a double injection pipe with a tip packer and a steel core mortar pile, which are used for reinforcing existing foundations such as piers.

[0002]

2. Description of the Related Art Conventionally, in order to reinforce the foundations of elevated roads and viaducts, existing roads and bridges cannot be demolished. Therefore, existing pillars must be maintained as they are to carry out reinforcement work. Must. For this reason, in the foundation work to prevent the pillar from falling or falling out, a pile hole is excavated from the outer periphery of the existing pillar, grout is injected into the pile hole with a grout injection pipe, and after the injection, the steel core is inserted. Insert or insert the steel core with the packer stepwise into the pile hole and pull up the grout injection pipe while sequentially injecting grout between the packers attached to the steel core to form the steel core mortar pile In addition, a construction method is adopted in which a reinforced concrete foundation for reinforcing pillars is constructed on the formed piles to prevent the pillars from falling down or coming off.

[Problems of the prior art] In such a conventional technology, it is necessary to stake around an existing pillar, and an excessively large excavator cannot be used because of the existence of an elevated portion. . Excavation in the vertical direction is easy, but excavation in the diagonal direction is difficult and difficult. Therefore, there is a problem that workability of construction is poor and work efficiency cannot be increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems in the prior art, and a specific problem set for the purpose of solving the problem is to perform while maintaining an existing pier or the like. An object of the present invention is to provide a method for installing a double injection pipe with a tip packer and a steel core mortar pile, which has improved workability in foundation reinforcement work.

[0005]

Means for Solving the Problems Claim 1 of the present invention
The double injection pipe with a tip packer according to the present invention is a steel rod introduction pipe inserted into a casing type excavating casing left in the soil, a steel rod with a packer inserted into the steel rod introduction pipe, and the steel rod A grout pipe attached and fixed on the outer surface side of the introduction pipe, and a tip packer for sealing between the inner surface of the casing, the outer surface of the steel rod introduction pipe, and the outer surface of the grout pipe at the tip of the steel rod introduction pipe. It is characterized by the following.

According to a second aspect of the present invention, in the method for constructing a steel core mortar pile, the casing is left in the soil after being excavated by the casing type excavation, and the double injection pipe with the tip packer according to the first aspect is placed in the casing. And the mortar is injected from the end of the grout pipe by pulling up together with the casing while leaving the steel bar with the packer.

Further, in the method for constructing a steel core mortar pile according to claim 3, the mortar is injected by injecting the mortar below a steel rod packer located at a lowermost end from a tip of the grout pipe and consolidating the mortar. After the consolidation, the double injection pipe with the tip packer together with the casing is pulled up to the position of the steel rod packer located at the upper stage while leaving the steel rod with the packer, and the mortar is placed below the steel rod packer adjacent to the grout pipe tip. , And repeating the injection process for the number of stages of disposing the steel bar packers.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the following embodiments of the present invention, a case where a foundation of a pier is reinforced will be described. However, this embodiment is specifically shown for better understanding of the gist of the invention, and does not limit another embodiment unless otherwise specified.

[Structure] Double injection tube 10 with tip packer
As shown in FIGS. 1 and 2, a cylindrical pipe 12 as a steel rod introducing pipe inserted into a casing 11 and a plurality of steel rod packers 13 inserted into the cylindrical pipe 12 are externally fitted at predetermined intervals. A steel rod 14, a grout pipe 15 attached and fixed to the outer surface side of the cylindrical tube 12, and a cylindrical tube mounting for sealing a gap between the inner surface of the casing, the outer surface of the cylindrical tube, and the outer surface of the grout pipe at the tip of the cylindrical tube 12. To form an injection tube having the tip packer 16 of FIG.

Drilling shaft 17 for casing type drilling (FIG. 5)
After drilling, leave the casing 11 in the hole and remove the rod 1
A drilling shaft configured to extract only 9 is used. For example, a rod 19 that is attached to a relatively small drilling machine 18 (FIG. 4) such as an impact drill, rotates the casing 11, is inserted into the casing 11, and used in a different operation from the casing 11 for use. An excavation shaft in which an impact in the axial direction is given to (FIG. 5) so that the excavation is performed, and after drilling, only the rod 19 can be extracted while the casing 11 is left in the hole can be exemplified.

A plurality of steel bar packers 13 are fixed around the steel bar portion 14a of the steel bar 14 with a packer at substantially equal intervals, and have a support function when the steel bar 14 with the packer is inserted into the cylindrical tube 12. It also has a function of sealing a gap formed between the steel rod with a packer 14 and the cylindrical tube during mortar injection. The steel bar packer 13 is made of a hard synthetic rubber, and is made of a material having high pressure resistance and abrasion resistance and little change over time.

The tip packer 16 is provided at the tip of the cylindrical tube 12 and has a sealing function of a gap formed between the cylindrical tube 12 to which the grout pipe 15 is fixed during mortar injection and the casing 11. In order to effectively exhibit the sealing function, a material which is softer and more flexible than the steel bar packer 13 among hard synthetic rubbers, and which is adapted to a complicated shape to enhance the sealing property is selected and used.

The grout pipe 15 is disposed in parallel with the cylindrical pipe 12, protrudes slightly forward from the tip of the cylindrical pipe 12, and a contact portion with the cylindrical pipe 12 is fixed by welding or the like, and is integrated with the cylindrical pipe 12. Formed. The outer surfaces of the integrated grout pipe 15 and cylindrical pipe 12 are attached to a tip packer 16.
So that when inserted into the casing 11, the gap between the casing 11 and the casing 11 is filled.

[Construction method] To reinforce a pier using such a double injection pipe 10 with a tip packer, first, as shown in FIG. Digging down with a shovel or other drilling machine,
The area where the primary excavation part 22 can be removed and a reinforced concrete foundation can be cast is provided, and as shown in FIG.

Then, as shown in FIG. 5, a drilling shaft 17 is attached to drill a hole. In drilling, if the length of the drilling shaft 17 is not enough before reaching the predetermined depth,
The hole is drilled while repeating the addition until a predetermined depth is reached. When a predetermined depth is reached, as shown in FIG.
7 and only the rod 19 is pulled out and removed.
Leave 1 in the soil.

Thereafter, as shown in FIG.
1. Insert the double injection tube 10 with the tip packer into the casing 1 and position the tip of the double injection tube 10 with the tip packer to project slightly forward (downward) from the tip of the casing 11. Then, a mortar injection pipe (not shown) is connected to the grout pipe 15 so that the mortar can be injected into a drilled hole for forming a pile hole.

As shown in FIG.
Until the tip packer 16 is located at the position of the lowermost steel bar packer 13 attached to the bottom, all members except the steel bar 14 with a packer are pulled up, mortar is injected from the grout pipe 15, and the lowermost steel bar packer 13 is mounted. Mortar pile 2 having a steel rod portion 14a located below the mandrel as a mandrel.
4 to form a lowermost end portion 24a and consolidate the roots.

After consolidation, as shown in FIG.
All the members except the steel bar 14 with the packer are pulled up to the position of the steel bar packer 13 in the upper stage, and mortar is injected from the grout pipe 15 and the mortar pile 2 is solidified.
A part 24 of the mortar pile 24 is located above the lowermost end 24a
b is formed. Then, this process is repeated in order from the bottom to the required number of stages, and a part of the mortar pile 24 is
From the top to the top end 24e.
The mortar pile 24 having a predetermined length is formed as shown in FIG.

The steel core mortar pile 24 provided with the steel bar 14 with the packer formed as described above as a core material is shown in FIG.
As shown in FIG. 1, a plurality of piles are formed diagonally downward in different directions with substantially the same location as a base point, and the upper end portion 24f is bundled. The reinforcing bar cage 26a is assembled in the space from which the steel bars have been removed, the upper end 24f is fixed to the reinforcing bar cage 26a, concrete is poured into the portion where the reinforcing bar basket 26a is provided, and the concrete is cured for a certain period to form the reinforced concrete foundation 26.

[Operation / Effect] In the double injection pipe 10 with the tip packer, since the steel rod 14 with the packer, the cylindrical pipe 12 and the grout pipe 15 can be integrally inserted into the casing 11, the soil is removed after the drilling. The double injection pipe 10 with the tip packer can be easily inserted into the casing 11 left inside, and the workability is improved, which can contribute to a reduction in time and cost.

In the method of manufacturing the steel core mortar pile 24, after drilling, the steel core mortar pile 24 can be formed efficiently, which can contribute to cost reduction and leave the double injection pipe in the soil. By being inserted into the used casing 11, the construction accuracy is improved and the construction quality is improved. In addition, a relatively small excavator can be used for drilling, and it is easy to work not only vertically but also diagonally, so it can be done quickly.
Cost can be reduced.

The reinforced concrete foundation 26 having the steel core mortar pile 24 as a foundation pile is formed so as to surround the base of the pier 21, so that when the pier 21 is inclined due to an earthquake or the like, the base of the pier 21 Even if a force is applied in the direction in which the base 26 rises, the steel core mortar pile 24 extending below the foundation 26 is pulled and resists, preventing the foundation 26 from lifting and a force in a direction in which the inclination of the pier 21 is returned. To prevent the pier 21 from falling down.

[Alternative Embodiment] This embodiment has been specifically described for better understanding of the spirit of the invention, and does not limit the alternative embodiment. Therefore,
Changes can be made without departing from the spirit of the invention. For example,
The steel rod introducing pipe is not limited to a cylindrical pipe, and may have a cross section other than a circle, such as a partially crushed circle, ellipse, or polygon. The tip packer is made of a hard synthetic rubber. However, even a material having inferior durability, such as foamable plastic, can be used as long as its use period is limited to a short period. In order to make the gap between the casing including the grout pipe and the cylindrical pipe uniform, a packer on the outer peripheral side of the cylindrical pipe may be provided as an intermediate packer at a position other than the front end in addition to the front end packer. Further, as for the fixing of the grout pipe to the cylindrical pipe, a clamp using a belt or a rivet may be used instead of welding.

[0024]

As described above, in the double injection pipe with the tip packer according to the first aspect of the present invention, the steel rod with the packer and the grout pipe are precisely used by using the casing left in the soil after excavation. And the steel bar packer and the tip packer seal the unnecessary gap generated between the steel bar introduction tube and the steel bar with the packer and between the casing and the steel bar introduction tube. The mortar can be injected into a required range without flowing backward in a pipe such as a casing or a steel rod introduction pipe, so that workability is good, and a steel core mortar pile can be cast efficiently with high accuracy.

In the method for constructing a steel core mortar pile according to claim 2, after drilling by casing type excavation, the casing is left in the soil, and a double injection pipe with a tip packer is inserted into the casing. By pulling up the double injection pipe with the tip packer together with the casing while leaving the steel rod with the packer and injecting the mortar into the drilled hole from the grout pipe tip, it is possible to inject the mortar at a higher pressure than before. It is possible to form a pile with a larger diameter than the conventional method, it is possible to arrange a steel rod with a packer at substantially the center of the pile, and to pile strongly reinforced by the steel rod part of the steel rod with a packer. It is possible to form the cast-in-place steel core mortar pile with good workability and high accuracy, and to reduce the construction cost.

In the method for constructing a steel core mortar pile according to the third aspect, the mortar is injected below the steel bar packer located at the lowermost end from the grout pipe tip and solidified. Pull up the double injection pipe with the steel rod packer to the position of the steel rod packer located at the upper stage while leaving the steel rod with the packer, and inject mortar below the adjacent steel rod packer from the end of the grout pipe. By repeating the same number of steps, the mortar can be injected reliably from the bottom, the construction of the cast-in-place steel core mortar pile can be performed with high accuracy, and the construction quality can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a double injection tube with a tip packer according to an embodiment of the present invention.

FIG. 2 is a partial longitudinal sectional view showing a double injection tube with a tip packer according to an embodiment of the present invention.

FIG. 3 is an explanatory side sectional view showing primary excavation in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

FIG. 4 is an explanatory side sectional view showing installation of a drilling machine in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

FIG. 5 is an explanatory side sectional view showing drilling holes in the method of constructing a steel core mortar pile according to an embodiment of the present invention.

FIG. 6 is an explanatory side sectional view showing rod removal in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

FIG. 7 is a side sectional explanatory view showing insertion of a double injection pipe with a tip packer in a method of constructing a steel core mortar pile according to an embodiment of the present invention.

FIG. 8 is an explanatory side cross-sectional view showing a method of solidifying a steel core mortar pile according to an embodiment of the present invention.

FIG. 9 is an explanatory side sectional view showing a mortar injection procedure in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

FIG. 10 is an explanatory side sectional view showing a completed steel core mortar pile in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

FIG. 11 is an explanatory side sectional view showing the construction of a reinforced concrete foundation after pile driving in the method of constructing a steel core mortar pile according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Double injection pipe with tip packer 11 Casing 12 Cylindrical pipe (steel rod introduction pipe) 13 Steel rod packer 14 Steel rod with packer 15 Grout pipe 16 Tip packer 17 Drilling shaft (for casing type drilling) 18 Drilling machine 19 Rod 21 Pier 22 Primary excavation part 24 Steel core mortar pile 26 Reinforced concrete foundation

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naota Itoyama 2-16-2 Minami Kamata, Ota-ku, Tokyo Tone Underground Technology Co., Ltd. (72) Inventor Yukei Baba 2060 Shiroyama, Kamiwada, Yamato-shi, Kanagawa IT Engineering Co., Ltd.

Claims (3)

[Claims] 1. A steel rod introducing pipe inserted into a casing type excavating casing left in the soil, a steel rod with a packer inserted into the steel rod introducing pipe, and an outer surface side of the steel rod introducing pipe. A tip packer comprising: a grout pipe attached and fixed; and a tip packer for sealing between the inner surface of the casing, the outer surface of the steel rod guide tube, and the outer surface of the grout pipe at the tip of the steel rod introduction pipe. With double injection tube. 2. After excavating by casing type excavation, the casing is left in the soil, and the double injection pipe with the tip packer according to claim 1 is inserted into the casing, and the casing is inserted together with the casing while leaving the steel rod with the packer. A method for constructing a steel core mortar pile, comprising raising and injecting mortar from a grout pipe tip. 3. The mortar is poured under a steel bar packer located at the lowermost end from the tip of the grout pipe and solidified. After the solidification, the double pouring pipe with the tip packer is installed together with the casing. The mortar is pulled up to the position of the steel bar packer located at the upper stage while leaving the steel bar with the packer, and the mortar is injected below the steel bar packer adjacent to the end of the grout pipe. 3. The method of claim 2, wherein the pile is repeated every minute.